CA2484416A1 - Method for refining concentrate containing precious metals - Google Patents
Method for refining concentrate containing precious metals Download PDFInfo
- Publication number
- CA2484416A1 CA2484416A1 CA002484416A CA2484416A CA2484416A1 CA 2484416 A1 CA2484416 A1 CA 2484416A1 CA 002484416 A CA002484416 A CA 002484416A CA 2484416 A CA2484416 A CA 2484416A CA 2484416 A1 CA2484416 A1 CA 2484416A1
- Authority
- CA
- Canada
- Prior art keywords
- matte
- smelting furnace
- suspension smelting
- created
- conducted
- 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.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 44
- 239000010970 precious metal Substances 0.000 title claims abstract description 37
- 239000012141 concentrate Substances 0.000 title claims abstract description 34
- 238000007670 refining Methods 0.000 title claims abstract description 12
- 238000003723 Smelting Methods 0.000 claims abstract description 55
- 239000000725 suspension Substances 0.000 claims abstract description 49
- 239000002893 slag Substances 0.000 claims abstract description 27
- 239000000463 material Substances 0.000 claims abstract description 7
- 238000002844 melting Methods 0.000 claims abstract description 6
- 230000008018 melting Effects 0.000 claims abstract description 6
- 230000004907 flux Effects 0.000 claims abstract description 5
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 4
- 239000003500 flue dust Substances 0.000 claims abstract description 4
- 239000012495 reaction gas Substances 0.000 claims abstract description 4
- 239000002699 waste material Substances 0.000 claims abstract description 4
- 238000002386 leaching Methods 0.000 claims description 12
- 238000009854 hydrometallurgy Methods 0.000 claims description 7
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 6
- 239000002244 precipitate Substances 0.000 claims description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 claims description 4
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims description 2
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 32
- 229910052759 nickel Inorganic materials 0.000 description 15
- 230000008569 process Effects 0.000 description 15
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 13
- 239000007789 gas Substances 0.000 description 10
- 239000010949 copper Substances 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 9
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 7
- 229910052802 copper Inorganic materials 0.000 description 7
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 5
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 229910052763 palladium Inorganic materials 0.000 description 4
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- 239000006227 byproduct Substances 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 229910052737 gold Inorganic materials 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 239000011593 sulfur Substances 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 229910000365 copper sulfate Inorganic materials 0.000 description 2
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 238000005868 electrolysis reaction Methods 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 238000005469 granulation Methods 0.000 description 2
- 230000003179 granulation Effects 0.000 description 2
- 239000013067 intermediate product Substances 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 239000002918 waste heat Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical class Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 1
- 235000014413 iron hydroxide Nutrition 0.000 description 1
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000009853 pyrometallurgy Methods 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000010944 silver (metal) Substances 0.000 description 1
Classifications
-
- 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
- C22B23/00—Obtaining nickel or cobalt
- C22B23/02—Obtaining nickel or cobalt by dry processes
- C22B23/025—Obtaining nickel or cobalt by dry processes with formation of a matte or by matte refining or converting into nickel or cobalt, e.g. by the Oxford process
-
- 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
- C22B11/02—Obtaining noble metals by dry processes
-
- 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
-
- 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
- C22B23/00—Obtaining nickel or cobalt
- C22B23/04—Obtaining nickel or cobalt by wet processes
- C22B23/0407—Leaching processes
- C22B23/0415—Leaching processes with acids or salt solutions except ammonium salts solutions
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
The invention relates to a method for refining precious metal concentrate, and according to said method, at least the precious metal concentrate (9), reaction gas (10), flux (11) and flue dust (12) to be treated are fed together into the reacton shaft (3) of a suspension smelting furnace (1); in the suspension smelting furnace, there are created separate phases, matte (8) and slag (7); and the slag created in the suspension smelting furnace is conducted into an electric furnace (2), so that there is created metallicized matte (14) and waste slag (13). Thereafter the matte (8) from the suspension smelting furnace is conducted to hydrometallurgical treatment (15), and the slag conducted into the electric furnace is treated together with a reducing agent and possibly with a material lowering the melting point or improving fluidity, and the obtained metallicized matte (14) is conducted either to hydrometallurgical treatment (16) or back into the suspension smelting furnace in (1).
Description
METHOD FOR REFINING CONCENTRATE CONTAINING PRECIOUS
METALS
The invention relates to a method for refining precious metal concentrate defined in the preamble of claim 1. In the method according to the invention, there is used a supension smelting furnace; the matte created in said, furnace is conducted into hydrometallurgical treatment, and the slag is reduced in an electric furnace. The metallicized matte created in the electric furnace is either fed back into the suspension smelting furnace or to hydrometallurgical treatment together or separately with the matte from the suspension smelting furnace.
