Precious Metal Purification Equipment

— Turnkey Precious Metal Purification Equipment

A YuSai precious metal purification equipment line is an engineered train that takes crude, doré, alloyed or concentrated precious-metal feed and delivers certified fine metal — 99.99% (4N) gold and silver as standard, with 99.999% (5N) reachable on a second electrolytic pass, platinum and palladium at 99.95% or above and rhodium at 99.90%. Purification is built around the impurity profile of your feed rather than around a single machine: electrolytic purification cells for anode-grade metal, aqua regia dissolution and selective precipitation for mixed and alloyed scrap, solvent extraction for the platinum group metals, and a melting, casting and granulation stage that keeps the purity the chemistry achieved. Every project starts with a laboratory assay of your own sample, runs on a closed loop for acid fumes, NOx and wastewater, and closes with a documented metal balance and a Certificate of Analysis naming the test method behind every purity figure.

Product Overview

Precious metal purification equipment is the stage of a refinery that removes the impurities still carried by already-concentrated precious-metal feed and lifts it to a defined, saleable fineness. Where recovery captures metal out of a stream and extraction liberates it from solid waste, purification works on material that is already mostly precious metal — crude doré, pre-cast anode plates, alloyed jewellery scrap, cemented powder, loaded eluate — and answers one question: what is left in it that should not be, and how is it taken out without losing metal in the process.

The distinction matters because purification is where refineries lose the most value, and rarely for a technical reason. It fails in three predictable ways. The first is route mismatch: an aqua regia line is chosen for feed that is mostly silver, where nitric parting or an electrolytic silver circuit is correct, or an electrolytic cell is asked to purify mixed 18-karat scrap that must first be inquarted to anode-grade. The second is assay indiscipline: batches run against estimated grades instead of a weighed, sampled, assayed feed, so electrolyte chemistry drifts, current efficiency falls and the operator cannot tell purity loss from weighing loss. The third is purity that is not held at the end of the line: metal is purified correctly in the cell, then re-contaminated in a dirty crucible, an oxidised mould or a wet powder that is charged before it is fully dry. A YuSai purification line is engineered against all three: the route is selected from the assay, the process parameters are set per batch against that assay, and the melting, casting and granulation stage is designed as part of the purification scope rather than as a separate afterthought.

Five technology pillars make up the line, and a project takes the ones its feed requires. Electrolytic purification dissolves a prepared anode under controlled direct current and deposits high-purity metal at the cathode — the standard route to 99.99% gold and silver, and the route that also collects the platinum group metals into the anode residue for separate treatment. Aqua regia and chemical purification dissolves mixed and alloyed feed in an acid-resistant titanium or borosilicate reactor, then removes impurities and recovers each metal by selective precipitation, cementation and reduction — the flexible route for feed that is not predominantly one metal. Solvent extraction and ion exchange separate the chemically similar platinum group metals from each other and from base-metal contaminants using P204, P507 and C272 systems, ion exchange resin and activated carbon. Melt refining handles the impurities that chemistry is poor at — lead, tin, antimony and bismuth are oxidised and taken into slag, silver is removed in the Miller process, and cupellation separates the last of the base metals from gold and silver. Vacuum degassing and protective-atmosphere melting remove dissolved gas and prevent re-oxidation between the last purification step and the cast bar, which is where 4N metal most often drops back to 3N.

Purification performance is stated on defined bases. Recovery is the metal balance of your own feed, not a property of the equipment. Purity is quoted together with the method that verified it — fire assay to ISO 11426 and ASTM E1335 for gold-bearing material, ICP-OES difference analysis to ISO 15093 for gold, platinum and palladium and ISO 15096 for silver, and fineness checked against the LBMA Good Delivery minimum. Batch records, metal balances and certificates are issued as a controlled set, so a buyer or a customs authority can reproduce the result rather than accept it.

Every project begins in the laboratory. We assay your sample by fire assay, XRF and wet chemical analysis, measure the impurity profile element by element, and run bench-scale dissolution, precipitation and deposition tests to establish which route suits the feed and what the mass balance will be. Equipment is configured against that test result, and the line is handed over only after it produces metal at the agreed specification on your own material.

At a glance

Product purity: Au 99.99% (99.999% optional) · Ag 99.99% · Pt/Pd ≥99.95% · Rh ≥99.90% · Cu 99.99%
Comprehensive recovery: 95%+ from qualified feed; >99% on the electrolytic purification route
Purification routes: electrolytic · aqua regia chemical · solvent extraction and ion exchange · melt refining (Miller and cupellation) · vacuum degassing
Impurities removed: Cu · Pb · Zn · Fe · Ni · Sn · Bi · Te · Se · Ag from gold · base metals from PGM · organic and refractory residual
Purification points: crude metal, anode plates, dissolution liquor, electrolyte and final melt
Verification: fire assay, XRF screening, ICP-OES difference analysis and spark OES, with a Certificate of Analysis per batch
Compliance in scope: closed acid fume capture, NOx scrubbing, wastewater neutralisation and zero-liquid-discharge option
Scope: modules, a single purification train, or a complete feed-to-certified-metal turnkey line

Application Scenarios

Purification equipment is installed wherever metal already in hand is worth more as certified fine metal than as crude material:

Precious metal refineries and mints — upgrading doré, crude bullion, cemented powder and recycled feedstock into certified fine gold and silver bars and granules, with in-house assay and casting under one scope.
Gold and silver jewellery manufacturers — purifying bench sweeps, polishing and buffing dust, floor sweeps, casting sprues, old inventory and returned jewellery back to fine metal for direct reuse in the alloying and casting shop.
Gold dealers, pawnbrokers and cash-for-gold operators — upgrading mixed-karat and dental gold into fine bullion, so value is realised at the refinery price rather than at a discount for unfined scrap.
E-waste and WEEE recycling plants — purifying the gold, silver and palladium concentrate produced by the plant’s own extraction stage into saleable fine metal, and recovering the palladium and platinum that a gold-only route leaves in the residue.
PCB and electronics manufacturers — purifying gold-bearing strip, etching and deplating residues and spent plating chemistry into metal that can be returned to the plating anode.
Copper, lead, zinc and nickel smelters — treating anode slime as a payable precious-metal stream: copper and selenium removed first, then silver by nitric parting or electrolysis, gold by chlorination or aqua regia, and the platinum group metals separated from the residual liquor.
Automotive and industrial catalyst recyclers — separating and purifying platinum, palladium and rhodium from spent converter and process catalyst concentrate, where the three metals must be split from each other and not merely collected.
Petrochemical and chemical plants — reclaiming precious metal from spent hydrogenation, reforming and coal-chemical catalysts, and from the refinery’s own residues and filter cake.
Dental laboratories and dental alloy processors — recovering and purifying gold and palladium from crowns, bridges, frameworks and machining swarf.
Photographic, imaging and X-ray processors — purifying recovered silver from fixing, bleaching and developing solutions up to electrolytic-grade fine silver.
Photovoltaic panel recyclers — purifying recovered silver from delaminated solar cells, bus bar offcuts and cell fragments.
Mining and metallurgical operations — final purification of doré and gravity concentrate on site, or at a satellite facility, instead of shipping unfined metal to a third-party refinery.
Assay laboratories, universities and research institutes — compact purification and fire assay units operating with the same documentation discipline as an industrial refinery.
Precious metal traders and scrap consolidators — a small in-house purification line that converts consolidated scrap into certified bars with a documented chain of custody.

