EP1259652A4 - Process and apparatus for recovery of cyanide and metals - Google Patents
Process and apparatus for recovery of cyanide and metalsInfo
- Publication number
- EP1259652A4 EP1259652A4 EP01907238A EP01907238A EP1259652A4 EP 1259652 A4 EP1259652 A4 EP 1259652A4 EP 01907238 A EP01907238 A EP 01907238A EP 01907238 A EP01907238 A EP 01907238A EP 1259652 A4 EP1259652 A4 EP 1259652A4
- Authority
- EP
- European Patent Office
- Prior art keywords
- cyanide
- cell
- electrochemical
- metal
- complex
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/04—Obtaining noble metals by wet processes
- C22B11/042—Recovery of noble metals from waste materials
- C22B11/046—Recovery of noble metals from waste materials from manufactured products, e.g. from printed circuit boards, from photographic films, paper or baths
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/08—Obtaining noble metals by cyaniding
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C5/00—Electrolytic production, recovery or refining of metal powders or porous metal masses
- C25C5/02—Electrolytic production, recovery or refining of metal powders or porous metal masses from solutions
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/467—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/467—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction
- C02F1/4676—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction by electroreduction
- C02F1/4678—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction by electroreduction of metals
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/16—Nitrogen compounds, e.g. ammonia
- C02F2101/18—Cyanides
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/20—Heavy metals or heavy metal compounds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
- C02F2201/4611—Fluid flow
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
- C02F2201/4618—Supplying or removing reactants or electrolyte
- C02F2201/46185—Recycling the cathodic or anodic feed
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2301/00—General aspects of water treatment
- C02F2301/02—Fluid flow conditions
- C02F2301/024—Turbulent
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- the invention relates to processes and apparatus for recovery of cyanide and/or metals.
- the processes and apparatus may involve electrochemical and membrane processes.
- An electrochemical cell useful in such processes forms a further aspect of the invention.
- Cyanide is used extensively in gold processing plants for the leaching of gold from a milled ore containing it. Certain ores, concentrates and oxidation residues also contain copper and/or other base or precious metals that, like gold and silver, form complexes with cyanide. As a result, mixtures of dissolved complexes, including Cu(CN) 2 ' , Cu(CN) 3 2" and Cu(CN) 4 3' may also be formed in a gold cyanide leach solution.
- Oxidation may be used to destroy cyanide species known as weak acid dissociable cyanide from waste waters. Such oxidation techniques commonly involve use of an oxidant to destroy cyanide. Hydrogen peroxide has been widely used for this purpose with weak acid dissociable cyanide being oxidised to cyanide. Any metal ions released during the oxidation are precipitated, in an alkaline environment, as hydroxide. However, ferricyanide is not destroyed during oxidation. As well as destruction of cyanide, such a process is not suitable for destruction of the thiocyanate ion (SCN ).
- SCN thiocyanate ion
- An alternative process involves destruction of weak acid dissociable cyanide by oxidation with a mixture of sulphur dioxide and air. Again, cyanide is oxidised to cyanate and the process is not suitable for removing thiocyanate.
- An AVR treatment circuit involves acidification of cyanide liquors or slurries to lower the pH from an alkaline range to pH 3-5 resulting in conversion of free cyanide and weak complexes such as zinc, cadmium and nickel complexes to HCN which is then volatilised by passing air bubbles through the liquor or pulp.
- An air/HCN stream may then be scrubbed in a lime slurry or NaOH solution to convert HCN back to sodium cyanide for recycling.
- the AVR process is an option for treating moderate or strong cyanide liquors (over 500ppm weak acid dissociable cyanide), copper is precipitated as CuCN during the acidification stage.
- Cyanisorb process is similar to the AVR process above but differs in that clear solutions or slurries are processed at near neutral pH.
- the MNR process was developed by Metal Millennium Natural Resources and involves sulphidisation using NaSH and acidification, to pH less than 5, of copper/cyanide rich liquors precipitate synthetic chalcocite (Cu 2 S).
- the liquor may then be re-causticised to produce caustic cyanide or acidified further to form HCN gas which may be recovered by absorption.
- the copper by-product is saleable. Nevertheless, material handling of the chalcocite and potential co-precipitation of CuCN and CuSCN may be issues in plant design. Solvent extraction and ion exchange techniques are also possible alternatives for treatment of liquors containing free cyanide. However, they do not address recovery of cyanide from cyanide complexes such as copper cyanide complexes.
- the process may be applied to recovery of cyanide for use in a metallurgical or industrial process.