Generally precious metals Au, Ag, Pt, Pd, Rh and Ir are in the wolrld produced by using various different manufacturing methods. Gold is produced either directly, by making use of the special features of gold, or as a side product in traditional copper production. The majority of world's platinum and a remarkable share of palladium is produced by using primary electric furnaces. The majority of world's palladium production is mainly based on nickel side production from ores by means of the suspension technipue, where the obtained intermediate product is nickel concentrate. An essential step in both processes is the use of a converter as part of the process. However, the use of a converter in the processes is harmful, as sulfur dioxide emissions and intermediate products caused by the transportation of melts are increased. Mattes obtained in the above described ways are further treated in hydrometallurgic plants. There are several different hydrometallurgical processes for the further refining of matte obtained from smelting, when precious metals should be recovered as side products.
The Finnish patent application 890 395 describes a manufacturing method and arrangement for producing high-grade nickel matte. According to said method, high-grade nickel matte is directly produced in a suspension smelting furnace.
At least the slag from the suspension smelting furnace is reduced in an electric furnace, where the electric furnace slag and the metallicized matte are formed, so that at least part of the metallicized matte is returned as feed to the suspension smelting furnace.
From the Finnish patent 94,538, there is known a method for manufacturing high-grade nickel matte and highly oxidized slag in a flash smelting furnace, and for reducing the slag from the flash smelting furnace and for sulfurizing the created matte in an electric furnace. The matte created in the flash smelting furnace and in the electric furnace are both conducted directly to hydrometallurgical further processing. A specific object of the invention is precisely to simplify the manufacturing process of high-grade nickel matte and to avoid the use of a converter in the process.
The object of the present invention is to bring forth a new type of method for refining precious metal concentrate, so that the precious metals are advantageously recovered by making use of the suspension smelting process.
Another object of the invention is to realize a refining process for a concentrate, the value of which lies in the precious metals contained therein, and where the nickel and/or copper only represent a side product in value.
The invention is characterized by what is set forth in the characterizing part of claim 1. Other embodiments of the invention are characterized by what is set forth in the rest of the claims.
The method according to the invention for refining precious metal concentrate has several advantages. The invention relates to a method for refining precious metal concentrate, and according to said method, at least the treated precious metal concentrate, the reaction gas, the slag forming agent, i.e. flux, and the flue dust are together fed into the reaction shaft of a suspension smelting furnace, so that in the suspension smelting furnace, there are created separate phases, matte and slag. The slag created in the suspension smelting furnace is conducted to an electric furnace, where metallicized matte and waste slag are formed, whereafter the matte from the suspension smelting furnace is conducted to hydrometallurgical treatment, and the slag conducted into the electric furnace is processed together with a reducing agent and possibly an agent that lowers the melting point or improves fluidity, and the created metallicized matte is conducted either to hydrometallurgical treatment or back into the suspension smelting furnace. According to the invention, in the refining of a precious metal concentrate containing precious metals, particularly platinum and palladium, there is advantageously used a suspension smelting furnace, such as a flash smelting furnace.
The method according to the invention for refining precious metal concentrate can also be utilized so that part of the supplied precious metal concentrate is replaced by sulfide concentrate. However, the process according to the invention essentially differs from said publications (FI patent 890,395 and FI
patent 94538), because the raw material used in the process is precious metal concentrate and not nickel concentrate, wherefore high-grade nickel matte is not created.
According to a preferred embodiment of the invention, the matte obtained from a suspension smelting furnace and the metallicized matte obtained from an electric furnace are granulated prior to the hydrometallurgical treatment.
According to various different applications of the invention, the matte from a suspension smelting furnace and the metallicized matte from an electric furnace are processed either in the same hydrometallurgical process or in different processes. According to a preferred embodiment of the invention, in the hydrometallurgical treatment, also the matte from the suspension smelting furnace is leached at least in one step. Thus the desired components of the concentrate are recovered. According to an embodiment of to the invention, also the metallicized matte from the electric furnace is leached at least in one step in the hydrometallurgical process. According to a preferred embodiment of the invention, the leaching of the matte takes place in sulfate atmosphere.
According to another embodiment of the invention, the leaching takes place in chloride atmosphere. According to yet another embodiment of the invention, precious metals are recovered from the leach residue. According to a preferred embodiment of the invention, the ferrous precipitate created in the hydrometallurgical treatment of matte and metallicized matte is conducted to a suspension smelting furnace.
In the process according to the invention, the energy contained by the raw material, such as the oxidizing heat contained by iron and sulfur, is utilized more efficiently than if the concentrate were treated in a primary electric furnace. Because in the process the matte phase is separated from slag in two steps, both in the suspension smelting furnace and in the electric furnace, the recovery of precious metals is remarkably increased when compared to processing in a primary electric furnace. In the process according to the invention, the amount of created exhaust gases is remarkably smaller than when using only a primary electric furnace in the treatment of the concentrate.