Applicable Raw Materials

Feedstock is grouped by the impurity it carries, because the impurity profile — not the metal content — selects the purification route. The exact flowsheet for any individual stream is confirmed by laboratory test before equipment design is frozen.

Crude bullion and doré — mine doré bars, gravity and Merrill-Crowe precipitate, electrowinning sludge after drying and smelting, and crude bullion from smelting operations. Processed by melting and inquartation, then chemical dissolution or direct anode casting followed by electrolytic purification. Output: fine gold and silver at 99.99%, with the platinum group metals routed to their own separation circuit.

Pre-cast anode plates and anode scrap — gold and silver anode plates cast for electrolysis, gold anode scrap, silver anode remnants and spent anodes recovered from the cell. Processed by re-melting, re-alloying to the correct anode composition and re-casting, then electrolytic purification. Output: cathode gold and electrolytic silver crystal at 99.99% purity.

Mixed-karat and alloyed jewellery scrap — 8K to 24K gold alloys, silver alloys, white gold with nickel or palladium, rose gold with copper, dental gold and palladium alloys, and old jewellery with solder and base-metal components. Processed by sorting, stone and non-metal removal, weighing, inquartation with silver or copper and nitric parting, or by direct aqua regia dissolution. Output: fine gold and fine silver as powder, crystal or ingot, with palladium and platinum recovered from the parting liquor.

Bench sweeps, polishing dust and floor sweeps — jeweller’s bench sweep, buffing and polishing dust, lapping and grinding swarf, floor sweepings, vacuum bag content and tumbling waste. Processed by incineration or ashing, ash crushing and mixing, melting with flux, then the same chemical or electrolytic purification route as the resulting alloy. Output: fine gold and silver, with the ash residue re-assayed before release.

Anode slime and refinery residues — copper anode slime, lead and zinc anode slime, tank house slime and cell mud, refinery sweepings, silver chloride residue, cemented and precipitated intermediates and filter cake. Processed by washing, drying and roasting to remove copper and selenium, acid leaching, selective separation of silver, gold and the platinum group metals, and finally electrolytic purification. Output: fine gold and silver plus PGM liquor, and selenium and tellurium concentrates as payable by-products.

Spent catalysts and PGM-bearing materials — ceramic honeycomb and metallic substrate automotive catalysts, petrochemical, hydrogenation and reforming catalysts, fuel-cell catalyst, PGM alloy scrap, glass fibre refractory brick and glass cullet carrying platinum and rhodium, and spent electroplating and process residues. Processed by incineration or roasting, dissolution in chloride media, then solvent extraction, ion exchange, precipitation and cementation to separate and purify each metal. Output: platinum sponge, palladium powder or salt, rhodium powder or chloride solution and iridium at the purities the individual metals permit.

High-concentration process liquors and eluates — gold chloride and gold cyanide liquors, silver nitrate solution from nitric parting, PGM chloride liquor, ion exchange eluate, loaded activated carbon desorbate and spent electrolyte. Processed by filtration and impurity removal, selective precipitation or cementation, then electrolytic purification or reduction to metal. Output: fine metal powder or crystal, and regenerated electrolyte returned to the cell.

Intermediate and in-process streams — gold chloride solution after filtration, silver chloride precipitate, gold and silver powders from the precipitation stage, hydroxide and carbonate precipitates and off-spec product from earlier batches. Processed as in-circuit intermediates by re-dissolution, washing, reduction or re-melting, rather than released as waste. Output: pregnant liquor or semi-refined metal returned to the head of the purification train.

Feed qualification — what this line is not designed to process

Stated plainly, because it saves both parties time:

Mixed, uncharacterised feed with no assay and no impurity profile — no route can be selected and no responsible purity or recovery figure can be quoted.
Base-metal-dominant feed or heavily contaminated scrap sent straight to an electrolytic cell — the anode must be upgraded by melting, inquartation or chemical pre-treatment first.
High-grade silver and silver chloride feed sent directly to gold electrolysis — these require nitric parting or a dedicated silver circuit.
Feed containing mercury, thallium or high-concentration cyanide without a dedicated abatement module.
Material regulated as hazardous waste without the corresponding handling licence at the destination site.
Powder feed charged wet, or dry powder charged in an atmosphere that lets it re-oxidise before melting — purity is lost at this point and the loss is not recoverable downstream.

If your material falls outside these limits, tell us the composition and we will say so before a quotation is issued.

Output Products

The line delivers finished, saleable metal plus the intermediates the next stage of refining needs. Each entry states the form the product leaves the plant in, the purity it is released at, and the assay behind that figure.

Fine gold — supplied as ingot, bar, granule or electrolytic gold powder. Purity 99.99% (4N) as standard, with 99.999% (5N) achievable through a second electrolytic pass. Output: LBMA Good Delivery-grade bullion cast to the bar weights you specify, released against a Certificate of Analysis, with gold anode plates and doré handled as in-circuit intermediates.

Fine silver — supplied as electrolytic silver crystal, silver powder, granule or ingot at 99.99% purity. Output: silver crystal for industrial sale, or ingot for investment and industrial use, with silver cement, silver chloride and silver nitrate solution treated as in-circuit intermediates rather than as waste.

Platinum and palladium — supplied as platinum sponge or ingot and palladium powder, sponge or purified salt, at a minimum of 99.95% purity. Output: sponge and powder released against ICP-OES difference analysis, or the purified compound your downstream process requires.

Rhodium and the remaining platinum group metals — rhodium powder or rhodium chloride solution at 99.90% minimum, with iridium, ruthenium and osmium recovered as separate streams when the feed carries them in economic quantities. Output: powder released against ICP-OES verification, or the salt form required by the customer’s own process.

Fine copper — copper cathode, copper plate and copper powder at 99.99% purity (LME Grade A equivalent). Output: cathode and plate recovered from electrolyte purification duty as a saleable base-metal product requiring no further treatment.

