A method for removing arsenic and extracting copper from black copper mud by short process

Abstract

The present application belongs to the technical field of metal smelting, and particularly relates to a method for dearsenifying and copper extraction from black copper mud by a short process. The black copper mud is mixed with lead sulfate to obtain a mixture; the mixture is smelted to obtain a dearsenifying residual product and a volatile condensate product; the dearsenifying residual product comprises elemental Cu and PbS, and the volatile condensate product comprises As2O3; the dearsenifying residual product is subjected to vacuum distillation separation to obtain elemental Cu. The black copper mud is mixed with lead sulfate and then smelted, so that PbSO4 is directed to oxidize Cu3As to generate As2O3, Cu and PbS, and elemental Cu can be directly recovered from the black copper mud by a two-step short process, and the comprehensive utilization of valuable elements is realized; and the process for recovering elemental Cu is short, simple in operation, efficient, economical and easy to operate, and is easy to be applied in industrialization.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal smelting, and particularly relates to a method for short-process dearsenification and copper extraction from black copper mud. BACKGROUND

[0002] In the process of copper deposition and impurity removal by electrodeposition, As, Sb, Bi and other impurities in the copper electrolyte will be deposited together with Cu at the cathode. The mud-like substance (containing Cu, As, Sb, Bi, Pb, etc.) produced at the cathode is called black copper mud. The arsenic content in the black copper mud is between 10-40wt%, which not only seriously affects the quality of the cathode copper, but also poses a threat to the safety of the surrounding environment. The copper content in the black copper mud is between 30-60wt%, which has considerable economic value. The black copper mud can be treated by acid method, alkali method or electrolysis method to recover the valuable metals therein, achieving resourceization and harmlessness. The black copper mud can also be returned to the fire refining process to maximize the use of valuable metals therein, but there are problems of arsenic recycling and accumulation and occupation of production capacity.

[0003] In the research on dearsenification of black copper mud, there are mainly fire dearsenification and wet dearsenification. The principle of fire dearsenification of black copper mud is to use the property that As2O3 is easy to volatilize under high temperature conditions, and to separate arsenic in the form of As2O3 from the waste slag by high-temperature roasting of the arsenic-containing waste slag, so as to separate arsenic from other valuable metals and achieve dearsenification. The advantages of fire dearsenification are mature technology, wide application range and simple process flow. The principle of wet dearsenification of black copper mud is to leach arsenic in the form of arsenate, arsenite and thioarsenite. Among them, acid leaching dearsenification is simple and easy to operate, has good selectivity for high-arsenic copper ore and high arsenic leaching rate, and can also achieve arsenic solidification at the same time.

[0004] At present, the treatment of black copper mud has become a problem that needs to be solved for copper smelting enterprises, and the above existing treatment methods cannot directly obtain elemental copper. SUMMARY

[0005] The purpose of the present application is to provide a method for short-process dearsenification and copper extraction from black copper mud. The method provided by the present application can directly extract elemental copper from black copper mud while achieving dearsenification, and the process segment for recovering elemental copper is more suitable for industrial application.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] The present application provides a method for short-process dearsenification and copper extraction from black copper mud, comprising the following steps:

[0008] Mixing black copper mud and lead sulfate to obtain a mixture; smelting the mixture to obtain a dearsenification residual product and a volatile condensation product; the dearsenification residual product comprises elemental Cu and PbS, and the volatile condensation product comprises As2O3.

[0009] The residual product is separated by vacuum distillation to obtain elemental Cu.

[0010] Preferably, the temperature of the smelting is 300-800℃; the holding time is 30-130 min.

[0011] Preferably, the heating rate from room temperature to the temperature of the smelting is 10-15℃ / min.

[0012] Preferably, the main component of the black copper mud is Cu3As; the content of arsenic in the black copper mud is 10-30wt%, and the content of copper is 30-60wt%.

[0013] Preferably, the mass ratio of the black copper mud to the lead sulfate is 1:0.4-0.6.

[0014] Preferably, the average particle size of the mixture is 75-90μm; before the smelting, the mixture is dried at a temperature of 100-110℃ for 2-4h.

[0015] Preferably, the conditions of the vacuum distillation separation include: the distillation pressure is 1-1000Pa; the distillation temperature is 500-800℃, and the holding time is 30-120min; the heating rate from room temperature to the distillation temperature is 10-15℃ / min.

[0016] Preferably, the purity of the elemental Cu is >98%.

[0017] Preferably, the elemental Cu is used as raw material for copper refining.

[0018] Preferably, the vacuum distillation separation also obtains PbS vapor, which is condensed and used as raw material for lead smelting.