Along with the method according to the invention, also dust losses are reduced.
A relatively smaller quantity of gas facilitates the recovery and manufacturing of sulfur dioxide either into pure sulfur dioxide or into sulfuric acid. Now the necessary investments related to the gas and sulfur dioxide are smaller than in a process based on a corresponding primary electric furnace fulfilling the ecological requirements. The elimination of the use of converters results in the same advantages described above as the fact that primary electric furnaces are not used anymore.
The invention is described in more detail below with reference to the appended drawing.
Figure 1 Description of the process according to the invention.
Figure 1 illustrates a suspension smelting furnace 1 to be used in the method according to the invention, such as a flash smelting furnace. In the top part of the furnace reaction shaft 3 there is fed precious metal concentrate 9, oxidizing reaction gas 10, slag-forming agent, i.e. flux 11 and flue dust 12 obtained from the cooling of exhaust gases from the waste heat boiler 6. Into the suspension smelting furnace 1, there can also be fed iron precipitate created in the hydrometallurgic units 15 and 16 in the treatment of the matte. The ingredients fed into the reaction shaft 3 react with each other, and on the bottom of the 5 settler 4, there is formed a matte layer 8 and on top of it a slag layer 7.
The gases created in the suspension smelting furnace are removed through the uptake shaft 5 into a waste heat boiler 6, wherefrom the created flue dusts 12 are recirculated back into the suspension smelting furnace, and the exhaust gases 18 are conducted for further processing. A remarkable share of the concentrate 9 are precious metals that are accumulated in the settler, mainly in the matte phase 8. The matte 8 is subjected to granulation 17, and it is conducted into hydrometallurgical further processing 15, where the matte is leached, in which case the precious metals are leached last.
The slag 7 created in the suspension smelting furnace is conducted into an electric furnace 2, in which, apart from oxidized slag and reducing agent, there also is fed, if necessary, a sulfurous or other material for lowering the melting point or for improving the fluidity in order to adjust the melting point of the matte to be created. In the electric furnace, as a result from the reduction process, there is created metallicized matte 14 and slag 13. Without a sulfur addition, the sulfur content of the metallicized matte may remain very low, and respectively the melting point and viscosity may remain high. In the electric furnace, the precious metals are mainly transferred into a matte phase 14, which is further conducted, according to the invention, either to hydrometallurgical treatment 16, together with the matte from the suspension smelting furnace or separately. Another alternative is to recirculate the metallicized matte 14 or part thereof back into the suspension smelting furnace 1. Prior to the hydrometallurgical treatment 16 of the metallicized matte 14, the matte is subjected to granulation 19. The slag 13 created in the electric furnace 2 is waste slag, i.e. it is discarded. The precious metals are recovered in a hydrometallurgical process.
METALS
The invention relates to a method for refining precious metal concentrate defined in the preamble of claim 1. In the method according to the invention, there is used a supension smelting furnace; the matte created in said, furnace is conducted into hydrometallurgical treatment, and the slag is reduced in an electric furnace. The metallicized matte created in the electric furnace is either fed back into the suspension smelting furnace or to hydrometallurgical treatment together or separately with the matte from the suspension smelting furnace.
Generally precious metals Au, Ag, Pt, Pd, Rh and Ir are in the wolrld produced by using various different manufacturing methods. Gold is produced either directly, by making use of the special features of gold, or as a side product in traditional copper production. The majority of world's platinum and a remarkable share of palladium is produced by using primary electric furnaces. The majority of world's palladium production is mainly based on nickel side production from ores by means of the suspension technipue, where the obtained intermediate product is nickel concentrate. An essential step in both processes is the use of a converter as part of the process. However, the use of a converter in the processes is harmful, as sulfur dioxide emissions and intermediate products caused by the transportation of melts are increased. Mattes obtained in the above described ways are further treated in hydrometallurgic plants. There are several different hydrometallurgical processes for the further refining of matte obtained from smelting, when precious metals should be recovered as side products.
The Finnish patent application 890 395 describes a manufacturing method and arrangement for producing high-grade nickel matte. According to said method, high-grade nickel matte is directly produced in a suspension smelting furnace.
At least the slag from the suspension smelting furnace is reduced in an electric furnace, where the electric furnace slag and the metallicized matte are formed, so that at least part of the metallicized matte is returned as feed to the suspension smelting furnace.