- the process ought not to be chemically intensive in comparison with prior art processes.
- the present invention provides a process for recovery of cyanide and metals from a liquor containing a compound or complex of cyanide and/or thiocyanide and metal generated by a metallurgical process including the steps of:
- the process is suitable for recovery of cyanide and/or metal from solutions containing very low concentrations of these components whether in cyanide or thiocyanide form.
- Thiocyanide compounds or complexes are also considered herein as compounds or complexes of cyanide electrochemically dissociable in accordance with the process of the invention.
- solution concentration the liquor containing the complexes of cyanide and metal may contain significantly less than 10g/l metal, a very low concentration.
- step (a) the electrochemical treatment step for electrochemical dissociation of the metal-cyanide or metal- thiocyanide complex in an electrochemical cell to form free cyanide which itself forms a further inventive aspect.
- This step allows higher free cyanide recovery, notably from thiocyanide present in the liquor.
- Thiocyanide may also be oxidised to free cyanide in the cell.
- the process can be applied to recovery of many different metals and may be particularly suitable for recovery of base metals such as copper, zinc and nickel, particularly from complexes of these with cyanide (base-metal- cyanide complexes).
- base metals such as copper, zinc and nickel
- base-metal- cyanide complexes base-metal- cyanide complexes
- Cu(CN) 2 ' , Cu(CN) 3 2" and Cu(CN) 4 3" complexes are the most significant. All may be present in a liquor from a gold leaching operation for gold ores containing copper or base metals. All the processes may also be used to recover precious metals such as silver, which are complexed with cyanide in precious metal-cyanide complexes.
- Metals may be recovered from the cathode or from the process in a form suitable for recovery by a suitable solid/liquid separation process.
- a suitable solid/liquid separation process For example, copper, silver or other metals may be recovered in a powder or granulated form by conducting solid-liquid separation in a hydrocyclone or similar device.
- the membrane process may be pressure or diffusion driven, being characterised as a process of ultrafiltration, nanofiltration or reverse osmosis, differences between which are described in Lein, L, "Nanofiltration: Trend of the Future!, Water Conditioning and Purification, September 1992, pp 24 to 27 and Cheryan, M et al, "Consider Nanofiltration for Membrane Separations", Chemical Engineering Progress, March 1994, pp 68 to 74, both of which are incorporated herein by reference. These references further describe specific characteristics of membranes for use in these processes though many membranes are proprietary in nature.
- Nanofiltration membranes prevent passage of materials, such as ions, that have size in excess of 10 to 20 angstroms.
- Ultrafiltration membranes prevent passage of ions having size in excess of 50 to 200 angstroms.
- Reverse osmosis membranes prevent passage of smaller ions and material having size greater than about 2 to 5 angstroms.
- Membrane processing for recovery of free cyanide may take place in one or more stages involving membrane modules of spiral, fibre, flat plates, tubular or other module design known in the art.
- Such processes may further be applied to the step of concentrating the recovered cyanide stream to enable re-use if desired.
- a typical pressure range would be 500 kPa to 8,000 kPa.
- the recovered cyanide stream or permeate may contain a very low concentration of cyanide in comparison to that required in a metallurgical process, for example a gold cyanide leaching process.
- the concentration of free cyanide may be upgraded by further membrane modules in which the cyanide is selectively retained by membranes of decreasing pore size or increasing "tightness".
- a number of stages may be required to achieve the requisite degree of concentration for recycling of cyanide to the metallurgical process. Such a process may be feasible in two to three stages.
- free cyanide, cyanide or thiocyanide complexes and compounds may be present in the liquor. These species may report at the anode of each electrochemical cell in which electrochemical dissociation occurs.
- the anode should be separated from the cathode at which copper or other metal deposits such that re-complexing with cyanide is limited.
- Cyanide can be removed from each electrochemical cell by conducting the membrane treatment step within the electrochemical cell to prevent re-complexing with base metal, such as copper.
- Free cyanide may also be recovered in a membrane treatment step conducted externally of the electrochemical cell. The membrane treatment step may be conducted for spent electrolyte or in a recirculating flow of electrolyte through the electrochemical cell.
- a number of electrowinning and membrane cells may be employed in a suitable electrochemical apparatus. The cells may be in series or parallel relation.
- an electrochemical apparatus for recovering metals by electrowinning from low concentration metal containing solutions including:
- a housing including at least one electrochemical cell and having inlet and outlet means to enable electrolyte to pass through at least one cell;
- the flow circulating means may include a baffle means located between the anode and cathode of each cell with the inlet and outlet means located to promote a circulation within the cell.