Precious metal salts and compounds — silver nitrate, gold chloride, palladium chloride and other purified salts produced where the customer’s downstream process consumes compounds rather than metal. Output: solution or crystallised salt to the concentration and purity specified.

Melt-refined bullion and granulation product — Miller-process and cupellation-refined gold and silver, and granulated product for downstream alloying. Output: bar, ingot or granule of defined fineness, with slag and dross returned to smelting until they are below the economic recovery threshold.

Assayed by-products — selenium and tellurium concentrates from anode slime treatment, base metal salts recovered from bleed treatment, and barren slag and dewatered residue released only after assay. Output: secondary saleable products plus a residue certified as below the economic recovery threshold.

Treated liquid and recycled process water — clarified, neutralised and polished liquid with precious metal content reduced to parts-per-million levels. Output: water suitable for recirculation to the process, reuse as coolant or cleaner, or release to the wastewater plant, with a zero-liquid-discharge configuration where required.

Process Workflow

The flowsheet combines thermal, chemical, electrochemical and quality-control stages. Which stages a project includes depends on the feed and its impurity profile: a jewellery scrap project may use steps 1, 3, 4, 6 and 7, while an anode slime project will normally run all eight.

Steps 1 — Feed Assay and Route Selection. Incoming material is weighed, logged and sampled as a discrete batch. The sample is characterised by XRF screening and, where precious metal content is payable, by fire assay or wet chemical analysis, with the impurity profile measured element by element — copper, lead, zinc, iron, nickel, tin, antimony, bismuth, selenium, tellurium and the individual platinum group metals. The result selects the purification route and sets the batch recipe. Output: a homogenised, weighed, numbered batch with a representative assay, an impurity profile and a route decision on file.

Steps 2 — Melting, Inquartation and Anode Preparation. Feed is melted in an induction or fuel-fired furnace with flux, and base metal is oxidised into slag and removed. Alloyed and mixed-karat feed is inquarted with silver or copper to raise the base-metal content so it can be parted, and the melt is cast into anode plates of the correct composition, geometry and weight for the cell, or granulated where a chemical route follows. Slag is tapped, cooled and assayed before release. Output: anode plates at the specified composition and weight, granule for dissolution, and an assayed slag returned to smelting until barren.

Steps 3 — Chemical Dissolution and Impurity Removal. Prepared feed is dissolved in an acid-resistant reactor — a heated titanium tumbler where the duty demands it, borosilicate glass or PTFE-lined vessel where transparency and inertness matter. Gold and the platinum group metals are taken into solution through aqua regia or chlorination; silver is taken into solution through nitric acid or parted from gold by nitric parting; specific feeds use chloride, alkaline or cyanide chemistry. Nitrogen oxides and acid mist generated in the reaction are drawn under an enclosed hood into the scrubber. Insoluble silica, glass fibre, plastics and undissolved base-metal oxides are then separated by multi-stage filtration. Output: filtered pregnant liquor, and a leach residue that is washed, assayed and returned for re-treatment.

Steps 4 — Selective Separation and Precipitation. Dissolved metals are separated in sequence so that each reaches the purity its own purification stage requires. Base metals are removed by pH-controlled precipitation, cementation or ion exchange. Gold is reduced and precipitated with a controlled reducing agent. Silver is recovered as chloride, as cement or by nitric route. Platinum, palladium, rhodium and iridium are separated from each other by mixer-settler solvent extraction using P204, P507 and C272 systems, by ion exchange resin, and by selective precipitation and reduction against the individual metal chemistries. Output: separated metal liquors and purified intermediate compounds, each routed to its own purification or deposition stage.

Steps 5 — Electrolytic Purification. Purified anode plates are dissolved under controlled direct current in an electrolytic cell, and high-purity metal is deposited at the cathode. Gold is refined in Wohlwill-type cells with a chloride electrolyte; silver in Möbius-type cells with a nitrate electrolyte; base-metal duty uses Pb-Ca-Sn anodes and stainless or titanium cathodes. Anode bags with counter-current washing keep insoluble impurity and anode residue out of the cathode product, and the residue is collected as a separate precious-metal stream rather than lost to the electrolyte. Electrolyte is filtered, cooled and circulated continuously, with temperature held to ±1 °C, and current density, voltage, ORP and metal concentration are logged per batch. Output: high-purity cathode gold and electrolytic silver crystal, with anode residue routed to the platinum group metal circuit.

Steps 6 — Product Melting, Casting and Granulation. Purified metal is washed, dried to complete dryness, weighed and melted in a graphite or ceramic crucible in an induction furnace, in vacuum or under protective atmosphere where the fineness justifies it. Flux is added to collect the last of the impurity into a slag layer and to protect the melt from oxidation. Molten metal is cast into ingots, bars or anodes, atomised into powder, or poured through a granulator. Output: marked, weighed finished product and granule, with crucible and mould cleanliness controlled as a purity-critical step rather than a housekeeping one.

Steps 7 — Assay, Certification and Release. Every batch is re-assayed before release: fire assay to ISO 11426 or ASTM E1335 for gold-bearing material, ICP-OES difference analysis to ISO 15093 for gold, platinum and palladium and ISO 15096 for silver, XRF screening in process, and spark OES for solid alloy samples where the material and calibration are suitable. Fineness is checked against the LBMA Good Delivery minimum of 995.0 for gold and 999.0 for silver. The batch is released against a Certificate of Analysis naming the method used, together with a documented metal balance for custody transfer, customs and internal accounting. Output: certified finished product with a traceable assay record.

Steps 8 — Off-Gas, Wastewater and Metal Loss Recovery. This step runs continuously across steps 1 to 7 rather than sequentially after them. Acid fumes and nitrogen oxides released during dissolution, precipitation and electrolysis are captured under enclosed hoods and covers, condensed, and neutralised in a single- or multi-tower absorption scrubber using a circulating alkaline solution, with removal efficiency monitored against the local permit limit. Wastewater is neutralised to the discharge pH range, precipitated, flocculated, dewatered and polished by ion exchange, and clarified water is recirculated to the process or reused as coolant. Off-spec product, cell residues, filter cake, anode residue and slag return to the appropriate upstream stage instead of leaving as waste. Output: treated gas and water within the agreed limits, and metal losses closed back into the circuit.

Product Structure (Main Equipment)

The line is assembled from the following modules. Modules can be supplied individually for customers upgrading an existing refinery, or as a complete line with layout, utilities design, installation, commissioning and operator training.

Feed preparation and assay module — platform and bench scales, sampling and riffle splitting equipment, jaw crusher and pulveriser, XRF analyser, and a laboratory sample register and weighing station.