From the Finnish patent 94,538, there is known a method for manufacturing high-grade nickel matte and highly oxidized slag in a flash smelting furnace, and for reducing the slag from the flash smelting furnace and for sulfurizing the created matte in an electric furnace. The matte created in the flash smelting furnace and in the electric furnace are both conducted directly to hydrometallurgical further processing. A specific object of the invention is precisely to simplify the manufacturing process of high-grade nickel matte and to avoid the use of a converter in the process.
The object of the present invention is to bring forth a new type of method for refining precious metal concentrate, so that the precious metals are advantageously recovered by making use of the suspension smelting process.
Another object of the invention is to realize a refining process for a concentrate, the value of which lies in the precious metals contained therein, and where the nickel and/or copper only represent a side product in value.
The invention is characterized by what is set forth in the characterizing part of claim 1. Other embodiments of the invention are characterized by what is set forth in the rest of the claims.
The method according to the invention for refining precious metal concentrate has several advantages. The invention relates to a method for refining precious metal concentrate, and according to said method, at least the treated precious metal concentrate, the reaction gas, the slag forming agent, i.e. flux, and the flue dust are together fed into the reaction shaft of a suspension smelting furnace, so that in the suspension smelting furnace, there are created separate phases, matte and slag. The slag created in the suspension smelting furnace is conducted to an electric furnace, where metallicized matte and waste slag are formed, whereafter the matte from the suspension smelting furnace is conducted to hydrometallurgical treatment, and the slag conducted into the electric furnace is processed together with a reducing agent and possibly an agent that lowers the melting point or improves fluidity, and the created metallicized matte is conducted either to hydrometallurgical treatment or back into the suspension smelting furnace. According to the invention, in the refining of a precious metal concentrate containing precious metals, particularly platinum and palladium, there is advantageously used a suspension smelting furnace, such as a flash smelting furnace.
The method according to the invention for refining precious metal concentrate can also be utilized so that part of the supplied precious metal concentrate is replaced by sulfide concentrate. However, the process according to the invention essentially differs from said publications (FI patent 890,395 and FI
patent 94538), because the raw material used in the process is precious metal concentrate and not nickel concentrate, wherefore high-grade nickel matte is not created.
According to a preferred embodiment of the invention, the matte obtained from a suspension smelting furnace and the metallicized matte obtained from an electric furnace are granulated prior to the hydrometallurgical treatment.
According to various different applications of the invention, the matte from a suspension smelting furnace and the metallicized matte from an electric furnace are processed either in the same hydrometallurgical process or in different processes. According to a preferred embodiment of the invention, in the hydrometallurgical treatment, also the matte from the suspension smelting furnace is leached at least in one step. Thus the desired components of the concentrate are recovered. According to an embodiment of to the invention, also the metallicized matte from the electric furnace is leached at least in one step in the hydrometallurgical process. According to a preferred embodiment of the invention, the leaching of the matte takes place in sulfate atmosphere.
According to another embodiment of the invention, the leaching takes place in chloride atmosphere. According to yet another embodiment of the invention, precious metals are recovered from the leach residue. According to a preferred embodiment of the invention, the ferrous precipitate created in the hydrometallurgical treatment of matte and metallicized matte is conducted to a suspension smelting furnace.
In the process according to the invention, the energy contained by the raw material, such as the oxidizing heat contained by iron and sulfur, is utilized more efficiently than if the concentrate were treated in a primary electric furnace. Because in the process the matte phase is separated from slag in two steps, both in the suspension smelting furnace and in the electric furnace, the recovery of precious metals is remarkably increased when compared to processing in a primary electric furnace. In the process according to the invention, the amount of created exhaust gases is remarkably smaller than when using only a primary electric furnace in the treatment of the concentrate.
Along with the method according to the invention, also dust losses are reduced.
A relatively smaller quantity of gas facilitates the recovery and manufacturing of sulfur dioxide either into pure sulfur dioxide or into sulfuric acid. Now the necessary investments related to the gas and sulfur dioxide are smaller than in a process based on a corresponding primary electric furnace fulfilling the ecological requirements. The elimination of the use of converters results in the same advantages described above as the fact that primary electric furnaces are not used anymore.
The invention is described in more detail below with reference to the appended drawing.
Figure 1 Description of the process according to the invention.
Figure 1 illustrates a suspension smelting furnace 1 to be used in the method according to the invention, such as a flash smelting furnace. In the top part of the furnace reaction shaft 3 there is fed precious metal concentrate 9, oxidizing reaction gas 10, slag-forming agent, i.e. flux 11 and flue dust 12 obtained from the cooling of exhaust gases from the waste heat boiler 6. Into the suspension smelting furnace 1, there can also be fed iron precipitate created in the hydrometallurgic units 15 and 16 in the treatment of the matte. The ingredients fed into the reaction shaft 3 react with each other, and on the bottom of the 5 settler 4, there is formed a matte layer 8 and on top of it a slag layer 7.
