Method for short-process arsenic removal and copper extraction of black copper sludge

Abstract

The invention belongs to the technical field of metal smelting, and particularly relates to a short-process arsenic removal and copper extraction method for black copper sludge. The preparation method comprises the following steps: mixing black copper sludge and lead sulfate to obtain a mixture; smelting the mixture to obtain an arsenic-removed residual product and a volatile condensation product; the arsenic removal residual product comprises simple substances Cu and PbS, and the volatilization condensation product comprises As2O3; and carrying out vacuum distillation separation on the arsenic-removed residual product to obtain the simple substance Cu. According to the method, the black copper sludge and the lead sulfate are mixed and then smelted, so that Cu3As is directionally oxidized by PbSO4 to generate As2O3, Cu and PbS, simple substance Cu can be directly recycled from the black copper sludge through a two-step short process, and meanwhile, comprehensive utilization of valuable elements is realized; and the method has the characteristics of short process for recovering the elemental copper, simplicity in operation, high efficiency, economy, strong operability and the like, and is easy for industrial application.

Description

Technical Field

[0001] The invention belongs to the technical field of metal smelting, and particularly relates to a method for removing arsenic from black copper mud and extracting copper in a short process. Background Art

[0002] During the process of electrolytic copper removal and impurity removal, impurities such as As, Sb, and Bi in the copper electrolyte will precipitate at the cathode together with Cu. The mud-like substances (containing Cu, As, Sb, Bi, Pb, etc.) produced on the cathode are called black copper mud. The arsenic content in black copper mud is between 10 and 40wt%, which will not only seriously affect the quality of cathode copper, but also pose a threat to the safety of the surrounding environment. The copper content in black copper mud is 30 to 60wt%, which has considerable economic value. Black copper mud can be treated by acid method, alkali method or electrolysis method to recover the valuable metals therein, so as to achieve resource utilization and harmlessness. Black copper mud can also be returned to fire refining treatment to maximize the use of valuable metals therein, but there are problems such as arsenic accumulation and occupation of production capacity.

[0003] The research on arsenic removal from black copper mud mainly includes pyro-arsenic removal and wet-arsenic removal. Among them, the principle of pyro-arsenic removal from black copper mud is to utilize the property of As2O3 being easy to volatilize under high temperature conditions, and to separate the arsenic in the waste slag in the form of As2O3 by high-temperature roasting of arsenic-containing waste slag, thereby separating arsenic from other valuable metals to achieve arsenic removal. The advantages of pyro-arsenic removal are mature technology, wide application range and simple process flow. The principle of wet-arsenic removal from black copper mud is to leach arsenic in the form of arsenate, arsenite and thioarsenite. Among them, acid leaching arsenic removal is simple and easy, has good selectivity and high arsenic leaching rate for high-arsenic copper ores, and can also achieve arsenic solidification during leaching.

[0004] Currently, the treatment of black copper mud has become an urgent problem that copper smelting enterprises need to deal with, but the above-mentioned existing treatment methods cannot directly obtain elemental copper. Summary of the invention

[0005] The object of the present invention is to provide a method for removing arsenic and extracting copper from black copper mud in a short process. The method provided by the present invention can directly extract elemental copper from the black copper mud while achieving arsenic removal, and the process section of recovering elemental copper is more suitable for industrial application.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for removing arsenic from black copper mud in a short process and extracting copper, comprising the following steps:

[0008] Mixing black copper mud and lead sulfate to obtain a mixture; smelting the mixture to obtain a dearsenicating residual product and a volatilization condensation product; the dearsenicating residual product includes elemental Cu and PbS, and the volatilization condensation product includes As2O3;

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

[0010] Preferably, the smelting temperature is 300-800° C. and the holding time is 30-130 min.

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

[0012] Preferably, the main component of the black copper mud is Cu3As; the arsenic content in the black copper mud is 10-30wt%, and the copper content 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 75-90 μm; before the mixture is smelted, the mixture is dried at a temperature of 100-110° C. for 2-4 hours.

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

[0016] Preferably, the purity of the single substance Cu is greater than 98%.