Melting and anode preparation module — induction melting furnace with graphite or ceramic crucible, fuel-fired or electric melting furnace, ingot and anode moulds, anode casting table, slag skimming tools, and ingot trolley and pouring cart.

Inquartation and parting module — inquartation reactor, nitric acid boiling apparatus with condenser, parting and washing vessels, and granule and shot preparation equipment.

Chemical dissolution module — heated titanium tumbler reactor, borosilicate glass 3.3 or PTFE-lined reaction vessel, dissolution and precipitation kettles, acid and reagent dosing station with metering pumps, and a transparent or enclosed reactor hood.

Solid-liquid separation module — wheeled vacuum filter units, filter press, cartridge and precision filtration, decanter centrifuge, multi-layer washing and sedimentation tanks, and clear-liquor storage tanks.

Impurity removal and separation module — precipitation and pH-control reactors, cementation tanks, ion exchange resin columns, activated carbon adsorption columns, and mixer-settler solvent extraction banks configured for P204, P507 and C272 duty.

Electrolytic purification module — electrolytic cells in PPH, PP, PVC- or PVDF-lined steel, Wohlwill-type gold cells and Möbius-type silver cells, titanium cathode plates and starter sheets, MMO-coated titanium anodes and Pb-Ca-Sn anodes, anode bags and diaphragms in acid-resistant fabric or PTFE with counter-current wash, titanium-clad copper conductive bars and bus bars, electrolyte circulation, filtration and cooling, and stripping and rinsing stations.

Power and rectifier module — high-frequency switching rectifiers and IGBT rectifiers with automatic pole reversing, DC bus distribution, current-density control, and cell voltage and current monitoring per tank.

Environmental control module — enclosed hoods and covers, transparent closed flue-gas cover plates, flue-gas condensation system, single- or multi-tower absorption scrubber for nitrogen oxides and acid gas, cyclone and plenum-chamber gas washing, mist eliminator, exhaust fan, and stack with monitoring ports.

Wastewater module — neutralisation and precipitation tank, flocculation and sedimentation, filter press for sludge, ion exchange polishing, pH and ORP control, and a recirculation or zero-liquid-discharge circuit.

Melting, casting and granulation module — induction melting furnace with vacuum or protective-atmosphere option, granulation unit, ingot and bar moulds, mould stands, vacuum casting unit, and powder atomisation unit where required.

Quality control laboratory module — fire assay muffle and cupellation furnace, assay crucibles and cupels, high-readability analytical balance, precision density balance, XRF analyser, benchtop or spark OES where specified, touchstone and test needles for preliminary screening, electronic gold tester, ultrasonic cleaner, desiccator, drying and washing centrifuge, and a controlled sample storage and record system.

Control and automation module — PLC and SCADA control cabinet with recipe management per feed type, logging of temperature, pH, ORP, conductivity, flow, current density and level, alarm management, batch traceability, and remote monitoring access.

Product Features

Route selected from the impurity profile — the flowsheet is chosen against the element-by-element assay of your own sample, so mixed and alloyed feed is engineered for rather than rejected.
Electrolytic purification to 99.99% — Wohlwill-type gold cells and Möbius-type silver cells from pre-cast anode plates, with anode residue collected as a separate precious-metal stream instead of being lost to the electrolyte.
Aqua regia chemical route for mixed feed — a heated titanium tumbler or borosilicate glass reactor with metered acid dosing, for feed that is not predominantly one metal.
Platinum group metal separation in scope — mixer-settler solvent extraction with P204, P507 and C272 systems, ion exchange resin and selective precipitation split platinum, palladium, rhodium and iridium from each other, not merely from base metal.
Melt refining for chemistry-resistant impurities — lead, tin, antimony and bismuth oxidised into slag and silver removed by the Miller process, with cupellation for the final separation.
Vacuum and protective-atmosphere casting — dissolved gas removed and re-oxidation prevented between the last purification step and the cast bar, which is where 4N metal most often drops back to 3N.
Purification held through to the cast product — crucible and mould cleanliness, powder dryness and melt atmosphere are treated as purity-critical parameters, not housekeeping.
On-site quality control laboratory — fire assay, cupellation, analytical balance, XRF and ICP-OES support in the same scope, so the refinery certifies its own batches rather than depending on an outside laboratory.
Purity claims carry the assay method — every figure is stated against ISO 11426, ASTM E1335, ISO 15093 or ISO 15096 and checked against the LBMA Good Delivery minimum, so a buyer or customs authority can reproduce it.
Documented metal balance per batch — weighing, sampling and assay points at every stage produce a traceable balance for custody transfer, customs documentation and internal accounting.
Closed environmental control — enclosed hoods, flue-gas condensation, single- or multi-tower NOx and acid-gas absorption, and a wastewater circuit with zero-liquid-discharge capability, engineered with the process rather than procured afterwards.
Corrosion-resistant construction throughout — PPH, PP, FRP, PVDF, PTFE-lined steel, borosilicate glass 3.3 and titanium in wetted service, sized for the actual acid and chloride duty.
Automatic intelligent control — PLC and SCADA with per-feed recipes, metered reagent dosing, temperature control to ±1 °C in the cells, and remote monitoring, so the line runs without a dedicated metallurgist on every shift.
Metal losses recycled, not written off — off-spec product, anode residue, filter cake, slag and dross re-enter the circuit instead of leaving as waste.
Modular and scalable — additional cells, columns, extraction stages or refining modules connect through standardised interfaces, so capacity and capability are added rather than replaced.
Audit-ready documentation — operating manual, maintenance manual, P&ID, electrical drawings, instrumentation list, spare parts list, material certificates, batch records and certificates of analysis supplied as a controlled set.

Technical Parameters And Specifications

Values below are the standard design basis. Final parameters are fixed during process design, after the customer’s feedstock and impurity profile have been assayed. Parameters marked * are confirmed per project.