The gases created in the suspension smelting furnace are removed through the uptake shaft 5 into a waste heat boiler 6, wherefrom the created flue dusts 12 are recirculated back into the suspension smelting furnace, and the exhaust gases 18 are conducted for further processing. A remarkable share of the concentrate 9 are precious metals that are accumulated in the settler, mainly in the matte phase 8. The matte 8 is subjected to granulation 17, and it is conducted into hydrometallurgical further processing 15, where the matte is leached, in which case the precious metals are leached last.
The slag 7 created in the suspension smelting furnace is conducted into an electric furnace 2, in which, apart from oxidized slag and reducing agent, there also is fed, if necessary, a sulfurous or other material for lowering the melting point or for improving the fluidity in order to adjust the melting point of the matte to be created. In the electric furnace, as a result from the reduction process, there is created metallicized matte 14 and slag 13. Without a sulfur addition, the sulfur content of the metallicized matte may remain very low, and respectively the melting point and viscosity may remain high. In the electric furnace, the precious metals are mainly transferred into a matte phase 14, which is further conducted, according to the invention, either to hydrometallurgical treatment 16, together with the matte from the suspension smelting furnace or separately. Another alternative is to recirculate the metallicized matte 14 or part thereof back into the suspension smelting furnace 1. Prior to the hydrometallurgical treatment 16 of the metallicized matte 14, the matte is subjected to granulation 19. The slag 13 created in the electric furnace 2 is waste slag, i.e. it is discarded. The precious metals are recovered in a hydrometallurgical process.
Both in a suspension smelting furnace and in an electric furnace, precious metals are mainly trasferred to the matte phase, from which they are recovered in a hydrometallurgical process. Both. the matte 8 from the suspension smelting furnace and the metallicized matte 14 from the electric furnace are leached either in the same leaching line or separately. The leaching steps are dependent on the contents of the precious metal concentrate to be treated.
According to a preferred embodiment of the invention, the leaching is carried out in a sulfate atmosphere, i.e. the solution at some stage contains sulfate.
Now the cobalt and nickel possibly contained in the concentrate are leached in the first selective pressure leaching step as sulfate. In the same step there also is leached iron that can at the same time be precipitated as iron hydroxide.
Nickel is recovered as salt, or it is turned into metal in the electrolysis.
In the second leaching step, copper is leached as copper sulfate, which can be separated as such or turned into metallic copper in the electrolysis. Copper sulfate can also be crystallized and fed back into the suspension smelting furnace after drying. By adjusting the degree of oxidation in the leaching process and the oxidation in the pyrometallurgical process, the sulfate balance of the solution can be affected. The precious metals are left in the leach residue. The precious metal content of the leach residue is increased for instance by means of a strong sulfuric acid and sulfur dioxide treatment. The created concentrated precipitate is a good raw material for various precious metal refineries. According to an embodiment of the ,present invention, the leaching is carried out in a chloride atmosphere, in which case there is used chloride gas in the leaching, and in the solution, there are created cobalt, nickel, copper and iron chlorides.
The invention is illustrated with reference to an example below.
According to a preferred embodiment of the invention, the leaching is carried out in a sulfate atmosphere, i.e. the solution at some stage contains sulfate.
Now the cobalt and nickel possibly contained in the concentrate are leached in the first selective pressure leaching step as sulfate. In the same step there also is leached iron that can at the same time be precipitated as iron hydroxide.
Nickel is recovered as salt, or it is turned into metal in the electrolysis.
In the second leaching step, copper is leached as copper sulfate, which can be separated as such or turned into metallic copper in the electrolysis. Copper sulfate can also be crystallized and fed back into the suspension smelting furnace after drying. By adjusting the degree of oxidation in the leaching process and the oxidation in the pyrometallurgical process, the sulfate balance of the solution can be affected. The precious metals are left in the leach residue. The precious metal content of the leach residue is increased for instance by means of a strong sulfuric acid and sulfur dioxide treatment. The created concentrated precipitate is a good raw material for various precious metal refineries. According to an embodiment of the ,present invention, the leaching is carried out in a chloride atmosphere, in which case there is used chloride gas in the leaching, and in the solution, there are created cobalt, nickel, copper and iron chlorides.
The invention is illustrated with reference to an example below.
Example The method according to the invention was applied for the precious metal concentrate mentioned above, so that part of said concentrate was replaced by nickel concentrate. The iron precipitate created in the hydrometallurgic unit was recirculated back into the suspension smelting furnace. The abbreviation PGM
means precious metals.