- the baffle could alternatively, and advantageously, serve as anode or cathode with a surrounding or adjacent electrode serving as cathode or anode, respectively.
- the baffle would preferably be constituted by the anode.
- an electrowinning unit may comprise a number of anodes and cathodes which may be located in cell units provided with electrolyte inlets and outlets.
- the anodes and cathodes which may be in the form of plates, may be retained in supporting frames held in pressure relation by a press.
- the press may be opened to recover metal deposited on the cathodes.
- the electrochemical cells may be configured to allow recovery of metal in a suitable solid/liquid separation device such as a hydrocyclone.
- the inlet means may include one or more port means such as nozzles, or orifices located, advantageously in spaced relation, to create a flow of electrolyte past the electrodes which is high in velocity in comparison with prior art electrowinning cells.
- the inlet ports may be arranged in banks or along the length of one side of each cell. Other arrangements are possible.
- the narrow diameter of ports, nozzles or orifices relative to an inlet manifold supplying electrolyte to the electrochemical apparatus may cause electrolyte velocity to increase. As a result, electrolyte may be injected or jetted into each electrochemical cell. A high degree of turbulence is also induced in the electrolyte flow and this promotes metal ion mass transfer.
- the inlet manifold may be connected to one side of a supporting frame being provided with an inlet gallery through which electrolyte flows, through the nozzles, ports or orifices and ultimately across the electrodes.
- Another side of the supporting frame may also be provided with outlet port means such as nozzles or orifices respectively connected to an outlet gallery and ultimately an outlet manifold.
- the outlet ports may be arranged in banks or along one side of each cell, typically that side opposed to the inlet ports. Other arrangements, including a staggered arrangement of inlet and outlet port means, are possible.
- Outlet port means may have larger diameter than the inlet port means.
- the diameter of the inlet nozzles, ports or orifices may progressively decrease toward a centre of the one side of the supporting frame such that the velocity profile increases toward a centre of the one side of the electrode supporting frame.
- This supporting frame may also be electrically connected to a supply of current in a conventional way. It may incorporate a gas vent for venting of anode gas, such as hydrogen, from each cell. More specifically, the anode and cathode of each cell may be supported by a supporting frame having opposed frame members provided with respective inlet and outlet port means, as described above, communicating each cell with inlet and outlet manifolds, said supporting frame having internal curved walls forming part of each cell. The curved walls further promote the circulating flow of electrolyte within the cell.
- a membrane may be incorporated in the electrowinning cell to remove species formed during electrowinning and, particularly when the electrochemical cell is to be employed in the recovery of cyanide.
- the membrane of a preferred embodiment of the invention, needs also to be permeable to cyanide with the cyanide permeate side of the cell connected to an outlet or outlet manifold such that cyanide can be removed from the cell without opportunity for re-complexing of cyanide and metal.
- Retentate is subjected to electrowinning of metal. Retentate may be recycled to the apparatus, treated in further stages or disposed of.
- pressure within the cell can drive the permeate flux.
- the outlet or outlet manifold may be connected specifically to receive permeate from the cell and direct it to a cyanide concentration step as above described.
- the retentate side may be connected, optionally through a separate manifold, to a solid/liquid separation device or hydrocyclone for collection of metal particles recovered by electrowinning. Otherwise retentate may be treated as described above.
- the process and apparatus of the present invention may be conveniently and advantageously be used for recovery of free cyanide and metals from solutions containing complexes of these, such as may be derived from precious metal leaching processes.
- metal recovery is also possible from solutions having much lower metal concentration or tenor than previously known providing the opportunity to operate without expensive concentration upgrading steps such as solvent extraction and ion exchange necessarily employed in prior art processes.
- solvent extraction is a commonplace step in recovery of copper from a copper leaching process.
- a process for treatment of an aqueous cyanide or thiocyanide bearing stream including a membrane treatment step for separating free cyanide, a cyanide complex or a thiocyanide from a stream containing same.
- free cyanide may be recovered for re-use in a process, particularly a metallurgical process using it.
- Such streams may be waste or other streams derived from leach plants, other metallurgical plants or waste water streams from other sources.
- the membrane processes described above may be directed to this purpose.