[0019] The present application provides a method for dearsenifying and copper extraction from black copper mud by short process, comprising the following steps: mixing black copper mud and lead sulfate to obtain a mixture; smelting the mixture to obtain a dearsenifying residual product and a volatile condensate product; the dearsenifying residual product comprises elemental Cu and PbS, and the volatile condensate product comprises As2O3; vacuum distillation separation is performed on the dearsenifying residual product to obtain elemental Cu. The present application mixes black copper mud and lead sulfate and then smelts. The directional oxidation of PbSO4 to Cu3As to generate As2O3, Cu and PbS is realized, and according to the difference in saturated vapor pressure, Cu and PbS are not volatilized and remain in the residual product to obtain a dearsenifying residual product; As is removed in the form of As2O3 vapor to form a volatile condensate product, so that the separation of Cu and As in black copper mud is realized. The present application realizes the effective separation of Cu and As in high-arsenic copper hazardous waste, i.e. black copper mud, by smelting; then, the separation of PbS and Cu is realized by vacuum distillation separation, and elemental Cu product can be directly obtained. The method provided by the present application can realize the direct recovery of elemental Cu from black copper mud by two-step short process, and realizes the comprehensive utilization of valuable elements; and the process for recovering elemental Cu is short, simple in operation, efficient, economical and easy to operate, and easy to be applied in industrialization.

[0020] Further, in the present application, the temperature of smelting is 300-800 DEG C. By controlling the temperature of smelting to be 300-800 DEG C, the present application realizes the effective dearsenification of black copper mud under low temperature conditions, and has the characteristics of environmental protection, economy and strong operability, and is easy to be applied in industrialization.

[0021] Further, in the present application, the purity of elemental Cu is > 98%, and the elemental Cu is used as raw material for copper refining. The elemental Cu separated by the present application has high purity, and can be directly returned to the copper refining system, so that the comprehensive utilization of valuable elements is realized.

[0022] From the results of the examples, it can be known that the recovery rate of Cu in the method for dearsenifying and copper extraction from black copper mud provided by the present application is higher than 95%, the purity is greater than 98%, which meets the purity standard of copper refining; the removal rate of lead sulfide is higher than 99%; the removal rate of arsenic is higher than 95%, the purity of arsenic trioxide is greater than 99%, and the direct recovery rate of As is higher than 90%. In summary, the method for dearsenifying and copper extraction from black copper mud provided by the present application realizes the dearsenification and copper extraction from black copper mud in copper smelting by low-temperature short process, the process is short, the operation is simple, the resource recovery rate is improved, and the method has good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The flow chart of the method for dearsenifying and copper extraction from black copper mud provided by the present application is shown in the figure. DETAILED DESCRIPTION

[0024] The application provides a method for short-process dearsenification and copper extraction from black copper mud, comprising the following steps:

[0025] The black copper mud and lead sulfate are mixed to obtain a mixture; the mixture is smelted to obtain a dearsenification residual product and a volatile condensation product; the dearsenification residual product comprises elemental Cu and PbS, and the volatile condensation product comprises As2O3;

[0026] The dearsenification residual product is subjected to vacuum distillation separation to obtain elemental Cu.

[0027] In the application, all the preparation raw materials / components are commercially available products well known to those skilled in the art, unless otherwise specified.

[0028] The application mixes the black copper mud and lead sulfate to obtain a mixture; the mixture is smelted to obtain a dearsenification residual product and a volatile condensation product; the dearsenification residual product comprises elemental Cu and PbS, and the volatile condensation product comprises As2O3. In the application, the black copper mud is an arsenic-containing solid waste generated on the surface of the cathode copper in the copper refining process. The main component of the black copper mud is preferably Cu3As; the arsenic content in the black copper mud is preferably 10-30wt%, more preferably 10-20wt% or 25-30wt%; the copper content in the black copper mud is preferably 30-60wt%, more preferably 30-40wt% or 50-60wt%. The mass ratio of the black copper mud to the lead sulfate is preferably 1:0.4-0.6, which can be 1:0.5 or 1:0.6 in the embodiments. The application does not have special requirements for the specific implementation of the mixing of the black copper mud and lead sulfate. In the specific embodiments of the application, the mixing preferably comprises crushing and mixing. The application does not have special requirements for the specific implementation of the crushing and mixing. The average particle size of the mixture is preferably 75-90μm. In the application, before the mixture is smelted, the application preferably further comprises drying the mixture. The drying temperature is preferably 100-110℃, and the time is preferably 2-4h.

