A method for treating high-arsenic copper-containing materials

Abstract

This invention relates to the field of chemical metallurgy, and in particular to a method for treating high-arsenic copper-containing materials. The method includes the following steps: S1, acid leaching of copper smelting slag and white smoke dust, followed by solid-liquid separation to obtain acid-leached slag and acid-leached solution; S2, mixing the acid-leached solution with arsenic sulfide slag, performing a copper precipitation reaction, followed by solid-liquid separation to obtain copper-precipitated slag and copper-precipitated liquid; S3, oxygen pressure leaching of the copper-precipitated liquid, followed by solid-liquid separation to obtain oxygen-leached slag and oxygen-leached solution; S4, mixing the oxygen-leached solution with steel mill flue dust, stirring until the pH reaches 5-5.4, followed by solid-liquid separation to obtain goethite slag and iron-removed liquid; wherein, the goethite slag obtained in step S4 is returned to the oxygen pressure leaching process in step S3, and the oxygen pressure leaching conditions are: temperature 150-170℃, pressure 1-1.4 MPa, oxygen partial pressure 0.5-0.8 MPa, and time 3-4 h.

Description

Technical Field

[0001] This invention relates to the field of chemical and metallurgical technology, and in particular to a method for processing copper-containing materials with high arsenic content. Background Technology

[0002] The white smoke ash and arsenic sulfide slag generated during copper pyrometallurgical processes not only contain abundant valuable metals such as Cu, Zn, Pb, and Bi, but also a large amount of the hazardous metal As. Therefore, they are explicitly listed as Category HW48 in the National Hazardous Waste List. Due to their unique chemical composition and potential environmental hazards, these wastes face strict regulatory and treatment requirements. Because the legal sales channels for these hazardous solid wastes are relatively narrow, and the export process may pose high environmental risks, their prices in the valuable metals market are severely suppressed. This undoubtedly causes economic losses for copper smelting enterprises, limiting their profitability and sustainable development. Furthermore, to effectively recover valuable copper from copper smelting slag, copper smelters must adopt a series of cumbersome steps: the smelting slag must first undergo two roughing processes to remove most impurities, followed by three fine cleaning processes for further purification, and finally three sweeping processes to ensure recovery efficiency. This entire process is lengthy and complex, and the copper recovery rate from the smelting slag is less than 90%. Therefore, how to efficiently and safely process various intermediate products in the copper smelting process is the key to reducing costs and improving economic efficiency for copper smelting enterprises.

[0003] In related patents, arsenic sulfide slag is used to sulfide-precipitate copper in flue gas acid leaching solution. Ferrous sulfate (FeSO4) is added to the copper-precipitated solution, and the reaction is carried out under oxygen pressure to generate highly stable arsenic trioxide (FeAsO4). However, a large amount of sulfuric acid is generated during the arsenic precipitation process. This excess sulfuric acid needs to be neutralized, resulting in a large amount of neutralization slag, which requires further treatment. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a method for processing high-arsenic copper-containing materials. This invention aims to achieve the goal of turning waste into treasure and promoting high-quality internal resource recycling through a short-process, efficient treatment of intermediate materials in the copper smelting process.

[0005] A method for processing high-arsenic copper-containing materials according to a first aspect embodiment of the present invention includes the following steps:

[0006] S1. After acid leaching of smelting slag and white smoke dust, solid-liquid separation is performed to obtain acid leaching residue and acid leaching solution;

[0007] S2. The acid leaching solution is mixed with arsenic sulfide slag, and after copper precipitation reaction, the solid and liquid are separated to obtain copper precipitation slag and copper precipitation liquid.

[0008] S3. After oxygen pressure leaching of the copper-plated liquid, solid-liquid separation is performed to obtain oxygen leaching residue and oxygen leaching liquid.

[0009] S4. Mix the oxygen leaching solution with steel plant flue dust and stir until the pH reaches 5-5.4. Then, separate the solid and liquid to obtain goethite slag and iron-removed liquid.

[0010] The goethite slag obtained in step S4 is returned to the oxygen pressure leaching process in step S3.