- Figure 1 is a schematic flowsheet for a process for recovering cyanide from a solution or liquor containing metal complexes thereof;
- Figure 2 is a schematic flowsheet for a process for concentrating cyanide in accordance with the concentration step of Figure 1 ;
- Figure 3 is a schematic diagram in side section of an electrochemical apparatus for conducting electrolysis of the metal-cyanide complex
- Figure 4 is a schematic diagram, in end section, of the electrochemical apparatus of Figure 2;
- Figure 5 is a schematic diagram along section line A-A of Figure 3;
- Figure 6 is a front view of a cell unit or cell supporting frame for use in an electrochemical apparatus as schematically represented in Figurers 3 and 4;
- Figure 7 is a first side view of the cell unit or cell supporting frame of Figure 6;
- Figure 8 is a top view of the cell unit or cell supporting frame of Figures 6 and 7;
- Figure 9 is a section view along section line A-A of Figure 6;
- Figure 10 is a second side view of the cell unit or cell supporting frame of Figures 6 to 9.
- FIG. 1 of the drawings there is shown a flowsheet for conducting a process in which cyanide and copper metal are recovered from an alkaline aqueous liquor stream 110 containing copper cyanide complexes including Cu(CN) 2 ⁇ , Cu(CN) 3 2" and Cu(CN) 4 3" complexes.
- Stream 110 may itself be derived from a membrane process for separating gold- cyanide and copper-cyanide complexes as described in US Patent No. 5961833, the contents of which are hereby incorporated herein by reference.
- Such a liquor stream 110 may be derived from a leach of a copper bearing gold ore.
- step 120 the copper cyanide complexes are dissociated in an electrochemical process in which cyanide reports to the anode and copper metal reports to the cathode of electrochemical cell(s) configured to conduct the process.
- electrochemical apparatus for performing this duty is described in further detail below.
- copper is electrowon, as a saleable product, perhaps in the form of granules or powder which may be recovered in a suitable solid/liquid separation step 170 including one or more devices such as hydrocyclones.
- the cyanide permeable membrane may be located in the electrowinning cell. As copper ions migrate to the cathode, cyanide ions pass through a membrane, migrating to a permeate collection manifold. The permeate stream may then be directed to further membrane treatment step, such as for concentration of cyanide for re-use in a metallurgical process for cyanide leaching of copper bearing gold ore. In another embodiment, a flow of copper depleted electrolyte may be directed to a membrane treatment step 140 involving reverse osmosis, ultrafiltration or nanofiltration steps in which cyanide is caused to permeate through a suitable membrane under imposition of a pressure gradient across the membrane.
- Membranes suitable for the membrane treatment step may be sourced under the trade marks DOW NF70 or Desal DK. Other membranes may be suitable noting the importance of pH to membrane selection.
- the membrane modules for membrane separation of free cyanide may be of spiral, fibre, flat plate, tubular or other known membrane unit type operated at a suitable pressure, for example, in the range 500 kPa to 8,000 kPa (0.5 to 8 MPa). A number of membrane modules, which may be arranged in stages may be used for this process.
- a recirculating flow 125 of part or all of the electrolyte may be maintained through electrochemical step 120 after treatment of electrolyte in membrane treatment step 140 for cyanide recovery.
- Cyanide containing permeate stream 150 may be directed to a further concentration step 160 for upgrading concentration of cyanide for re-use in the gold leaching process.
- Stream 154 may be recycled to the leaching process.
- Lean stream 157, lean in copper and cyanide, may be directed to further treatment or disposal.
- FIG. 2 shows a schematic of a cyanide concentration step 160 which itself involves membrane processes which selectively separate cyanide as retentate (concentrate) or otherwise.
- Stream 150 containing for example 1g/l cyanide, is directed first to membrane concentration unit 162 with concentrate stream 152, having concentration 5g/l cyanide, being directed to further membrane concentration unit 164 to generate concentrate stream 154 of concentration sufficient for recycle to a gold leaching process, say 15g/l concentration free cyanide.
- the lean cyanide stream 153 is directed to membrane concentration unit 166 with concentrate stream 155 being recycled to membrane concentration unit 162.
- the lean cyanide stream 157 containing a low concentration, say 0.01 g/l cyanide, may be directed to disposal or other treatment steps.
- Cyanide concentration may therefore involve two concentration steps but other concentration process flowsheets could be developed to perform the same duty. More concentration or separation steps could be employed as necessary.
- description was made of free cyanide and copper metal recovery from liquors containing complexes of these.
- the process of the invention is also suitable for recovery of cyanide and other base or precious metals from complexes thereof.
- the process would also be suitable for recovery of cyanide and silver from complexes thereof.
- the process is further suitable for recovery of free cyanide from other waste water streams.
- the process could be conducted by using a membrane process for recovery of free cyanide in association with a conventional electrochemical cell, in which electrolyte is recirculated through the cyanide membrane separation unit.