1. System Scope And Purification Route

Parameter	Specification
Target metals	Gold (Au), Silver (Ag), Platinum (Pt), Palladium (Pd), Rhodium (Rh), Iridium (Ir); Copper (Cu) as a parallel product; Ru, Os, Se, Te on request *
Primary function	Removal of residual impurities from concentrated precious-metal feed and upgrading to a defined fine-metal fineness
Feed condition accepted	Crude doré and bullion, pre-cast anode plates, mixed-karat and alloyed scrap, sweeps and ash, anode slime, spent catalyst concentrate, process liquor and eluate, cemented and precipitated powder *
Purification routes available	Electrolytic purification · aqua regia and chloride chemical purification · nitric parting and inquartation · solvent extraction and ion exchange · melt refining (Miller and cupellation) · vacuum degassing and protective-atmosphere melting *
Route selection basis	Element-by-element assay and impurity profile of the customer’s own sample, confirmed by bench-scale test
Impurities handled	Cu, Pb, Zn, Fe, Ni, Sn, Sb, Bi, As, Se, Te, Ag from gold-bearing feed, base metals and individual PGMs from each other, organic and refractory residue
Operating mode	Batch or continuous *
Scope of supply	Single module, purification train, or complete feed-to-certified-metal turnkey line *
Automation level	Manual, semi-automatic or fully automatic with PLC and SCADA recipe control *

2. Feed And Product Parameters

Parameter	Value	Basis
Comprehensive recovery rate	≥ 95%	Multi-metal feedstock, calculated per project from the batch metal balance
Recovery rate, electrolytic purification route	> 99%	High-concentration gold, silver and palladium feed *
Recovery rate, anode slime route	97–98% typical, up to > 99%	Gold and silver from copper and lead anode slime
Anode residue recovery	Closed loop	Insoluble precious metal collected from anode bags and returned to the separation circuit
Minimum economic feed grade	Set per project	Feed below the threshold is quoted as a route comparison rather than as a recovery guarantee *
Recovery calculation basis	(metal in feed − metal in final slag − metal in residue − metal in effluent) ÷ metal in feed	Stated in the proposal so it can be checked against your own assays *

3. Product Purity Parameters

Product	Purity	Form	Verification method
Fine gold	99.99% (4N) standard; 99.999% (5N) on a second electrolytic pass	Ingot, bar, granule, electrolytic powder	Fire assay, then ICP-OES difference analysis
Fine silver	99.99%	Electrolytic crystal, powder, granule, ingot	Fire assay, then ICP-OES difference analysis
Platinum	≥ 99.95%	Sponge, ingot	ICP-OES difference analysis
Palladium	≥ 99.95%	Powder, sponge, purified salt	ICP-OES difference analysis
Rhodium	≥ 99.90%	Powder, chloride solution	ICP-OES difference analysis
Iridium, ruthenium, osmium	Per project	Powder, sponge, salt	ICP-OES difference analysis
Fine copper	99.99% (LME Grade A equivalent)	Cathode, plate, powder	Electrolytic assay per batch
Gold stripped from the cathode in the first pass	95–99.8%	Plate, crystal or powder for re-melting	XRF screening, fire assay
Residual metal in treated liquid	Silver below 5–20 ppm; gold below 2–10 ppm *	Clarified or polished liquid for reuse or discharge	ICP-OES or AAS per batch

4. Purification And Process Parameters

Parameter	Specification
Cell body material	PPH, PP, FRP, PVDF or PVC-lined steel; concrete or FRP shell for large cells *
Cathode	Titanium cathode plate or sheet; starter sheet; stainless steel for base-metal duty *
Anode material	Cast precious-metal anode plate; MMO-coated titanium anode; Pb-Ca-Sn anode for base-metal duty; graphite where required *
Conductive bar and bus bar	Titanium-clad copper
Anode containment	Anode bag or diaphragm in acid-resistant fabric or PTFE, with counter-current wash circuit
Rectifier and power supply	High-frequency switching or IGBT rectifier with automatic pole reversing
Cathode current density	Up to 1000–1200 A/m² for gold electrolysis; 300–800 A/m² for silver electrolysis *
Electrolyte temperature	Gold electrolyte 60–70 °C; silver electrolyte controlled at ≤ 50 °C via cooling circuit *
Temperature control accuracy	± 1 °C in electrolytic purification cells
Electrolyte circulation	Closed loop with continuous filtration and conductivity monitoring
Dissolution reactor	Heated titanium tumbler; borosilicate glass 3.3 vessel; PTFE-lined reactor *
Dissolution chemistry	Aqua regia and chlorination for gold and PGM; nitric acid and nitric parting for silver; chloride, alkaline and cyanide media for specific feeds *
Separation chemistry	Solvent extraction with P204 / P507 / C272, ion exchange resin, activated carbon adsorption, selective precipitation, cementation, reduction
Melt refining	Fluxed melting and slagging; Miller process for silver removal; cupellation for the final base-metal separation *
Casting atmosphere	Air, protective gas or vacuum *
Reagent handling	Metered dosing with acid-resistant pumps, enclosed storage and bunded reagent area

5. Quality Control And Assay Parameters

Stage	Method	Reference standard
Feed sampling and assay	Representative sampling by riffle splitting, XRF screening, fire assay or wet chemical analysis	ISO 11426, ASTM E1335
Impurity profile	Element-by-element analysis of base metals, PGMs, selenium and tellurium	Per project
In-process control	Titration, ORP, pH and specific-ion measurement	Per project
High-purity gold, platinum, palladium	Difference method by ICP-OES	ISO 15093
High-purity silver	Difference method by ICP-OES	ISO 15096
Solid alloy samples	Spark OES where material and calibration are suitable	Per laboratory procedure
Preliminary screening	XRF, touchstone and density measurement	Per laboratory procedure
Final product release	Fire assay to 999.5‰, or ICP-OES difference above that fineness	ISO 11426, ISO 15093, ISO 15096
Good Delivery compliance	Fineness against LBMA Good Delivery minimum (995.0 gold, 999.0 silver)	LBMA Good Delivery Rules
Batch documentation	Certificate of Analysis naming the method used, plus a documented metal balance	Issued per batch

6.Materials Of Construction

Stream or equipment	Material options
Dissolution and reaction vessels	High-resistance titanium tumbler, borosilicate glass 3.3 (Duran / Pyrex type), PTFE-lined, PPH, enamel-lined steel
Acid, chloride and nitrate tanks	PPH, PVC, PVDF, FRP
Electrolytic cell bodies	PPH, PP, PVC-lined steel, PTFE or PVDF-lined
Wetted parts, pumps and fittings	PTFE, PVDF, titanium, borosilicate glass, 316L stainless steel
Cathode and anode substrates	Titanium, stainless steel, graphite, MMO-coated titanium, precious-metal coated
Off-gas ducting, scrubber and cyclone	PPH, FRP, PVC, PP
Filter media and membranes	Polypropylene membrane, ceramic filter, acid-resistant filter cloth
Crucibles and moulds	High-purity graphite, ceramic, cast iron and steel moulds