[0011] The oxygen pressure leaching temperature is 150~170℃, the oxygen pressure leaching pressure is 1~1.4MPa, the oxygen partial pressure is 0.5~0.8MPa, and the oxygen pressure leaching reaction time is 3~4h.

[0012] In step S1 of this invention, copper is recovered from copper smelting slag through a short process by co-processing copper smelting slag and white smoke dust. At the same time, the high Fe content in the copper smelting slag provides an iron source for oxygen pressure arsenic removal.

[0013] In some embodiments of the present invention, the smelting slag comprises, by mass percentage, the following main components: Cu 0.76~4.58 wt%, Fe 40.92~45.99 wt%, Zn 4~8 wt%, Pb 0.5~3 wt%, As 0.01~0.2 wt%, Bi 0.01~0.1 wt%, and S 0.5~2 wt%. Preferably, the smelting slag comprises, by mass percentage, the following main components: Cu 0.76~2.58 wt%, Fe 42.92~45.99 wt%, Zn 4~6 wt%, Pb 0.5~1.5 wt%, As 0.05~0.2 wt%, Bi 0.01~0.05 wt%, and S 0.5~1.2 wt%. More preferably, the smelting slag comprises the following main components by mass percentage: Cu 1.76~2.58 wt%, Fe 42.92~44.99 wt%, Zn 4~5 wt%, Pb 0.5~1 wt%, As 0.05~0.1 wt%, Bi 0.02~0.05 wt%, and S 0.6~1 wt%.

[0014] In some embodiments of the present invention, the smelting slag is copper smelting slag, and its 200-mesh sieve passing rate is ≥90% (by weight).

[0015] In some embodiments of the present invention, the white smoke dust includes arsenic-containing copper white smoke dust.

[0016] In some embodiments of the present invention, the white smoke dust comprises, by weight percentage, the following main components: Cu 2-8 wt%, Pb 5-20 wt%, Zn 5-20 wt%, Bi 0.5-4 wt%, As 4-15 wt%, Fe 0.1-3 wt%, and S 8-20 wt%. Preferably, the white smoke dust comprises, by weight percentage, the following main components: Cu 4-8 wt%, Pb 10-20 wt%, Zn 10-20 wt%, Bi 0.5-2 wt%, As 4-10 wt%, Fe 0.1-2 wt%, and S 10-20 wt%. More preferably, the white smoke dust comprises the following main components by mass percentage: Cu 4~6 wt%, Pb 15~20 wt%, Zn 15~20 wt%, Bi 0.5~1.5 wt%, As 5~8 wt%, Fe 0.3~1 wt%, and S 10~15 wt%.

[0017] In some embodiments of the present invention, the mass ratio of the white smoke dust to the smelting slag is 1:0.1~0.5, for example 1:0.1~0.4, 1:0.2~0.4, 1:0.2~0.3, 1:0.25~0.3, or 1:0.28.

[0018] In some embodiments of the present invention, the acid used in the acid leaching process is a sulfuric acid solution. In some embodiments of the present invention, the concentration of the acid solution can be 40-50 g / L. In some embodiments of the present invention, the total mass ratio of the white smoke dust and smelting slag to the volume ratio of the acid solution can be 1 kg : (6-8) L.

[0019] In some embodiments of the present invention, the acid leaching temperature is 80~90°C.

[0020] In some embodiments of the present invention, the acid leaching time is 0.5 to 2 hours.

[0021] In some embodiments of the present invention, the pH at the endpoint of the acidic leaching is 0.5 to 2, for example, 1.

[0022] In some embodiments of the present invention, after the acid leaching is completed, the temperature is lowered to below 70°C for solid-liquid separation.

[0023] In some embodiments of the present invention, the acid leaching residue includes lead-bismuth residue.

[0024] In some embodiments of the present invention, the arsenic sulfide slag comprises, by weight percentage, the following main components: As 8-60 wt% (e.g., 20-60 wt%, 30-60 wt%, 40-60 wt%, 50-60 wt%); S 15-40 wt% (e.g., 20-40 wt%, 25-40 wt%, 30-40 wt%, 30-35 wt%). Preferably, the arsenic sulfide slag comprises, by weight percentage, the following main components: As 50-60 wt%, S 30-35 wt%, Cu 0.5-1 wt%, Fe 0.1-0.5 wt%, Zn 0.1-0.5 wt%, Pb 0.5-1 wt%, Bi 0.02-0.1 wt%.