- the electrochemical process for dissociating copper-cyanide complexes may be conducted in an electrochemical cell or apparatus as described with reference to Figures 3 to 10.
- FIG 3 there is schematically shown an electrochemical apparatus 10 having a housing 30 incorporating a number of electrochemical cells 21.
- Housing 30 includes four electrochemical cells 21 each being provided with planar anodes 38 and cathodes 39. Other forms of anode 38 or cathode 39 could be used, for example cylindrical, rod or otherwise.
- each cathode 39 of cell 21 is a planar anode 38 forming a baffle around which electrolyte circulates in a high velocity turbulent flow across the anode and cathode surfaces.
- Cathode 39 may completely surround anode 38.
- an electrochemically inert baffle may be located between anode and cathode plates 38 and 39.
- the baffle may be of polymeric material.
- anodes and cathodes may be constructed from material known to be suitable for electrowinning application.
- stainless steel anodes and cathodes 38 and 39 may be employed.
- Type 316 stainless steel may be preferred.
- Electrical connection is made with anodes and cathodes 38 and 39 in conventional manner.
- the cells 21 are incorporated in cell units 23 held in a press between end plates 20 which may be of polymeric or other suitable material.
- the end plates 20 are of polypropylene.
- the apparatus may be assembled or disassembled by adjustment of pressure screw 18.
- electrochemical apparatus 10 may be operated in a recirculating mode with electrolyte being directed through membrane treatment step 140 for recovery of free cyanide, and then back to electrochemical apparatus 10 for further electrochemical treatment.
- a number of electrochemical treatment stages could be used.
- Leaving electrolyte may be depleted in copper which deposits on planar cathodes 39 as a powder or granulated deposit. In a turbulent regime, the metal solid may be transported from cathode 39 surfaces and may be recovered by solid/liquid separation in hydrocyclones for example.
- the leaving electrolyte is then passed to membrane treatment step 140 for recovery of free cyanide which may be concentrated for re-use in the metallurgical process as previously described.
- the membrane treatment step could be conducted within cell 21.
- anodes 38 could be separated from the remainder of the cell by a cyanide permeable membrane to achieve this.
- the entering electrolyte enters cells 21 through at least one port located where each branch pipe 14 enters each cell 21. As such a port is of lesser diameter then the diameter of the inlet manifold 16, electrolyte velocity is increased and turbulence is likewise increased. Electrolyte is therefore injected or jetted into the cells 21.
- the mass transfer rate of copper from ionic to metallic form is increased with copper recovery being possible even from very low concentration solutions, having copper tenor 1 g/l or even lower. This may also be understood to be the case for other metals.
- the circulation effect may be enhanced by orienting the inlet and outlet ports tangential to curved portions 33 of walls 21a of cells 21 as shown in Figure 4.
- the curved orientation of the walls 21a enhances the circulation effect.
- the supporting frames 210 for each cell unit 23 will now be described in greater detail with reference to Figures 6 to 10.
- the supporting frame 210 is provided with a number of frame members 211 , 212 and 213 which may be made of non- conductive polypropylene or other materials.
- Supporting frame 210 is supportive of, or connected to, plates 238 and 239 which respectively form the anode and cathode of electrochemical cell 21.
- Anode and cathode plates 238 and 239 may be of stainless steel or other suitable material. These are electrically connected to a contactor bar (not shown) and a current supply as known in the electrochemical art.
- Anode plate 238 may be located approximately centrally of cell 21. Centre line 21a of cell 21 may form the centre line of anode plate 238.
- Frame member 211 incorporates a number of inlet ports 240, of narrower diameter than the diameter of inlet manifold 16 or branch pipe 214. Two zones of inlet ports 240 are shown but ports could extend along the entire length of walls of frame member 211 defining cell 21. Electrolyte is pumped to each cell 21 through inlet manifold 16, branch pipe 214 and corner apertures 242 to inlet gallery 241. Inlet gallery 241 communicates with each cell 21 interior through drilled restrictions or apertures, of circular or other geometry, in frame member 211 which form ports 240. In this way, velocity and turbulence of electrolyte are increased.
- Ports 240 are conveniently located offset from a centre axis 21 a of cell 21 , and anode 238 to create a turbulent high velocity circulatory flow of electrolyte transversely across the electrodes with the ports 240 acting as jets.
- Corner apertures 242 may extend through the entire length of electrochemical apparatus 10.
- Corresponding apertures may be formed in one or both electrodes, especially cathode plates 239.