[0029] The mixture after drying is preferably placed in a smelting furnace for the smelting. The temperature of the smelting is preferably 300-800°C, and can be 600°C or 800°C in examples. The holding time of the smelting is preferably 30-130 min, and can be 60 min or 120 min in examples. The heating rate from room temperature to the temperature of the smelting is preferably 10-15°C / min, and can be 15°C / min in examples. In the present application, the lead sulfate is directed to oxidize the black copper mud in the smelting process, to generate PbS and As2O3; then the As2O3 vapor is separated from Cu and PbS by taking advantage of the different saturated vapor pressures of Cu, PbS and As2O3, to complete the arsenic removal of the black copper mud. By controlling the mass ratio of the copper mud and the lead sulfate, the present application is more conducive to the directed oxidation of the lead sulfate to the black copper mud in the smelting process, and by controlling the operation parameters of the smelting, high-purity elemental Cu can be obtained. In the present application, the smelting directly generates As2O3 vapor, and the As2O3 volatilization product is obtained after condensation of the As2O3 vapor. The arsenic removal residual product preferably comprises elemental Cu and PbS.

[0030] After obtaining the arsenic removal residual product, the present application separates the arsenic removal residual product by vacuum distillation, to obtain elemental Cu. In the present application, the vacuum distillation is preferably performed in a vacuum furnace. The conditions of the vacuum distillation preferably include: the distillation pressure is preferably 1-1000 Pa, and can be 10 Pa or 5 Pa in examples; the distillation temperature is preferably 500-800°C, and can be 500°C or 600°C in examples; the holding time is preferably 30-120 min, and can be 30 min or 60 min in examples. The heating rate from room temperature to the distillation temperature is preferably 10-15°C / min, and can be 15°C / min in examples. In the present application, by taking advantage of the difference in the saturated vapor pressures of elemental Cu and PbS, the separation of elemental Cu and PbS is realized in the vacuum distillation.

[0031] In the present application, the purity of the elemental Cu is preferably >98%. The elemental Cu is preferably used as a raw material for copper refining, and is returned to the copper refining system. The vacuum distillation preferably also generates PbS vapor, and PbS is obtained after condensation of the PbS vapor. The PbS is used as a raw material for lead smelting.

[0032] In summary, the present application realizes the removal of arsenic and the recovery of metallic copper (in the form of elemental Cu) by using low-temperature directed oxidation of lead sulfate to black copper mud.

[0033] In order to further illustrate the present application, the technical solutions provided by the present application are described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present application.

[0034] Example 1

[0035] Take the black copper mud of a domestic copper smelter as an example, the main elements and their mass percentages are Cu 50-60wt%, As 25-30wt%, and the main component is Cu3As. According to the mass ratio of black copper mud and lead sulfate of 1:0.5, the mixed material with an average particle size of 75-90μm is obtained by mixing the materials, and the mixed material is placed in a drying box at a temperature of 110℃ for drying for 4h; the dried material block is placed in a smelting furnace; the temperature is raised from room temperature to 600℃ at a rate of 15℃ / min, and the temperature is kept for 60min, and the product is the dearsenization residual product of metal Cu and PbS and the volatilization condensation product of As2O3. Then, the dearsenization residual product of metal Cu and PbS is volatilized under vacuum conditions, a certain amount of dearsenization residual product of metal Cu and PbS is weighed in a vacuum furnace, the system pressure is controlled at 10Pa, the temperature is raised from room temperature to 500℃ at a rate of 15℃ / min, and the temperature is kept for 30min, and according to the difference in saturated vapor pressure, PbS in the dearsenization residual product of metal Cu and PbS is volatilized under vacuum to realize separation; after the above method, the recovery rate of Cu reaches 96.23%, the purity reaches 98.45%, which meets the purity standard of copper refining; the removal rate of lead sulfide is 99.30%; the removal rate of arsenic is 95.78%, and the purity of arsenic oxide is 99.30%.

[0036] Example 2

[0037] Take the black copper mud of a domestic copper smelter as an example, the main elements and their mass percentages are Cu 50-60wt%, As 25-30wt%, and the main component is Cu3As. According to the mass ratio of black copper mud and lead sulfate of 1:0.6, the mixed material with an average particle size of 75-90μm is obtained by mixing the materials, and the mixed material is placed in a drying box at a temperature of 110℃ for drying for 4h; the dried material block is placed in a smelting furnace; the temperature is raised from room temperature to 800℃ at a rate of 15℃ / min, and the temperature is kept for 120min, and the product is the dearsenization residual product of metal Cu and PbS and the volatilization condensation product of As2O3. Then, the dearsenization residual product of metal Cu and PbS is volatilized under vacuum conditions, a certain amount of dearsenization residual product of metal Cu and PbS is weighed in a vacuum furnace, the system pressure is controlled at 5Pa, the temperature is raised from room temperature to 600℃ at a rate of 15℃ / min, and the temperature is kept for 60min, and according to the difference in saturated vapor pressure, PbS in the dearsenization residual product of metal Cu and PbS is volatilized under vacuum to realize separation; after the above method, the recovery rate of Cu reaches 98.23%, the purity reaches 99.13%, which meets the purity standard of copper refining; the removal rate of lead sulfide is 99.80%; the removal rate of arsenic is 98.23%, and the purity of arsenic oxide is 99.42%.