[0025] In some embodiments of the present invention, the arsenic sulfide slag has a 200-mesh sieve passing rate of ≥90% (by weight).

[0026] In some embodiments of the present invention, the mass ratio of the white smoke dust in step S1 to the arsenic sulfide slag in step S2 is 1:0.4~4, for example 1:0.5~3, 1:0.5~2, 1:1~2.5, 1:1.5~2.5.

[0027] In some embodiments of the present invention, the temperature of the copper plating reaction is 70~100℃, for example 70~75℃, 80~100℃, or 90~100℃.

[0028] In some embodiments of the present invention, the copper plating reaction time is 4-8 h, for example 2-4 h or 6-8 h.

[0029] In some embodiments of the present invention, the copper plating reaction includes, in sequence, a first-stage copper plating reaction and a second-stage copper plating reaction.

[0030] The two-stage copper precipitation reaction can recover as much copper as possible from copper smelting slag and white smoke dust, preventing copper from entering subsequent processes to form ferrous sulfate and finally being discharged as ferric arsenate slag, thus avoiding the waste of valuable metals.

[0031] Preferably, step S2 includes: mixing the acid leaching solution with arsenic sulfide slag, performing a first-stage copper precipitation reaction, and then separating the solid and liquid to obtain a first copper precipitation slag and a first copper precipitation post-liquid; mixing the first copper precipitation post-liquid with arsenic sulfide slag, performing a second-stage copper precipitation reaction, and then separating the solid and liquid to obtain a second copper precipitation slag and a second copper precipitation post-liquid; and returning the second copper precipitation slag to the first-stage copper precipitation reaction.

[0032] Preferably, the time for the first-stage copper plating reaction and the second-stage copper plating reaction are each 1 to 4 hours independently.

[0033] Preferably, the mass ratio of arsenic sulfide slag used in the first stage copper plating reaction to arsenic sulfide slag used in the second stage copper plating reaction is 6~10:1, for example 8~10:1.

[0034] In some embodiments of the present invention, the oxygen pressure leaching is carried out in an autoclave.

[0035] In some embodiments of the present invention, the conditions for oxygen pressure leaching are: reaction temperature of 155~165℃, pressure of 1.1~1.3MPa, and oxygen partial pressure of 0.5~0.7MPa.

[0036] By controlling the reaction temperature, pressure, oxygen partial pressure, and reaction duration in the autoclave, approximately 95% of arsenic and iron are converted into FeAsO4 and deposited, thus achieving simultaneous arsenic removal and iron removal.

[0037] In some embodiments of the present invention, the sulfuric acid concentration in the oxygen leaching solution is 30~35g / L.

[0038] In some embodiments of the present invention, the oxygen leaching residue includes ferric arsenate slag.

[0039] In some embodiments of the present invention, the steel mill flue dust comprises, by weight percentage, the following main components: Fe 10-30 wt% (e.g., 10-25 wt%, 10-20 wt%), Zn 30-60 wt% (e.g., 40-60 wt%, 50-60 wt%, 50-55 wt%). Preferably, the steel mill flue dust comprises, by weight percentage, the following main components: Fe 10-20 wt%, Zn 50-55 wt%, Pb 1-1.5 wt%, Cu ≤0.01 wt%.

[0040] In some embodiments of the present invention, the mass ratio of white smoke dust in step S1 to steel plant ash in step S4 is 1:0.8~5, for example 1:2~5, 1:3~5, 1:4~5, 1:4~4.5.

[0041] In some embodiments of the present invention, the stirring is carried out under conditions of oxygen-enriched air, wherein the oxygen concentration is 21-60%.

[0042] In some embodiments of the present invention, the stirring time is 4 to 6 hours, specifically, it can be 4 hours, 5 hours, or 6 hours.

[0043] In some embodiments of the present invention, the iron content in the final stirred liquid is controlled to be ≤40 mg / L, for example ≤30 mg / L or ≤20 mg / L.