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

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

[0019] The present invention provides a method for extracting copper from black copper mud by short-process arsenic removal, comprising the following steps: mixing black copper mud and lead sulfate to obtain a mixture; smelting the mixture to obtain a arsenic removal residual product and a volatilization condensation product; the arsenic removal residual product includes elemental Cu and PbS, and the volatilization condensation product includes As2O3; and separating the arsenic removal residual product by vacuum distillation to obtain elemental Cu. The present invention mixes black copper mud and lead sulfate and then smelts them. PbSO4 directional oxidation of Cu3As to generate As2O3, Cu and PbS is achieved, and at the same time, according to the difference in saturated vapor pressure, Cu and PbS are not volatilized and remain in the residue to obtain a arsenic removal residual product; As is removed in the form of As2O3 vapor to form a volatilization condensation product, thereby achieving the separation of Cu element and As element in black copper mud. The present invention achieves the effective separation of copper and arsenic in high-arsenic copper hazardous waste-black copper mud through smelting; then the separation of PbS and Cu is achieved only by vacuum distillation separation, and the elemental Cu product can be directly obtained. The method provided by the present invention can directly recover elemental Cu from black copper mud through a two-step short process, and realizes the comprehensive utilization of valuable elements at the same time; and the process for recovering elemental copper is short, the operation is simple, and it has the characteristics of high efficiency, economy and strong operability, and is easy to be industrially applied.

[0020] Furthermore, in the present invention, the smelting temperature is 300-800° C. The present invention realizes effective arsenic removal of black copper mud under low temperature conditions by controlling the smelting temperature to 300-800° C., has the characteristics of environmental protection, economy and strong operability, and is easy to be industrially applied.

[0021] Furthermore, in the present invention, the purity of the elemental Cu is greater than 98%; the elemental Cu is used as a raw material for copper refining. The elemental Cu separated by the present invention has high purity and can be directly returned to the copper refining system, thus realizing the comprehensive utilization of valuable elements.

[0022] The results of the examples show that the method for extracting copper from black copper mud by short-process arsenic removal provided by the present invention has a Cu recovery rate higher than 95% and a purity higher 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 oxide is higher than 99%, and the direct recovery rate of As is higher than 90%. In summary, the method for extracting copper from black copper mud by short-process arsenic removal provided by the present invention realizes the low-temperature short-process arsenic removal and copper extraction of black copper mud in copper smelting, has a short process flow, is simple to operate, improves the resource recovery rate, and has a good application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flow chart of a method for removing arsenic and extracting copper from black copper mud in a short process provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention provides a method for removing arsenic from black copper mud in a short process and extracting copper, comprising the following steps:

[0025] Mixing black copper mud and lead sulfate to obtain a mixture; smelting the mixture to obtain a dearsenicating residual product and a volatilization condensation product; the dearsenicating residual product includes elemental Cu and PbS, and the volatilization condensation product includes As2O3;

[0026] The dearsenication residual product is separated by vacuum distillation to obtain elemental Cu.

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

[0028] The present invention mixes black copper mud and lead sulfate to obtain a mixture; the mixture is smelted to obtain a dearsenification residual product and a volatilization condensation product; the dearsenification residual product includes elemental Cu and PbS, and the volatilization condensation product includes As2O3. In the present invention, the black copper mud is an arsenic-containing solid waste generated on the surface of cathode copper during copper refining. 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, and can be 1:0.5 or 1:0.6 in the embodiment. The present invention has no special requirements for the specific implementation of the mixing of the black copper mud and the lead sulfate. In a specific embodiment of the present invention, the mixing preferably includes crushing and mixing. The present invention has no special requirements for the specific implementation of the crushing and mixing. The average particle size of the mixture is preferably 75 to 90 μm. In the present invention, before the mixture is smelted, the present invention preferably further comprises: drying the mixture. The drying temperature is preferably 100 to 110° C., and the drying time is preferably 2 to 4 hours.

[0029] The present invention preferably places the dried mixture in a smelting furnace for smelting. The smelting temperature is preferably 300-800°C, and can be 600°C or 800°C in the embodiment. The holding time of the smelting is preferably 30-130min, and can be 60min or 120min in the embodiment. The heating rate from room temperature to the smelting temperature is preferably 10-15°C / min, and can be 15°C / min in the embodiment. In the present invention, the directional oxidation of black copper mud by lead sulfate is achieved during the smelting process to generate PbS and As2O3; then, the As2O3 vapor is separated from Cu and PbS by utilizing the difference in saturated vapor pressures of Cu, PbS and As2O3, and the dearsenicization of black copper mud is completed. The present invention is more conducive to the directional oxidation of black copper mud by lead sulfate during the smelting process by controlling the mass ratio of the copper mud and the lead sulfate, and at the same time, the operating parameters of the smelting are controlled to obtain high-purity elemental Cu. In the present invention, the smelting directly obtains As2O3 vapor, and the As2O3 volatiles are condensed to obtain volatile condensation products. The arsenic removal residual products preferably include elemental Cu and PbS.