7. Control, Utilities And Environmental Parameters

Parameter	Specification
Control system	PLC + SCADA with automatic intelligent control, per-feed recipe management and remote monitoring
Instrumentation	Temperature, pH, ORP, conductivity, flow, current density, cell voltage, level
Reagent dosing	Metered pump dosing for acid and reagents, with automatic cut-off on alarm
Data logging	Batch-based recording of process parameters, reagent additions and metal balance
Air emission control	Enclosed hoods + flue-gas condensation + single- or multi-tower absorption scrubber; removal efficiency above 99% and outlet concentration set to the local permit limit *
Wastewater treatment	Neutralisation to the discharge pH range, precipitation, flocculation, sludge dewatering, ion exchange polishing; recirculation with zero-liquid-discharge option
Power supply	380 V / 415 V / 440 V, 50 Hz or 60 Hz, three-phase; configured to the local grid and standard *
Utilities	Process water, cooling water, compressed air, exhaust ventilation; steam only for stages requiring elevated temperature
Capacity basis	Defined per project as batch mass × cycles per day from your feed grade, impurity profile and target output; scaled by module count rather than by a single fixed model size *
Installation form	Modular skid-mounted or site-assembled, with CAD / 3D plant layout and utility schedule provided
Site requirements	Bunded reagent storage, acid-resistant flooring and drainage, controlled ventilation, and space for the QC laboratory *

Important. Precious metal purification involves strong acids, chlorine gas, nitrogen oxides and molten metal. Do not scale or operate a process from published text alone. Final design must be validated by our engineers against your specific feed, local regulations and site conditions.

Technical Advantages

The route is chosen to fit the feed, not the feed to fit the route. Most suppliers sell either an electrolytic cell or a chemical plant, and a buyer whose feed does not suit that one route is told to pre-treat it elsewhere. YuSai designs across all five purification pillars — electrolytic, chemical, solvent extraction, melt refining and protective-atmosphere casting — so a mixed-karat jewellery stream, an anode slime residue and a PGM catalyst concentrate can each be routed to the method that actually removes their impurities rather than to the method the supplier happens to build.

Purity is held all the way to the cast bar. The most common reason a refinery with a working electrolytic cell still ships 3N metal is contamination after purification: a dirty crucible, an oxidised mould, wet powder charged into the melt, or a bar that re-oxidises on cooling. In this line the melting, casting and granulation stage is inside the purification scope, with vacuum or protective-atmosphere options and crucible and mould cleanliness treated as purity-critical parameters.

Nothing valuable leaves in the anode bag. Insoluble impurity and residual precious metal collect in the anode bag and diaphragm during electrolysis, and with counter-current washing the residue is recovered as a payable stream rather than being discarded with the bag. The refining residue is where a bypassed recovery loop quietly costs a refinery more than its electrolyte bill.

Purity claims come with the method attached. Every figure is stated with the standard that verified it — ISO 11426 and ASTM E1335 for fire assay, ISO 15093 for gold, platinum and palladium by ICP-OES difference, ISO 15096 for silver — and checked against the LBMA Good Delivery minimum. When the buyer assays the bar on arrival, or a customs authority asks how the fineness was determined, the answer is already in the batch record.

Recovery is stated on a defined basis. We publish the metal-balance formula behind every recovery figure, so the number can be checked against your own assays instead of accepted on trust. Most listings in this category assert a percentage with no basis at all.

The platinum group metals are separated, not collected. Palladium, platinum, rhodium and iridium are chemically similar and the separation, not the dissolution, is the hard part. Mixer-settler solvent extraction with P204, P507 and C272 systems, ion exchange resin and selective precipitation are part of the standard scope, so the PGM content is realised as separate purified metals rather than as a mixed concentrate sold at a discount.

Impurities that chemistry handles poorly are handled thermally. Lead, tin, antimony and bismuth resist selective leaching and pass through electrolysis into the cathode product if they are not removed first. Fluxed melting with slagging, the Miller process for silver and cupellation for the final base-metal separation remove them before the electrochemical stage.

Assay capability sits inside the scope of supply. A fire assay muffle and cupellation furnace, a high-readability analytical balance, XRF and, where specified, ICP-OES and spark OES allow the refinery to characterise its own feed and certify its own batches. A refinery that depends on an outside laboratory for every assay cannot close a metal balance per batch, and cannot verify a purity claim in time to act on it.

Environmental compliance is engineered with the process. Acid fume capture, flue-gas condensation, single- or multi-tower NOx and acid-gas scrubbing, wastewater neutralisation and zero-liquid-discharge capability are designed as part of the flowsheet, with defined performance targets rather than procured afterwards from a third party. This is normally the single largest cause of permitting delay on a purification project.

Losses are recycled, not written off. Off-spec product, anode residue, filter cake, slag and dross re-enter the circuit instead of leaving as waste, which raises effective yield without buying a gram of additional feed.

Design is based on your sample, not a catalogue. Route selection and equipment sizing are driven by assay and bench-scale test results, so the customer sees the expected mass balance, the reagent consumption and the metal tied up in in-process inventory before signing.

Feed disqualification is stated up front. Saying what the line cannot process protects the project schedule and the commercial relationship, and it is the information buyers look for after a poor experience elsewhere.

Documentation is audit-ready. P&IDs, instrumentation lists, procedures, batch records, metal balances and certificates are supplied as a controlled set, so quality-system audits, customer claims and customs enquiries do not require reconstruction.

Service Flow

Inquiry and Process Consultation — share your feedstock or process stream, its current handling route, the impurities you are trying to remove and your target metal and fineness. We respond with a preliminary purification route and the sample quantity and information required for testing.
Raw Material Testing and Assay — we analyse your sample by fire assay, XRF and wet chemical analysis, measure the impurity profile element by element, and run bench-scale dissolution, precipitation and deposition tests. We then issue a test report stating recoverable metal content, expected recovery, achievable fineness and the proposed purification sequence.
Process Design and Flowsheet — based on the test report we prepare a process flow diagram, mass balance, reagent and utility schedule, equipment list and a CAD or 3D plant layout matched to your site, including the position of the QC laboratory and the reagent storage and bunding arrangement.
Quotation and Contract — a detailed commercial proposal covering equipment scope, spares, documentation, shipping terms and service scope, with the lead time stated as a commitment rather than an estimate.
Detailed Engineering — P&IDs, equipment specifications, electrical and control design, plant layout, and the emission and effluent data needed to support your permit applications.
Manufacturing and Factory Acceptance Test — fabrication follows the approved drawings and materials specification. Key equipment is assembled and tested at the factory, and a factory acceptance test report with photographs and video is issued before shipment.
Packing, Shipping and Documentation — equipment is export-packed and container-loaded with a full shipping document set, including packing list, certificate of origin and the technical documentation package.
Site Installation — our engineers attend site to supervise mechanical erection, electrical and piping connection, water and gas commissioning and trial production.
Commissioning and Metal Balance Verification — cold and hot commissioning, tuning of process parameters on your actual feed, and verification of the batch metal balance and the achieved fineness. The line is handed over only after it produces metal at the agreed specification.
Operator Training and Handover — operating and maintenance personnel are trained on process control, reagent handling and safety, sampling and assay routines, crucible and mould handling, casting and granulation, and daily maintenance. Written manuals and video guides are supplied.
After-Sales Support — remote and on-site technical support, spare parts supply, periodic service visits, process optimisation and upgrade or retrofit service for the operating life of the line.