- the supporting frame 210 opposed frame members 211 and 213 are also provided with internal curved walls 233 which also promote a high velocity turbulent flow of electrolyte in cell 21.
- the leaving flow of electrolyte may be passed through outlet ports 250 to membrane treatment step 140 for recovery of free cyanide while metal can be recovered from the cathode in any convenient manner after membrane treatment.
- Ports 250 may also be located offset from a centre axis 21 a of each cell 21 , advantageously on the opposite side of anode 238 and centre axis 21a to ports 240, which further enhances the circulatory effect.
- the outlet ports 250 which may have larger diameter than inlet ports 240, are drilled apertures, of circular or other geometry, in frame member 213. In the drawings, outlet ports 250 are centrally located and staggered from the inlet ports 240. The staggering is apparent from Figures 6 to 10.
- FIG. 9 omitting anode 238 for clarity of illustration, shows the staggered arrangement in which ports 240 and 250 are at different levels within the cell 21.
- the outlet ports 250 could extend along the entire length of walls of frame member 213 defining cell 21.
- the outlet ports 250 communicate with outlet gallery 251 communicating with an outlet manifold 18 through corner apertures 244, again extending through apparatus 10.
- a solid/liquid separator such as a hydrocyclone may be used to recover metal powder from the cells 21 after membrane treatment step 140.
- a number of cell units 23 may be mounted together between end plates 20, all being supported by supporting arms 23a of cell unit 23 on a support means (not shown).
- End plates 20 may be polymeric, say of polypropylene.
- the cell units 23 may be mounted to be assembled/disassembled by tightening or loosening screw 18 shown in Figure 3.
- the electrochemical apparatus may be operated in recirculating mode to maximise recovery of cyanide and metal.
- a number of stages may be used, each employing apparatus of the same or similar type to that described above.
- the electrochemical apparatus is not restricted in its applicability to metal-cyanide complex electrolysis, as a step in free cyanide recovery, and it may also be applied to recovery of metals, particularly base metals, from low tenor metal ion containing solutions as well as species formed during electrolytic processes for recovery of metals whether in combination, or not, with a membrane separation process for such species.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Electrolytic Production Of Metals (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
Description
Claims
Applications Claiming Priority (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AUPQ5768A AUPQ576800A0 (en) | 2000-02-22 | 2000-02-22 | High rate electrowinning cell |
AUPQ576800 | 2000-02-22 | ||
AUPQ911700 | 2000-08-01 | ||
AUPQ9117A AUPQ911700A0 (en) | 2000-08-01 | 2000-08-01 | Cyanide and copper recovery process |
AUPR3212A AUPR321201A0 (en) | 2001-02-21 | 2001-02-21 | Process and apparatus for recovery of cyanide and metals |
AUPR321200 | 2001-02-21 | ||
PCT/AU2001/000177 WO2001062993A1 (en) | 2000-02-22 | 2001-02-22 | Process and apparatus for recovery of cyanide and metals |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1259652A1 EP1259652A1 (en) | 2002-11-27 |
EP1259652A4 true EP1259652A4 (en) | 2003-06-25 |
Family
ID=27158211
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP01907238A Withdrawn EP1259652A4 (en) | 2000-02-22 | 2001-02-22 | Process and apparatus for recovery of cyanide and metals |
Country Status (6)
Country | Link |
---|---|
US (1) | US20030089619A1 (en) |
EP (1) | EP1259652A4 (en) |
JP (1) | JP2003524071A (en) |
BR (1) | BR0108594A (en) |
CA (1) | CA2400806A1 (en) |
WO (1) | WO2001062993A1 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4628033B2 (en) * | 2004-07-29 | 2011-02-09 | アサヒプリテック株式会社 | Method for recovering Au from an aqueous solution containing cyanide |
JP4578228B2 (en) * | 2004-12-21 | 2010-11-10 | アサヒプリテック株式会社 | Method for recovering Au from an aqueous solution containing cyanide |
WO2010080761A1 (en) * | 2009-01-06 | 2010-07-15 | Epner R L | System for electrolytic recovery of metals with improved connection interface |