[0044] In some embodiments of the present invention, the iron-removed liquid contains Zn ≥ 150 g / L, iron ≤ 20 mg / L, and arsenic ≤ 15 mg / L. After deep impurity removal, it can be sold externally or used to produce zinc sulfate heptahydrate products.

[0045] In some embodiments of the present invention, the solid-liquid separation can be carried out by means of filtration, pressure filtration, centrifugation, etc., for example, by pressure filtration.

[0046] According to some embodiments of the present invention, at least the following beneficial effects are achieved:

[0047] (1) This invention co-processes copper pyrometallurgical slag, white smoke dust and arsenic sulfide slag, which is a short-process hazardous waste treatment process. It achieves effective removal of arsenic greater than 93% or even 95% in the whole process, copper recovery rate greater than 92.5% or even 94%, zinc leaching rate greater than 98%, lead recovery rate greater than 92%, and bismuth recovery rate greater than 96%.

[0048] (2) Copper pyrometallurgical slag does not require flotation to recover copper. Instead, through synergistic treatment with white smoke dust, not only is the valuable metal copper in the slag effectively recovered, but also the harmful element arsenic is removed. Furthermore, the recovery rate of other valuable metals such as zinc, lead, and bismuth in the slag is maximized.

[0049] (3) By using arsenic sulfide slag as a reducing agent, the maximum utilization of arsenic sulfide slag resources is achieved. Furthermore, by employing secondary copper precipitation technology, the copper recovery rate in copper pyrometallurgical slag, white smoke dust, and arsenic sulfide slag can be consistently higher than 94%.

[0050] (4) Use the goethite method to remove iron, control the pH of the iron removal endpoint to 5~5.4. During the neutralization, hydrolysis and precipitation process, some arsenic in the solution will also precipitate out, ensuring that the liquid iron after iron removal is less than 20 mg / L and the arsenic is less than 15 mg / L.

[0051] (5) Resource utilization of iron (content up to 44%) in copper pyrometallurgical slag: Fe in the slag enters the solution through acid leaching. The iron-rich solution is used as an iron supplement in the process of treating arsenic sulfide slag in a high-pressure autoclave after copper precipitation by reduction of arsenic sulfide slag. This not only helps to effectively remove arsenic from arsenic sulfide slag, but also realizes the recycling of iron resources.

[0052] (6) Control the reaction temperature of the high pressure vessel to 150~170℃, maintain the pressure at 1~1.4MPa, set the oxygen partial pressure to 0.5~0.8MPa, and let the reaction last for 3~4h. ~95% of arsenic and iron are converted into FeAsO4 and deposited. At the same time as removing arsenic, the system removes iron.

[0053] (7) The goethite slag from the iron removal process is returned to the autoclave as an iron supplement for arsenic sulfide slag. By controlling the ratio of its iron source to that provided by copper smelting slag (e.g., about 1:0.8~1.1), the formation of alum slag in goethite can be avoided while ensuring the iron-arsenic molar ratio.

[0054] (8) This invention produces only one type of ferric arsenate slag (FeAsO4 content greater than 75%) for stockpiling; other filter residues can be sold externally at a price. The liquid after iron removal contains Zn ≥ 150 g / L, and after deep impurity removal, it can be sold externally or used to produce zinc sulfate heptahydrate products.

[0055] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0056] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0057] The following will describe the concept and technical effects of the present invention clearly and completely with reference to the embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0058] In the description of this invention, the use of terms such as "first," "second," etc., is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0059] The terms "preferred," "more preferably," etc., used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0060] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0061] Unless otherwise specified, "about" in this invention means that the allowable error is within ±2%.