[0030] After obtaining the dearsenication residual product, the present invention performs vacuum distillation separation on the dearsenication residual product to obtain elemental Cu. In the present invention, the vacuum distillation separation is preferably carried out in a vacuum furnace. The conditions of the vacuum distillation separation preferably include: the distillation pressure is preferably 1-1000Pa, and can be 10Pa or 5Pa in the embodiment; the distillation temperature is preferably 500-800°C, and can be 500°C or 600°C in the embodiment; the insulation time is preferably 30-120min, and can be 30min or 60min in the embodiment. The heating rate from room temperature to the distillation temperature is preferably 10-15°C / min, and can be 15°C / min in the embodiment. In the present invention, during the vacuum distillation separation process, the separation of elemental Cu and PbS is achieved by the difference in the saturated vapor pressures of elemental Cu and PbS.

[0031] In the present invention, the purity of the single substance Cu is preferably greater than 98%. The single substance Cu is preferably used as a raw material for copper refining and returned to the copper refining system. The vacuum distillation separation preferably also obtains PbS vapor, and the PbS vapor is condensed to obtain PbS. The PbS is used as a raw material for lead smelting.

[0032] In summary, the present invention adopts lead sulfate to directional oxidize black copper mud at low temperature to achieve the removal of arsenic and the recovery of metallic copper (directly in the form of Cu element).

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

[0034] Example 1

[0035] Taking the black copper mud of a domestic copper smelter as an example, the main elements and their mass percentages are Cu50-60wt%, 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 materials are mixed to obtain a mixture with an average particle size of 75-90μm, and the mixture is placed in a drying oven at a temperature of 110℃ for drying for 4h; the dried material blocks are placed in smelting; the temperature is raised from room temperature to 600℃ at a heating rate of 15℃ / min, and the temperature is kept for 60min. The products are the dearsenicization residual products of metal Cu and PbS and the volatilization and condensation products of As2O3. Then, the dearsenication residual products of metal Cu and PbS are volatilized under vacuum conditions, a certain amount of the dearsenication residual products of metal Cu and PbS are weighed and placed in a vacuum furnace, the system pressure is controlled to be 10Pa, the temperature is increased from room temperature to 500°C at a heating rate of 15°C / min, and the temperature is kept for 30 minutes. According to the difference in saturated vapor pressure, PbS in the dearsenication residual products of metal Cu and PbS is separated by vacuum volatilization; after being treated by the above method, the recovery rate of Cu reaches 96.23%, and the purity reaches 98.45%, which meet 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] Taking the black copper mud of a domestic copper smelter as an example, the main elements and their mass percentages are Cu50-60wt%, 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 materials are mixed to obtain a mixture with an average particle size of 75-90μm, and the mixture is placed in a drying oven at a temperature of 110℃ for drying for 4h; the dried material blocks are placed in smelting; the temperature is raised from room temperature to 800℃ at a heating rate of 15℃ / min, and the temperature is kept for 120min. The products are the dearsenicization residual products of metal Cu and PbS and the volatilization and condensation products of As2O3. Then, the dearsenication residual products of metal Cu and PbS are volatilized under vacuum conditions, a certain amount of the dearsenication residual products of metal Cu and PbS are weighed and placed in a vacuum furnace, the system pressure is controlled to 5Pa, the temperature is increased from room temperature to 600°C at a heating rate of 15°C / min, and the temperature is kept for 60 minutes. According to the difference in saturated vapor pressure, PbS in the dearsenication residual products of metal Cu and PbS is separated by vacuum volatilization; after being treated by the above method, the recovery rate of Cu reaches 98.23%, and the purity reaches 99.13%, which meet 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 the black copper mud of a domestic copper smelter as an example, the main components and their mass percentages are Cu50-60wt%, As 25-30wt%, and the main component is Cu3As. According to the mass ratio of black copper mud and lead sulfate of 1:0.2, the materials are mixed to obtain a mixture with an average particle size of 75-90μm, and the mixture is placed in a drying oven at a temperature of 110℃ for drying for 4h; the dried material blocks are placed in smelting; the temperature is raised from room temperature to 800℃ at a heating rate of 15℃ / min, and the temperature is kept for 120min. The products are the dearsenicization residual products of metal Cu and PbS and the volatilization and condensation products of As2O3. Then, the dearsenication residual products of metal Cu and PbS are volatilized under vacuum conditions, a certain amount of the dearsenication residual products of metal Cu and PbS are weighed and placed in a vacuum furnace, the system pressure is controlled to 5Pa, the temperature is increased from room temperature to 600°C at a heating rate of 15°C / min, and the temperature is kept for 60 minutes. According to the difference in saturated vapor pressure, PbS in the dearsenication residual products of metal Cu and PbS is separated by vacuum volatilization; after being treated by the above method, the recovery rate of Cu reaches 97.64% and the purity reaches 10.06%; the removal rate of lead sulfide is 99.80%; the removal rate of arsenic is 12.05%, and the purity of arsenic oxide is 99.38%.