The analyses and the material flow into the suspension smelting furnace:
Precious metal concentrate Nickel concentrate Fe precipitate Share % 75 22 3 Analysis Ni % 2 9 Cu % 10 3 Fe % 23 39 58 S % 20 27 Si02 % 28 14 AI203 % 4 1 Mg0 % 8 6 PGM ppm 75 3 When applying oxygen enrichment in the feed gas and a suitable degree of oxidation, as well as when taking into account the exhaust air, the oil demand for the heat balance, the recirculating dust quantities, the required fluxes and, as regards the electric furnace, the need for coke and a small amount of concentrate for the sulfurizing the matte, the following products were obtained from the suspension smelting furnace and from the electric furnace.
means precious metals.
The analyses and the material flow into the suspension smelting furnace:
Precious metal concentrate Nickel concentrate Fe precipitate Share % 75 22 3 Analysis Ni % 2 9 Cu % 10 3 Fe % 23 39 58 S % 20 27 Si02 % 28 14 AI203 % 4 1 Mg0 % 8 6 PGM ppm 75 3 When applying oxygen enrichment in the feed gas and a suitable degree of oxidation, as well as when taking into account the exhaust air, the oil demand for the heat balance, the recirculating dust quantities, the required fluxes and, as regards the electric furnace, the need for coke and a small amount of concentrate for the sulfurizing the matte, the following products were obtained from the suspension smelting furnace and from the electric furnace.
Material flows of the feed mixture quantity and analyses:
Suspension smelting furnace Electric furnace Matte Slag Matte Slag Material flow of feed 12 71 4 67 Analyses Ni % 20 1,3 24 0,1 Cu % 54 2,4 31 0.7 S % 21 0,2 8,0 0.3 Fe % 3, 36 34 37 Si0% 0,0 32 0,0 35 Mg0 % 0,0 9,7 10 3,5 PGM ppm 440 2,2 32 0,4 The gas created in a suspension smelting furnace contains more than 10%
sulfur dioxide, and is thus suitable for the production of sulfuric acid. The exhaust gases from the electric furnace are nearly free of sulfur dioxide, and consequently do not strain the environment. The method described above also functions without nickel and even so that a large part of the copper is replaced by iron, if the source material does not contain a sufficient amount of copper.
For a man skilled in the art, it is obvious that the different embodiments of the invention are not restricted to the examples given above, but may vary within the scope of the appended claims.
Suspension smelting furnace Electric furnace Matte Slag Matte Slag Material flow of feed 12 71 4 67 Analyses Ni % 20 1,3 24 0,1 Cu % 54 2,4 31 0.7 S % 21 0,2 8,0 0.3 Fe % 3, 36 34 37 Si0% 0,0 32 0,0 35 Mg0 % 0,0 9,7 10 3,5 PGM ppm 440 2,2 32 0,4 The gas created in a suspension smelting furnace contains more than 10%
sulfur dioxide, and is thus suitable for the production of sulfuric acid. The exhaust gases from the electric furnace are nearly free of sulfur dioxide, and consequently do not strain the environment. The method described above also functions without nickel and even so that a large part of the copper is replaced by iron, if the source material does not contain a sufficient amount of copper.
For a man skilled in the art, it is obvious that the different embodiments of the invention are not restricted to the examples given above, but may vary within the scope of the appended claims.
Claims (11)
1. A method for refining precious metal concentrate, in which method:
a) at least the precious metal concentrate (9), reaction gas (10), flux (11) and flue dust (12) to be treated are together fed into the reaction shaft (3) of a suspension smelting furnace (1);
b) in the suspension smelting furnace, there are created separate phases, matte (8) and slag (7);
c) the slag created in the suspension smelting furnace is conducted into an electric furnace (2), so that there are created metallicized matte (14) and waste slag (13), characterized in that d) the matte (8) from the suspension smelting furnace is conducted to hydrometallurgical treatment (15), and e) the slag conducted into the electric furnace is treated together with a reducing agent and possibly together with a material lowering the melting point or improving the fluidity, and the created metallicized matte (14) is conducted either to hydrometallurgical treatment (16) or back into the suspension smelting furnace (1).
a) at least the precious metal concentrate (9), reaction gas (10), flux (11) and flue dust (12) to be treated are together fed into the reaction shaft (3) of a suspension smelting furnace (1);
b) in the suspension smelting furnace, there are created separate phases, matte (8) and slag (7);
c) the slag created in the suspension smelting furnace is conducted into an electric furnace (2), so that there are created metallicized matte (14) and waste slag (13), characterized in that d) the matte (8) from the suspension smelting furnace is conducted to hydrometallurgical treatment (15), and e) the slag conducted into the electric furnace is treated together with a reducing agent and possibly together with a material lowering the melting point or improving the fluidity, and the created metallicized matte (14) is conducted either to hydrometallurgical treatment (16) or back into the suspension smelting furnace (1).