Warranty And After-Sales

Warranty. Equipment supplied by YuSai Machinery carries a standard warranty period from the date of commissioning or shipment, covering defects in materials and workmanship under normal operating conditions. Wear parts, consumable electrodes, anode bags and diaphragms, filter cloth, resin and carbon charges, crucibles and moulds, reagents and glassware, refractory lining, and items damaged by improper operation or unauthorised modification are excluded and are listed with their expected service life in the spare parts schedule. The exact warranty period is confirmed in the contract for each project.

Spare parts. Critical spares — cathode assemblies and electrode plates, anode bags and diaphragms, crucibles, moulds, gaskets, seals, pump components, filter media, glassware and rectifier modules — are quoted with the original order and can be supplied afterwards at cost-based pricing. A recommended first-year spare parts list is issued with the technical documentation, and critical spares remain available for the operating life of the line.

Technical support. Online technical support is available on a continuous basis, with remote diagnosis of control system data where the plant is connected. Where a fault cannot be resolved remotely, our engineers can attend site under the terms of the service agreement.

Installation and training. Site installation supervision, commissioning, metal balance verification and operator training are part of the standard delivery scope. Follow-up training visits and refresher sessions can be scheduled after the line has been running in production, and assay-method training is available for customers who intend to certify their own batches.

Process optimisation and upgrades. Because the line is modular, stages can be added or modified later — extra purification cells, additional resin or carbon columns, an added solvent extraction stage for a PGM circuit, automatic cathode handling, vacuum casting, or an upgrade of the control system. We also carry out process reviews based on the customer’s own operating data and assay records when the feed mix changes.

Documentation. Each project is delivered with an operating manual, maintenance manual, electrical drawings, P&ID, instrumentation list, spare parts list, material certificates, batch record templates and a commissioning report, in a format suitable for local regulatory inspection.

Frequently Asked Questions

What is precious metal purification equipment?
Precious metal purification equipment is the stage of a refinery that removes the impurities still carried by concentrated precious-metal feed and lifts it to a defined, saleable fineness. It works on material that is already mostly precious metal — crude doré, pre-cast anode plates, alloyed jewellery scrap, cemented powder or loaded eluate — and normally combines electrolytic purification, chemical dissolution and selective precipitation, solvent extraction and ion exchange, melt refining, and melting and casting under protective atmosphere, together with the off-gas and wastewater treatment that make the line licensable.

What is the difference between purification, recovery, extraction and refining?
Recovery is the capture step: pulling metal out of a stream such as plating waste, rinse water or effluent that would otherwise lose it. Extraction is the liberation step: breaking down solid feedstock such as circuit boards, anode slime or spent catalysts so the metal can be dissolved and separated. Purification starts later, on feed that is already concentrated, and removes the remaining impurities element by element. Refining is the general term that covers the whole sequence including melting and casting to a certified product. The four are often sold as one system, but they are different process stages with different design drivers.

Which precious metals can this equipment purify?
Gold, silver, platinum, palladium and rhodium are the primary metals, with copper recovered in parallel as a cathode product and iridium, ruthenium, osmium, selenium and tellurium included in the flowsheet when the feed carries them in economic quantities.

What purity can the finished metal reach?
Gold and silver are purified to 99.99% (4N) as standard, and gold can reach 99.999% (5N) through a second electrolytic pass. Platinum and palladium are delivered at a minimum of 99.95%, rhodium at a minimum of 99.90%, and fine copper cathode at 99.99%. Gold stripped directly from the cathode in the first pass is produced at 95–99.8% purity and is then refined further.

Which purification route is right for my material?
It depends on the impurity profile rather than on the metal content. Electrolytic purification suits feed that can be cast into an anode plate at or near the required composition, and it is the standard route to 99.99% gold and silver. Aqua regia and other chemical dissolution routes suit mixed-karat and alloyed scrap, sweeps and ash, and feed that is not predominantly one metal. Nitric parting or a dedicated silver circuit is correct where silver is the dominant metal. Solvent extraction and ion exchange are required where platinum, palladium, rhodium and iridium have to be separated from each other. Melt refining is used where lead, tin, antimony or bismuth must be removed before the electrochemical stage. The proposal includes a route-selection comparison for your material.

How do I know whether my material can be purified on this line?
Send a representative sample. We analyse it by fire assay, XRF and wet chemical analysis, measure the impurity profile element by element, and run bench-scale dissolution, precipitation and deposition tests. You receive a test report stating the recoverable metal content, the expected recovery, the achievable fineness and the proposed purification sequence. Equipment design is based on that test report rather than on assumptions.

Which materials can the line not process?
Mixed feed with no assay and no impurity profile, base-metal-dominant scrap sent straight to an electrolytic cell without an upgrading step, high-grade silver and silver chloride sent directly to gold electrolysis, feed containing mercury, thallium or high-concentration cyanide without a dedicated abatement module, and hazardous waste without the corresponding handling licence at the destination site. We will tell you before quoting if your material falls into one of these categories.

What is the recovery rate?
The standard design target is 95% or higher comprehensive recovery on multi-metal feedstock, and the electrolytic purification route achieves more than 99% recovery on high-concentration gold, silver and palladium feed. On the anode slime route, gold and silver recovery of 97–98% is typical and can exceed 99%. Actual recovery depends on the grade and matrix of the feedstock and is confirmed by the raw material test.

How is the recovery figure calculated?
Recovery is the metal balance of your specific feed, calculated as metal in feed minus metal in final slag, residue and effluent, divided by metal in feed. Two refineries with identical equipment and different feed will report different recoveries, so we state the basis rather than only the number, and you can check it against your own assays.

Why does purified metal sometimes come out lower than 4N?
Purity is usually lost after the purification step rather than during it. The common causes are a dirty or previously used crucible, an oxidised or inadequately coated mould, wet powder charged into the melt, a melt left open to the atmosphere, and metal poured over a floor or surface that carries base-metal dust. Contamination can also come from earlier in the line where anode bag integrity, electrolyte filtration or reagent quality is not controlled. These are treated as purity-critical parameters in the design, and the melting and casting stage is specified as part of the purification scope for that reason.