[0062] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0063] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0064] The embodiments of the present invention employ a "acid leaching-secondary copper plating-oxygen pressure leaching" process, such as... Figure 1 As shown, the specific scheme is as follows: Pb, Zn, and Cu in white dust and smelting slag mainly exist in the form of oxides or sulfates, while As mainly exists in the form of As2O3. Arsenic sulfide slag is mainly composed of sulfides. This invention first acid-leaches the smelting slag and white dust, allowing Cu, Zn, Fe, and As in the smelting slag and white dust to enter the solution, while Pb, Bi, and other elements are enriched in the lead-bismuth slag (sold externally). The acid leaching solution serves as the mother liquor for secondary copper precipitation of the arsenic sulfide slag. The copper-precipitated slag is sold externally. The liquid after copper precipitation is pumped into a high-pressure reactor for treating arsenic sulfide slag, converting approximately 95% of the arsenic into stable ferric arsenate precipitate. The leachate is then mixed with steel mill flue dust for secondary iron removal, forming goethite slag. The goethite slag is returned to the pre-treatment tank of the high-pressure reactor as a secondary iron source for oxygen pressure leaching of the arsenic sulfide slag. After iron removal, the liquid undergoes deep impurity removal to recover Zn from the solution.

[0065] Example 1

[0066] The smelting slag used in this embodiment comprises the following main components by mass percentage: Fe 44wt%, As 0.09wt%, Cu 1.95wt%, Zn 4.78wt%, Pb 0.63wt%, Bi 0.04wt%, and S 0.88wt%.

[0067] The arsenic sulfide slag contains the following main components by mass percentage: Fe 0.26wt%, As 55.8wt%, Cu 0.68wt%, Zn 0.26wt%, Pb 0.58wt%, Bi 0.029wt%, and S 33.8wt%.

[0068] The white smoke dust comprises the following main components by mass percentage: Fe 0.5wt%, As 7.59wt%, Cu 5.25wt%, Zn 15.6wt%, Pb 16wt%, Bi 0.88wt%, and S 12.3%.

[0069] Steel mill flue dust comprises the following main components by weight percentage: Fe 15wt%, Cu 0.01wt%, Zn 52wt%, and Pb 1.12wt%.

[0070] This embodiment provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0071] (1) Crush and grind the smelting slag and arsenic sulfide slag until mineral particles accounting for 90% or more of the total mineral weight can pass through a 200-mesh sieve.

[0072] (2) The finely ground smelting slag, white dust, and 45 g / L sulfuric acid solution are mixed to form a slurry. The prepared slurry is then pumped into an acid leaching tank for reaction. The feeding rate of the white dust is 1 t / h, the feeding rate of the smelting slag is 0.28 t / h, and the feeding rate of the sulfuric acid solution is 8.61 m / h. 3 The reaction temperature in the acid leaching tank is controlled at 85℃ for 60 minutes per hour. After the reaction is complete, the final acid pH is 1. The material is then cooled to below 70℃ and pumped to a filter press for filtration. The filter residue is lead-bismuth slag, and the filtrate is acid leaching solution. The lead-bismuth slag can be sold externally, and the acid leaching solution is subsequently mixed with arsenic sulfide slag to form a slurry.

[0073] (3) The acid leaching solution and arsenic sulfide slag are added to the primary copper precipitation tank in a calculated ratio. The feeding rate of the arsenic sulfide slag is 0.4866 t / h, and the reaction temperature is controlled at approximately 90℃ for 4 hours. The slurry after primary copper precipitation is filtered, and the resulting copper slag (i.e., copper concentrate) is sold. The liquid after primary copper precipitation flows into the secondary copper precipitation tank, where 0.05 t / h of arsenic sulfide is added and the reaction is carried out continuously at 90℃ for 4 hours. The slurry after secondary copper precipitation is filtered, and the resulting secondary copper precipitation slag is returned to the primary copper precipitation tank after pulping. The liquid after secondary copper precipitation is pumped to an autoclave for arsenic removal.

[0074] (4) Control the reaction temperature of the high-pressure reactor to 160℃, maintain the pressure at 1.2MPa, set the oxygen partial pressure to 0.6MPa, and continue the reaction for 3 hours. After the reaction is completed, the material is discharged into the flash tank to achieve rapid cooling and depressurization, and then transferred to the regulating tank for further cooling. Finally, liquid-solid separation is carried out, and the produced ferric arsenate leaching residue (i.e. ferric arsenate slag) is stockpiled, while the high-pressure leachate is used for the next step.