CA2752454C (en) | 2009-01-13 | 2020-01-14 | B.P.T. Bio Pure Technology Ltd. | Solvent and acid stable membranes and methods of manufacture thereof |
CN105274564B (en) * | 2014-05-30 | 2018-09-18 | 东北大学 | A kind of method of the recycling of electro-deposition high-concentration copper-containing cyanide bearing waste solution copper and cyanide |
WO2015196220A2 (en) * | 2014-06-18 | 2015-12-23 | Sirch Group (Pty) Ltd | A method of recovering base metals from low grade ores and residues |
CN111762909A (en) * | 2020-07-17 | 2020-10-13 | 莱特莱德(北京)环境技术股份有限公司 | Device and method for treating and recycling gold-containing barren solution |
Family Cites Families (29)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3847765A (en) * | 1972-12-20 | 1974-11-12 | Mitsubishi Petrochemical Co | Method for the treatment of cyanide-containing wastes |
CA1030098A (en) * | 1973-04-09 | 1978-04-25 | Hydrion Industries Ltd. | Direct recovery of metals from sulphide ores by leaching and electrolysis |
GB1423369A (en) * | 1973-09-24 | 1976-02-04 | Electricity Council | Electrolytic cells |
US3875041A (en) * | 1974-02-25 | 1975-04-01 | Kennecott Copper Corp | Apparatus for the electrolytic recovery of metal employing improved electrolyte convection |
US3979275A (en) * | 1974-02-25 | 1976-09-07 | Kennecott Copper Corporation | Apparatus for series electrowinning and electrorefining of metal |
US3954594A (en) * | 1974-09-04 | 1976-05-04 | Rockwell International Corporation | Electrochemical cell for decreasing the cyanide and heavy metal content of an aqueous solution |
CA1062651A (en) * | 1976-05-11 | 1979-09-18 | Anthony P. Holko | Process and apparatus for electrowinning metal from metal bearing solutions |
US4177116A (en) * | 1977-06-30 | 1979-12-04 | Oronzio DeNora Implanti Elettrochimici S.p.A. | Electrolytic cell with membrane and method of operation |
US4334968A (en) * | 1979-11-08 | 1982-06-15 | Sweeney Charles T | Apparatus for generation of chlorine/chlorine dioxide mixtures |
CH649789A5 (en) * | 1980-09-29 | 1985-06-14 | Sandoz Ag | ELECTROLYTIC CELL. |
DE3130742A1 (en) * | 1981-08-04 | 1983-02-24 | Uhde Gmbh, 4600 Dortmund | MONOPOLAR ELECTROLYTIC FILTER PRESS CELL |
US4585539A (en) * | 1982-08-17 | 1986-04-29 | Technic, Inc. | Electrolytic reactor |
US4632738A (en) * | 1982-09-03 | 1986-12-30 | Great Central Mines Ltd. | Hydrometallurgical copper process |
US4431496A (en) * | 1982-09-07 | 1984-02-14 | Institute Of Gas Technology | Depolarized electrowinning of zinc |
EP0151055B1 (en) * | 1984-01-09 | 1988-08-31 | Yves Heroguelle | Apparatus for the galvanic recovery of metals from diluted solutions |
FR2570087B1 (en) * | 1984-09-13 | 1986-11-21 | Rhone Poulenc Spec Chim | ELECTROLYTIC OXIDATION PROCESS AND ELECTROLYSIS ASSEMBLY FOR IMPLEMENTING IT |
US4652351A (en) * | 1985-12-19 | 1987-03-24 | Vaughan Daniel J | Electrochemical restoration of cyanide solutions |
FR2592317B1 (en) * | 1986-01-02 | 1988-04-22 | Univ Languedoc | METHOD FOR REGULATING AN ELECTRODIALYZER AND IMPROVED ELECTRODIALYSIS INSTALLATION. |
DE3640020C1 (en) * | 1986-11-24 | 1988-02-18 | Heraeus Elektroden | Electrolysis cell for the electrolytic deposition of metals |
US4834850A (en) * | 1987-07-27 | 1989-05-30 | Eltech Systems Corporation | Efficient electrolytic precious metal recovery system |
JPH01287289A (en) * | 1988-05-11 | 1989-11-17 | Permelec Electrode Ltd | Plural electrodes-type electrolytic cell |
US5057198A (en) * | 1988-05-19 | 1991-10-15 | Institut Gornogo Dela Sibirskogo Otdelenia Akademii Nauk Sssr | Method and electrolyzer for softening water |
US4923579A (en) * | 1988-09-12 | 1990-05-08 | Westinghouse Electric Corp. | Electrochemical process for zirconium alloy recycling |
US5266203A (en) * | 1992-01-30 | 1993-11-30 | Arrowhead Industrial Water, Inc. | Method for treating process streams containing cyanide and heavy metals |
US5225054A (en) * | 1992-03-02 | 1993-07-06 | Cominco Ltd. | Method for the recovery of cyanide from solutions |
US5411575A (en) * | 1994-03-25 | 1995-05-02 | E. I. Du Pont De Nemours And Company | Hydrometallurgical extraction process |
DE4438692C2 (en) * | 1994-10-29 | 2003-05-28 | Outokumpu Oy | Process for the electrochemical extraction of the metals copper, zinc, lead, nickel or cobalt |