How is the purity figure verified?
Fire assay to ISO 11426 or ASTM E1335 for gold-bearing material, XRF screening in process, spark OES for solid alloy samples where the material and calibration are suitable, and ICP-OES difference analysis to ISO 15093 for gold, platinum and palladium and ISO 15096 for silver. Fineness is checked against the LBMA Good Delivery minimum. Every batch is released with a Certificate of Analysis naming the method used, so a third-party laboratory can reproduce the result.

What is the difference between fire assay and XRF?
Fire assay is a destructive preparation and separation method that gives a quantitative determination of gold and silver in ores, concentrates, bullion and refinery samples, and it remains the reference method for high-confidence determination. XRF is a rapid, non-destructive elemental screening method for suitable solid samples, and its result depends on calibration, sample homogeneity, surface condition and matrix. The two serve different purposes, which is why a purification line uses XRF for screening and fire assay or ICP-OES for release.

Can an XRF analyser replace fire assay for final certification?
Not where a quantitative, high-confidence determination is required. XRF is valuable for rapid screening, alloy identification, sorting and process checks, but the release of a fine-metal batch is normally supported by fire assay or ICP-OES. Laboratories frequently keep both because screening and certification have different analytical requirements.

Do I need both a purification line and a laboratory?
You can operate without a laboratory, but you cannot then certify your own batches, close a metal balance per batch or react to a drifting electrolyte before a batch is lost. A fire assay furnace, a high-readability balance and an XRF analyser are the minimum practical set. ICP-OES and spark OES are added where the refinery needs to verify high-purity metal by difference analysis or to measure impurity elements at low concentration.

What equipment is required in addition to the purification cells?
A practical line normally includes feed preparation and sampling equipment, melting and anode casting, dissolution and reaction vessels with metered reagent dosing, filtration and solid-liquid separation, ion exchange or solvent extraction, electrolyte circulation, filtration and cooling, the rectifier and bus bar system, melting, casting and granulation, acid fume and NOx scrubbing, wastewater neutralisation, and the quality control laboratory. Confirm the exact scope in the quotation rather than comparing only the cell or the rated capacity.

How does the electrolytic purification step work?
A prepared anode plate is dissolved under controlled direct current in an electrolyte held at a defined temperature and composition. Precious metal dissolves from the anode and deposits at the cathode in high-purity form. Less-soluble impurity and residual precious metal collect in the anode bag or as cell residue, while soluble impurities remain controlled by electrolyte composition and bleed. Gold is refined in Wohlwill-type chloride cells, silver in Möbius-type nitrate cells, and electrolyte is filtered, cooled and circulated continuously, with current density, voltage, temperature and metal concentration logged per batch.

How are platinum, palladium and rhodium separated from each other?
They are separated in solution, not as metals. After dissolution in chloride media, the metals are split using mixer-settler solvent extraction with P204, P507 and C272 systems, ion exchange resin, and selective precipitation and reduction selected against the chemistry of each individual metal. This separation is the hardest part of a PGM circuit and is the reason a mixed PGM concentrate is worth less than the separate purified metals.

Why is melt refining needed if chemical purification already works?
Some impurities resist selective leaching and pass into the cathode product if they are not removed first — lead, tin, antimony and bismuth are the common examples, and silver interferes with gold electrolysis above a certain level. Fluxed melting with slagging oxidises and removes them, the Miller process removes silver by chlorination, and cupellation separates the last of the base metals from gold and silver. Melt refining and chemical purification are complementary rather than alternatives.

What metal concentration is left in the treated liquid?
On the electrolytic purification route, treated liquid is typically reduced to below 5–20 ppm silver and below 2–10 ppm gold, with ion exchange or activated carbon polishing applied where lower residual levels are required. The target figure for each project is fixed during process design against your discharge standard.

How is nitrogen oxide and acid gas handled?
Dissolution and electrolysis are carried out under enclosed hoods and covers. Fumes pass through a flue-gas condensation system and then a single- or multi-tower absorption scrubber with a circulating alkaline solution before discharge, with removal efficiency above 99% and the outlet concentration set to match the local permit limit. Cyclone and plenum-chamber washing, mist elimination and an acid-resistant exhaust fan complete the train.

Can the line run with no liquid discharge?
Yes. Process water is recirculated, and the bleed stream passes through neutralisation, precipitation, flocculation and ion exchange polishing. Clarified water is reused as process water, coolant or cleaner, and a zero-liquid-discharge configuration is available where local regulations or site constraints require it.

Is the equipment suitable for small workshops and laboratories?
Yes. Compact purification and fire assay units are available for laboratories, assay offices, jewellery workshops and small plating lines, and they use the same cell, reactor and control architecture as the industrial line. This allows a process to be validated on a small scale before investment is expanded, which is the normal route for a first in-house refining capability.

Can the line be installed inside an existing refinery or production building?
Yes. Modules are skid-mounted or site-assembled and are laid out against your actual building or yard dimensions, with multi-level arrangements used where floor area is limited. Reagent storage and bunding, acid-resistant flooring and drainage, and controlled ventilation are the main site requirements to plan for alongside the equipment.

What power supply and utilities are required?
The electrical design is configured to your site: 380 V, 415 V or 440 V, 50 Hz or 60 Hz, three-phase. Process water, cooling water, compressed air and exhaust ventilation are the main utilities, with steam required only for stages that need elevated temperature.

How much does precious metal purification equipment cost?
Cost is driven by the feedstock and impurity profile, the number of process stages, the degree of automation, the environmental modules required and whether a quality control laboratory is included, so a quotation is prepared after the raw material test rather than from a fixed list price. Modular construction allows a project to be implemented in phases, starting with the stream that causes the greatest metal loss or the greatest discount on the metal you are currently selling.

What is the return on investment on an in-house purification line?
The economics come from four places: the refining and assay fees no longer paid to a third party, the metal content that stopped being discounted as unfined scrap, the faster turnaround between scrap and saleable bar, and the higher price that certified fine metal commands over unrefined material. The payback period depends on the volume and grade of your feed, so it is modelled per project against your own figures rather than quoted as a standard number.

What do I need to send for a quotation?
A representative feed sample — typically a few kilograms, or a few litres for a solution stream — plus an existing assay report if you have one, your target metal and fineness, your expected batch size, and your site conditions including available power, floor space, ventilation and drainage. The assay and impurity profile are the single input that determines route, recovery projection, equipment list and price. Sampling and the feed assay are returned with the proposal.

How long is delivery and commissioning?
Standard modules and single units ship first; complete turnkey lines take longer because engineering is done against your assay and impurity profile. Installation and commissioning add site time depending on scope. Firm lead times are stated in the quotation.

What environmental approvals will I need?
Typically air emission approval for acid fumes and nitrogen oxides, effluent discharge consent for process water, and hazardous waste handling registration for acid residues, sludge and residues. We supply the emission and effluent data needed to support your local permit application.