[0075] (5) Add steel mill flue dust to the high-pressure leachate and introduce 35% oxygen-enriched air, then start stirring to remove iron. The feeding rate of the steel mill flue dust is 0.87 t / h, the reaction time is about 5 hours, the final liquid iron content is controlled at 20 mg / L, and the final pH is 5.2. After the reaction is completed, liquid-solid separation is performed. The resulting goethite slag is returned to the autoclave as an arsenic removal and iron supplementation agent, while the liquid after iron removal can be sold or used to produce zinc sulfate heptahydrate after deep impurity removal.

[0076] The components in the separated copper slag, ferric arsenate slag, lead-bismuth slag, and iron-removed liquid were detected, the generated amounts were counted, and the copper recovery rate, zinc leaching rate, and arsenic removal rate were calculated. The results are shown in Table 1.

[0077] Table 1

[0078]

[0079] Example 2

[0080] The smelting slag used in this embodiment comprises the following main components by mass percentage: Fe 44wt%, As 0.09wt%, Cu 1.95wt%, Zn 4.78wt%, Pb 0.63wt%, Bi 0.04wt%, and S 0.88wt%.

[0081] The arsenic sulfide slag contains the following main components by mass percentage: Fe 0.26wt%, As 55.8wt%, Cu 0.68wt%, Zn 0.26wt%, Pb 0.58wt%, Bi 0.029wt%, and S 33.8wt%.

[0082] The white dust comprises the following main components by mass percentage: Fe 0.78wt%, As 5.53wt%, Cu 4.69wt%, Zn 17.8wt%, Pb 18wt%, Bi 1.22wt%, and S 12.3wt%.

[0083] Steel mill flue dust comprises the following main components by weight percentage: Fe 15wt%, Cu 0.01wt%, Zn 52wt%, and Pb 1.12wt%.

[0084] This embodiment provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0085] (1) Crush and grind the smelting slag and arsenic sulfide slag until mineral particles accounting for 90% or more of the total mineral weight can pass through a 200-mesh sieve.

[0086] (2) The finely ground smelting slag, white dust, and 45 g / L sulfuric acid solution are mixed to form a slurry. The prepared slurry is then pumped into an acid leaching tank for reaction. The feeding rate of the white dust is 1 t / h, the feeding rate of the smelting slag is 0.28 t / h, and the feeding rate of the sulfuric acid solution is 9.63 m / h. 3 The reaction temperature in the acid leaching tank is controlled at 85℃ for 60 minutes per hour. After the reaction is complete, the final acid pH is 1, and the material is cooled to below 70℃. It is then pumped to a filter press for filtration, yielding lead-bismuth slag as the filter residue and acid leaching liquid as the filtrate. The lead-bismuth slag is sold externally, and the acid leaching liquid is subsequently mixed with arsenic sulfide slag to form a slurry.

[0087] (3) The acid leaching solution and arsenic sulfide slag are added to the primary copper precipitation tank in a calculated ratio. The feeding rate of the arsenic sulfide slag is 0.4866 t / h, and the reaction temperature is controlled at approximately 90℃. The reaction is carried out continuously for 4 hours. The slurry after primary copper precipitation is filtered, and the resulting copper slag (i.e., copper concentrate) is sold. The liquid after primary copper precipitation flows into the secondary copper precipitation tank, where 0.05 t / h of arsenic sulfide slurry is added and the reaction is carried out continuously at 90℃ for 4 hours. The slurry after secondary copper precipitation is filtered, and the resulting secondary copper precipitation slag is returned to the primary copper precipitation tank after pulping. The liquid after secondary copper precipitation is pumped to an autoclave for arsenic removal.

[0088] (4) Control the reaction temperature of the high-pressure reactor to 160℃, maintain the pressure at 1.2MPa, set the oxygen partial pressure to 0.6MPa, and continue the reaction for 3 hours. After the reaction is completed, the material is discharged into the flash tank to achieve rapid cooling and depressurization, and then transferred to the regulating tank for further cooling. Finally, liquid-solid separation is carried out, and the produced ferric arsenate leaching residue (i.e. ferric arsenate slag) is stockpiled, while the high-pressure leachate is used for the next step.