2. A method according to claim 1, characterized in that part of the precious metal concentrate (9) to be fed into the suspension smelting furnace is replaced by sulfide concentrate.
3. A method according to claim 1 or 2, characterized in that the matte (8) from the suspension smelting furnace and the metallicized matte (14) from the electric furnace are granulated before the hydrometallurgical treatment.
4. A method according to any of the claims 1 - 3, characterized in that the matte from the suspension smelting furnace and the metallicized matte from the electric furnace are treated in the same hydrometallurgical process.
5. A method according to any of the claims 1 - 3, characterized in that the matte from the suspension smelting furnace and the metallicized matte from the electric furnace are treated in separate hydrometallurgical processes.
6. A method according to any of the claims 1 - 5, characterized in that in the hydrometallurgical treatment (15), the matte (8) from the suspension smelting furnace is leached in at least one step.
7. A method according to any of the claims 1 - 5, characterized in that in the hydrometallurgical treatment (16), the metallicized matte (14) from the electric furnace is leached in at least one step.
8. A method according to claim 6 or 7, characterized in that the leaching is carried out in sulfate atmosphere.
9. A method according to claim 6 or 7, characterized in that the leaching is carried out in chloride atmosphere.
10. A method according to claims 6, 7, 8 or 9, characterized in that the precious metals are recovered from the leach residue.
11. A method according to any of the preceding claims, characterized in that the ferrous precipitate created in the hydrometallurgical treatment of matte and metallicized matte is conducted into a suspension smelting furnace.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI20020835 | 2002-05-03 | ||
FI20020835A FI114808B (en) | 2002-05-03 | 2002-05-03 | Process for the processing of precious metal |
PCT/FI2003/000343 WO2003093516A1 (en) | 2002-05-03 | 2003-05-02 | Method for refining concentrate containing precious metals |
Publications (1)
Publication Number | Publication Date |
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CA2484416A1 true CA2484416A1 (en) | 2003-11-13 |
Family
ID=8563870
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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CA002484416A Abandoned CA2484416A1 (en) | 2002-05-03 | 2003-05-02 | Method for refining concentrate containing precious metals |
Country Status (15)
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US (1) | US20050217422A1 (en) |
EP (1) | EP1509628A1 (en) |
JP (1) | JP2005524768A (en) |
KR (1) | KR20040099476A (en) |
CN (1) | CN1650037A (en) |
AU (1) | AU2003240873A1 (en) |
BR (1) | BR0309679A (en) |
CA (1) | CA2484416A1 (en) |
EA (1) | EA006620B1 (en) |
FI (1) | FI114808B (en) |
MX (1) | MXPA04010718A (en) |
PL (1) | PL372600A1 (en) |
RS (1) | RS95504A (en) |
WO (1) | WO2003093516A1 (en) |
ZA (1) | ZA200408570B (en) |
Families Citing this family (16)
Publication number | Priority date | Publication date | Assignee | Title |
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FI115638B (en) * | 2002-12-05 | 2005-06-15 | Outokumpu Oy | Procedure for treating slag |
FI119774B (en) * | 2007-06-20 | 2009-03-13 | Outotec Oyj | Process for the treatment of cobalt-containing copper concentrate |
FI120157B (en) * | 2007-12-17 | 2009-07-15 | Outotec Oyj | A process for refining copper concentrate |
JP5609121B2 (en) * | 2010-01-21 | 2014-10-22 | 新日鐵住金株式会社 | Concentration method of platinum to molten copper phase to recover platinum in copper iron scrap |
FI20110278A0 (en) * | 2011-08-29 | 2011-08-29 | Outotec Oyj | A process for recovering metals from a sulphide concentrate |
CN102605191B (en) * | 2012-04-16 | 2013-12-25 | 阳谷祥光铜业有限公司 | Method for directly producing row copper by copper concentrate |
FI124028B (en) | 2012-06-13 | 2014-02-14 | Outotec Oyj | Process and arrangement for refining copper concentrate |