[0040] Compared with the method provided in Example 3, the method provided in Comparative Example 1 has a mass ratio of black copper mud to lead sulfate of 1:0.2, which seriously affects the removal rate of arsenic, and the purity of the obtained elemental Cu is reduced to 10.06%.

[0041] From the above embodiments, it can be known that the present invention mixes black copper mud and lead sulfate and then smelts them. PbSO4 is used to directional oxidize Cu3As to generate As2O3, Cu and PbS. At the same time, according to the difference in saturated vapor pressure, Cu and PbS do not volatilize and remain in the residue. As condenses in the condensation plate in the form of As2O3 vapor, thereby achieving the separation of Cu and As. The method provided by the present invention realizes the effective separation of copper and arsenic in high-arsenic copper hazardous waste - black copper mud. At the same time, the generated PbS and Cu can be directly returned to the copper refining system after separation by vacuum distillation, thereby achieving the comprehensive utilization of valuable elements. The present invention realizes the low-temperature short-process arsenic removal and copper extraction of black copper mud in copper smelting, with a short process flow, simple operation, and improved resource recovery rate, and has a good application prospect.

[0042] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for removing arsenic from black copper mud in a short process, characterized in that: The following steps are involved: Mixing black copper mud and lead sulfate to obtain a mixture; smelting the mixture to obtain a dearsenicating residual product and a volatilization condensation product; the dearsenicating residual product includes elemental Cu and PbS, and the volatilization condensation product includes As2O3; The dearsenication residual product is separated by vacuum distillation to obtain elemental Cu.

2. The method for removing arsenic from black copper mud in a short process according to claim 1, characterized in that: The smelting temperature is 300-800° C. and the heat preservation time is 30-130 minutes.

3. The method for removing arsenic from black copper mud in a short process according to claim 1 or 2, characterized in that: The heating rate from room temperature to the melting temperature is 10-15°C / min.

4. The method for removing arsenic from black copper mud in a 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 10-30wt%, and the copper content is 30-60wt%.

5. The method for removing arsenic from black copper mud in a 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 removing arsenic from black copper mud in a short process according to claim 1, characterized in that: The average particle size of the mixture is 75-90 μm. Before the mixture is smelted, the mixture is dried at a temperature of 100-110° C. for 2-4 hours.

7. The method for removing arsenic from black copper mud in a short process according to claim 1, characterized in that: The conditions for vacuum distillation separation include: distillation pressure of 1-1000 Pa; distillation temperature of 500-800° C., insulation time of 30-120 min; heating rate from room temperature to the distillation temperature of 10-15° C. / min.

8. The method for removing arsenic from black copper mud in a short process according to claim 1, characterized in that: The purity of the single substance Cu is greater than 98%.

9. The method for removing arsenic from black copper mud in a short process according to claim 1 or 8, characterized in that: The single substance Cu is used as a raw material for copper refining.

10. The method for removing arsenic from black copper mud in a short process according to claim 1, characterized in that: The vacuum distillation separation also obtains PbS vapor, which is used as a raw material for lead smelting after condensation.

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