[0089] (5) Add steel mill flue dust to the high-pressure leachate and introduce 35% oxygen-enriched air, then start stirring to remove iron. The feeding rate of the steel mill flue dust is 0.874 t / h, the reaction time is about 5 hours, the final liquid iron content is controlled at 20 mg / L, and the final pH is 5.2. After the reaction is completed, liquid-solid separation is performed. The resulting goethite slag is returned to the autoclave as an arsenic removal and iron supplementing agent, while the liquid after iron removal can be sold or used to produce zinc sulfate heptahydrate after deep impurity removal.

[0090] The components of the separated copper slag, ferric arsenate slag, lead-bismuth slag, and iron-removed liquid were detected, the generated amounts were counted, and the copper recovery rate, zinc leaching rate, and arsenic removal rate were calculated. The results are shown in Table 2.

[0091] Table 2

[0092]

[0093] Example 3

[0094] This embodiment provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0095] The procedure was carried out with reference to Example 1, except that the concentration of the acid solution in the acid leaching process of step (2) was 35 g / L.

[0096] The composition of the separated acid leaching solution and copper slag was analyzed, the amount generated was counted, and the copper recovery rate was calculated.

[0097] The results showed that the copper recovery rate decreased to 92.5%.

[0098] Example 4

[0099] This embodiment provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0100] The procedure was carried out with reference to Example 1, except that the concentration of the acid solution in the acid leaching process of step (2) was 55 g / L.

[0101] The components of the separated acid leaching solution and copper slag were analyzed, the amount generated was counted, and the copper recovery rate and arsenic removal rate were calculated.

[0102] The results showed that copper arsenide was present in the copper slag. The copper recovery rate was 94.2%, but the arsenic removal rate decreased to 93.25%.

[0103] Example 5

[0104] This embodiment provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0105] The process was carried out with reference to Example 2, and the only difference from Example 2 was that the reaction time for oxygen pressure leaching in step (4) was 4 hours.

[0106] The components in the oxygen pressure leaching solution obtained by separation were detected, the steam flow rate during the oxygen pressure leaching process was counted, and the arsenic removal rate and energy consumption were calculated.

[0107] The results showed that the arsenic removal rate was 94.25%, but steam consumption increased by 5%, resulting in increased energy consumption and reduced economic efficiency.

[0108] Example 6

[0109] This embodiment provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0110] The process was carried out with reference to Example 2. The only difference between the steps in Example 2 and the steps in Example 2 is that the reaction temperature for oxygen pressure leaching in step (4) is 170°C and the oxygen partial pressure is 0.8 MPa.

[0111] The components in the oxygen pressure leaching solution obtained by separation were detected, the steam flow rate during the oxygen pressure leaching process was counted, and the arsenic removal rate and energy consumption were calculated.

[0112] The results showed that the arsenic removal rate was 94.51%, but steam consumption increased by 2%, oxygen partial pressure increased, energy consumption increased, and economic efficiency decreased.

[0113] Comparative Example 1

[0114] This comparative example provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0115] The process was carried out in accordance with Example 1, with the only difference from Example 1 being that in step (5), the high-pressure leachate was mixed with steel plant flue dust and 35% oxygen-enriched air was introduced and stirred until pH=4.5.

[0116] The components of the separated goethite and the iron-removed liquid were detected, the amount generated was counted, and the zinc leaching rate was calculated.

[0117] The results showed that goethite has strong water absorption and poor liquid-solid separation. Zinc in the solution precipitates out along with iron, and the zinc leaching rate decreases to 95.26%.

[0118] Comparative Example 2

[0119] This comparative example provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0120] The procedure was carried out in accordance with Example 1, with the only difference from Example 1 being that in step (5), the high-pressure leachate was mixed with steel plant flue dust and 35% oxygen-enriched air was introduced and stirred until pH=6.0.

[0121] The components of the separated goethite and the iron-removed liquid were detected, the amount generated was counted, and the zinc leaching rate was calculated.

[0122] The results showed that the goethite was in an enlarged state, which seriously affected the clarification and filtration performance of the leachate. After iron removal, the zinc ion concentration in the solution decreased to 145 g / L, and the zinc leaching rate decreased to 94.32%.