RU2531333C2 (en) * | 2012-06-25 | 2014-10-20 | Радик Расулович Ахметов | Method of extraction of platinoids from spent automotive catalysts |
CN104451195B (en) * | 2014-11-21 | 2016-05-18 | 邱江波 | The flash smelting method of lateritic nickel ore |
CN104561519A (en) * | 2014-12-03 | 2015-04-29 | 金川集团股份有限公司 | Treatment method of high-magnesium noble metal concentrate |
RU2614293C2 (en) * | 2015-06-04 | 2017-03-24 | Общество с ограниченной ответственностью "Институт Гипроникель" | Method of low-autogenous raw material processing in flash smelting furnaces |
WO2017185158A1 (en) * | 2016-04-28 | 2017-11-02 | Eldorado Gold Corporation | Method for reducing arsenic content in arsenic-bearing gold material |
CN107119195B (en) * | 2017-04-27 | 2019-01-04 | 山东河西黄金集团有限公司 | Method based on high S high Fe gold mine and copper-bearing waste material direct melting recycling gold and copper |
US10662500B2 (en) | 2018-01-24 | 2020-05-26 | Heraeus Deutschland GmbH & Co. KG | Process for the recovery of precious metal from petrochemical process residues |
CN112359227B (en) * | 2020-11-12 | 2022-05-20 | 中国恩菲工程技术有限公司 | Method for extracting cobalt from pyrometallurgical nickel smelting process |
CN115433838A (en) * | 2022-08-15 | 2022-12-06 | 金川镍钴研究设计院有限责任公司 | Method for enriching precious metals by treating Nielsen concentrate through pyrogenic process |
Family Cites Families (7)
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JPS5149119A (en) * | 1974-10-28 | 1976-04-28 | Nippon Mining Co | Doseirenniokeru rendanrosogyoho |
SE444578B (en) * | 1980-12-01 | 1986-04-21 | Boliden Ab | PROCEDURE FOR THE RECOVERY OF METAL CONTENTS FROM COMPLEX SULFIDIC METAL RAW MATERIALS |
SE453200B (en) * | 1984-09-28 | 1988-01-18 | Boliden Ab | PROCEDURE FOR THE RECOVERY OF PRECIOUS METALS OF SILVER-rich, HALOGENEOUS MATERIALS |
FI84368B (en) * | 1989-01-27 | 1991-08-15 | Outokumpu Osakeyhtioe | Process and equipment for producing nickel fine matte |
FI94538C (en) * | 1992-06-18 | 1999-11-09 | Outokumpu Harjavalta Metals Oy | Process for the manufacture of nickel fine stone and metallised stone |
AP538A (en) * | 1992-06-26 | 1996-09-18 | Intec Pty Ltd | Production of metal from minerals |
FI98073C (en) * | 1995-08-14 | 1997-04-10 | Outokumpu Eng Oy | Process for the hydrometallurgical recovery of nickel from two different types of nickel stone |
-
2002
- 2002-05-03 FI FI20020835A patent/FI114808B/en not_active IP Right Cessation
-
2003
- 2003-05-02 CA CA002484416A patent/CA2484416A1/en not_active Abandoned
- 2003-05-02 AU AU2003240873A patent/AU2003240873A1/en not_active Abandoned
- 2003-05-02 RS YUP-955/04A patent/RS95504A/en unknown
- 2003-05-02 PL PL03372600A patent/PL372600A1/en not_active Application Discontinuation
- 2003-05-02 BR BR0309679-3A patent/BR0309679A/en not_active IP Right Cessation
- 2003-05-02 EP EP03730239A patent/EP1509628A1/en not_active Withdrawn
- 2003-05-02 EA EA200401237A patent/EA006620B1/en not_active IP Right Cessation
- 2003-05-02 WO PCT/FI2003/000343 patent/WO2003093516A1/en not_active Application Discontinuation
- 2003-05-02 KR KR10-2004-7017730A patent/KR20040099476A/en not_active Application Discontinuation
- 2003-05-02 CN CNA038100134A patent/CN1650037A/en active Pending
- 2003-05-02 MX MXPA04010718A patent/MXPA04010718A/en unknown
- 2003-05-02 JP JP2004501650A patent/JP2005524768A/en not_active Abandoned
- 2003-05-02 US US10/513,164 patent/US20050217422A1/en not_active Abandoned
-
2004
- 2004-10-22 ZA ZA200408570A patent/ZA200408570B/en unknown
Also Published As
Publication number | Publication date |
---|---|
EP1509628A1 (en) | 2005-03-02 |
JP2005524768A (en) | 2005-08-18 |
FI114808B (en) | 2004-12-31 |
ZA200408570B (en) | 2005-04-22 |
FI20020835A (en) | 2003-11-04 |
EA006620B1 (en) | 2006-02-24 |
BR0309679A (en) | 2005-03-01 |
WO2003093516A1 (en) | 2003-11-13 |
PL372600A1 (en) | 2005-07-25 |
EA200401237A1 (en) | 2005-06-30 |
MXPA04010718A (en) | 2005-03-07 |
CN1650037A (en) | 2005-08-03 |
AU2003240873A1 (en) | 2003-11-17 |
FI20020835A0 (en) | 2002-05-03 |
KR20040099476A (en) | 2004-11-26 |
US20050217422A1 (en) | 2005-10-06 |
RS95504A (en) | 2007-02-05 |
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