US5868916A (en) * | 1997-02-12 | 1999-02-09 | Sachem, Inc. | Process for recovering organic hydroxides from waste solutions |
US5961833A (en) * | 1997-06-09 | 1999-10-05 | Hw Process Technologies, Inc. | Method for separating and isolating gold from copper in a gold processing system |
-
2001
- 2001-02-22 BR BR0108594A patent/BR0108594A/en not_active IP Right Cessation
- 2001-02-22 WO PCT/AU2001/000177 patent/WO2001062993A1/en not_active Application Discontinuation
- 2001-02-22 CA CA 2400806 patent/CA2400806A1/en not_active Abandoned
- 2001-02-22 US US10/204,590 patent/US20030089619A1/en not_active Abandoned
- 2001-02-22 JP JP2001561801A patent/JP2003524071A/en active Pending
- 2001-02-22 EP EP01907238A patent/EP1259652A4/en not_active Withdrawn
Non-Patent Citations (1)
Title |
---|
No further relevant documents disclosed * |
Also Published As
Publication number | Publication date |
---|---|
BR0108594A (en) | 2005-02-01 |
EP1259652A1 (en) | 2002-11-27 |
WO2001062993A1 (en) | 2001-08-30 |
JP2003524071A (en) | 2003-08-12 |
US20030089619A1 (en) | 2003-05-15 |
CA2400806A1 (en) | 2001-08-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6355175B1 (en) | Method for separating and isolating precious metals from non precious metals dissolved in solutions | |
JPS60106583A (en) | Method of treating aqueous flow containing precipitable material and acid and/or base | |
KR101947311B1 (en) | Treatment system and method for wastewater containing cyanide and heavy metal | |
CN110422948A (en) | Copper sulphate Sewage treatment metallic copper treatment process is electroplated | |
US20030089619A1 (en) | Process and apparatus for recovery of cyanide and metals | |
EP4100554A1 (en) | Extraction of copper, gold and other elements from waste materials | |
WO2004022796A1 (en) | Process and apparatus for recovery of cyanide and metals | |
CN106396164B (en) | A kind of industrial acidic wastewater treatment process | |
US5225054A (en) | Method for the recovery of cyanide from solutions | |
US3357823A (en) | Recovery of gold, silver, copper and zinc by alkaline cyaniding with electrodialysis | |
AU2001235239A1 (en) | Process and apparatus for recovery of cyanide and metals | |
CN103951119A (en) | Process for treating cyaniding barren liquor by combining membrane separation with two-stage membrane electrodialysis | |
CN115927852A (en) | Method for recovering gold, silver and copper from sulfur concentrate calcine washing waste liquid | |
CN112897771B (en) | Treatment device and treatment method for rare earth smelting wastewater | |
ZA200207563B (en) | Process and apparatus for recovery of cyanide and metals. | |
CN209456209U (en) | A kind of anolyte recovery and processing system | |
KR20030060304A (en) | Method for Recycling the Valuable Components from Cleaning Wastewater of Printed Circuit Board | |
CN215627329U (en) | Circuit board etching effluent treatment plant | |
CN113200635B (en) | Circuit board etching wastewater treatment device and method | |
CN218491602U (en) | Copper plating solution resource recovery device | |
CN218404350U (en) | Device for recycling and extracting lithium by taking lithium ore as raw material | |
AU2003258361A1 (en) | Process and apparatus for recovery of cyanide and metals | |
CN214192880U (en) | Waste lead-acid storage battery solid-phase electrolysis waste liquid treatment equipment | |
CN215856277U (en) | System for retrieve copper and cyanide in high-copper gold ore cyanidation gold extraction | |
CN107447233B (en) | Device and method for simultaneously separating and recovering multiple heavy metals in electroplating wastewater |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20020920 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
AX | Request for extension of the european patent |
Free format text: AL;LT;LV;MK;RO;SI |
|
A4 | Supplementary search report drawn up and despatched |
Effective date: 20030509 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: LAKEFIELD ORETEST PTY LTD Owner name: OCCTECH ENGINEERING PTY LTD. |
|
17Q | First examination report despatched |
Effective date: 20050201 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
RTI1 | Title (correction) |
Free format text: PROCESS FOR RECOVERY OF CYANIDE AND METALS |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20060524 |