[0038] Comparative Example 1

[0039] Taking black copper mud of a domestic copper smelting plant as an example, the main components and their mass percentages are Cu 50-60wt%, As 25-30wt%, and the main component is Cu3As. According to the mass ratio of black copper mud to lead sulfate of 1:0.2, the materials are mixed to obtain a mixture with an average particle size of 75-90 μm, and the mixture is placed in a drying box at a temperature of 110°C for 4h; the dried material is placed in a smelting furnace; the temperature is raised from room temperature to 800°C at a rate of 15°C / min, and the temperature is maintained for 120 min; the product is the dearsenization residue of metallic Cu and PbS and the volatilization condensation product of As2O3. Then, the dearsenization residue of metallic Cu and PbS is volatilized under vacuum conditions; a certain amount of the dearsenization residue of metallic Cu and PbS is weighed and placed in a vacuum furnace, the system pressure is controlled at 5 Pa, the temperature is raised from room temperature to 600°C at a rate of 15°C / min, and the temperature is maintained for 60 min; according to the difference in saturated vapor pressure, the PbS in the dearsenization residue of metallic Cu and PbS is volatilized under vacuum to achieve separation; after the above method, the recovery rate of Cu reaches 97.64%, the purity reaches 10.06%, the removal rate of lead sulfide is 99.80%, and the removal rate of arsenic is 12.05%, and the purity of arsenic oxide is 99.38%.

[0040] The method provided in Comparative Example 1 is compared with the method provided in Example 3; in Comparative Example 1, the mass ratio of black copper mud to lead sulfate is set to 1:0.2, which will seriously affect the removal rate of arsenic, and the purity of elemental Cu obtained is reduced to 10.06%.

[0041] From the above examples, it can be seen that the black copper mud and lead sulfate are mixed and then smelted in the present application. The PbSO4 is directed to oxidize Cu3As to generate As2O3, Cu and PbS, and at the same time, according to the difference in saturated vapor pressure, Cu and PbS do not volatilize and remain in the residue, and As is condensed in the condensation plate in the form of As2O3 vapor, realizing the separation of Cu and As. The method provided in the present application realizes the effective separation of copper and arsenic in high-arsenic copper hazardous waste-black copper mud, and the generated PbS and Cu can be directly returned to the copper refining system after being separated by vacuum distillation, realizing the comprehensive utilization of valuable elements; the present application realizes the low-temperature short-flow dearsenization and copper extraction of copper smelting black copper mud, the process flow is short, the operation is simple, the resource recovery rate is improved, and it has good application prospect.

[0042] Although the above examples have made a detailed description of the present application, it is only a part of the embodiments of the present application, not all the embodiments, and other embodiments can be obtained under the premise of no creativity according to the present embodiments, which all belong to the protection scope of the present application.

Claims

1. A method for dearsenifying and copper extraction from black copper mud by short process, characterized in that, The method comprises the following steps: mixing black copper mud and lead sulfate to obtain a mixture; and smelting the mixture to obtain a dearsenification residual product and a volatile condensation product; the dearsenification residual product comprises elemental Cu and PbS, and the volatile condensation product comprises As2O3; vacuum distillation separation of the dearsenification residual product to obtain elemental Cu.

2. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1, characterized in that, The smelting temperature is 300-800 ℃, and the holding time is 30-130 min.

3. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1 or 2, characterized in that, The temperature rising rate from room temperature to the smelting temperature is 10-15 ℃ / min.

4. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1, characterized in that, The main component of the black copper mud is Cu3As; the arsenic content in the black copper mud is 10-30 wt%, and the copper content is 30-60 wt%.

5. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1 or 4, characterized in that, The mass ratio of the black copper mud to the lead sulfate is 1:0.4-0.

6.

6. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1, characterized in that, The average particle size of the mixture is 75-90 μm; before smelting, the mixture is dried at a temperature of 100-110 ℃ for 2-4 h.

7. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1, characterized in that, The vacuum distillation separation conditions include a distillation pressure of 1-1000 Pa, a distillation temperature of 500-800 ℃, a holding time of 30-120 min, and a temperature rising rate from room temperature to the distillation temperature of 10-15 ℃ / min.

8. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1, characterized in that, The purity of the elemental Cu is >98%.

9. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1 or 8, characterized in that, The elemental Cu is used as a raw material for copper refining.

10. The method for dearsenifying and copper extraction from black copper mud in short process according to claim 1, characterized in that, The vacuum distillation separation also obtains PbS vapor, which is condensed and used as a raw material for lead smelting.

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