[0123] Comparative Example 3

[0124] This comparative example provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0125] The process was carried out with reference to Example 2, and the only difference from Example 2 was that the reaction time for oxygen pressure leaching in step (4) was 2 hours.

[0126] The components in the oxygen pressure leachate obtained by separation were detected, the amount generated was counted, and the arsenic removal rate was calculated.

[0127] The results showed that the arsenic removal rate decreased to 92.51%.

[0128] Comparative Example 4

[0129] This comparative example provides a method for the synergistic treatment of high-arsenic copper-containing materials, the specific steps of which are as follows:

[0130] The process was carried out with reference to Example 2. The only difference between the steps in Example 2 and the steps in Example 2 is that the reaction temperature for oxygen pressure leaching in step (4) is 150°C and the oxygen partial pressure is 0.2 MPa.

[0131] The components in the oxygen pressure leaching solution obtained by separation were detected, the steam flow rate during the oxygen pressure leaching process was counted, and the arsenic removal rate was calculated.

[0132] The results showed that the arsenic precipitation rate decreased to 92.87%.

[0133] The embodiments of the present invention have been described in detail above with reference to the examples. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for treating copper-containing materials with high arsenic content, characterized in that, Includes the following steps: S1. After acid leaching of smelting slag and white smoke dust, solid-liquid separation is performed to obtain acid leaching residue and acid leaching solution; S2. The acid leaching solution is mixed with arsenic sulfide slag, and after copper precipitation reaction, the solid and liquid are separated to obtain copper precipitation slag and copper precipitation liquid. S3. After oxygen pressure leaching of the copper-plated liquid, solid-liquid separation is performed to obtain oxygen leaching residue and oxygen leaching liquid. S4. Mix the oxygen leaching solution with steel plant flue dust and stir until the pH reaches 5-5.

4. Then, separate the solid and liquid to obtain goethite slag and iron-removed liquid. The goethite slag obtained in step S4 is returned to the oxygen pressure leaching process in step S3. The oxygen pressure leaching temperature is 150~170℃, the oxygen pressure leaching pressure is 1~1.4MPa, the oxygen partial pressure of the oxygen pressure leaching is 0.5~0.8MPa, and the oxygen pressure leaching reaction time is 3~4h. The smelting slag is copper smelting slag, and the white smoke dust is arsenic-containing copper white smoke dust.

2. The method according to claim 1, characterized in that, The acid leaching temperature is 80~90℃; and / or the acid leaching time is 0.5~2h.

3. The method according to claim 1, characterized in that, The acid leaching is carried out using an acid solution, wherein the concentration of the acid solution is 40-50 g / L; and / or, the total mass ratio of the smelting slag and white dust to the volume ratio of the acid solution is 1 kg: (6-8) L.

4. The method according to claim 1, characterized in that, The temperature of the copper plating reaction is 70~100℃; and / or the time of the copper plating reaction is 4~8 h.

5. The method according to claim 1, characterized in that, The copper plating reaction consists of a first-stage copper plating reaction and a second-stage copper plating reaction in sequence.

6. The method according to claim 5, characterized in that, The copper plating reaction includes: after the first stage of copper plating reaction is completed, solid-liquid separation is performed to obtain a first copper plating slag and a first copper plating post-liquid; the first copper plating post-liquid is mixed with arsenic sulfide, and after a second stage of copper plating reaction, solid-liquid separation is performed to obtain a second copper plating slag and a second copper plating post-liquid; the second copper plating slag is returned to the first stage of copper plating reaction.

7. The method according to claim 1, characterized in that, The arsenic sulfide slag comprises the following main components by mass percentage: As 8~60 wt%, S 15~40 wt%.

8. The method according to claim 1, characterized in that, The steel plant ash comprises the following main components by mass percentage: Fe 10~30 wt%, Zn 30~60 wt%.

9. The method according to claim 1, characterized in that, In step S4, stir until the final liquid contains ≤40mg / L of iron.

10. The method according to claim 1, characterized in that, The stirring is carried out under conditions of oxygen-enriched air.

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