Synergistic depletion treatment method for arsenic sulfide slag and copper slag and application

Abstract

The invention provides an arsenic sulfide slag and copper slag collaborative dilution treatment method and application, the method comprises the following steps: carrying out vulcanization reaction on arsenic sulfide slag and copper slag to obtain hot slag, and slowly cooling the hot slag to obtain slowly cooled slag; the slow cooling slag comprises a metal sulfonium phase and a slag phase which are well bounded, in the metal sulfonium phase, not less than 96% of metal sulfide is enriched to form particles with the particle size of more than 40 [mu] m, and the arsenic element in the arsenic sulfide slag is fixed in the slag phase; the moisture content in the arsenic sulfide slag is not greater than 1.5%, and the average particle size is not less than 200 meshes; the dosage mass ratio of the copper slag to the arsenic sulfide slag is 100: (3.5-5.5). According to the method provided by the invention, the arsenic sulfide slag is directly adopted as the copper slag depleting agent, the boundary of a metal sulfonium phase and a slag phase in the obtained slow cooling slag is clear through a depleting-slow cooling process, more than 96% of valuable metal sulfides such as copper, lead and zinc are enriched to form particles of more than 40 microns, the subsequent flotation process is very convenient, and comprehensive recovery of copper slag resources is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste treatment, and in particular to a method for collaborative depletion treatment of arsenic sulfide slag and copper slag and application thereof. Background Art

[0002] Copper slag and arsenic sulfide slag are two common waste products in non-ferrous metal smelting. Copper slag, a major byproduct of pyrometallurgical copper smelting, exhibits a significant slag yield ratio—2-3 tons of copper slag are produced for every ton of refined copper produced. The copper phase in the slag primarily consists of bornite, chalcocite, and metallic copper, while the iron phase occurs in the form of magnetite, fayalite, and amorphous silicates, which readily release heavy metal ions during natural weathering. With the widespread adoption of oxygen-enriched smelting technology, the loss of oxidized copper in the silicate matrix in copper slag has gradually increased. However, mainstream copper slag flotation processes are only effective in recovering mechanically entrained sulfide particles, with insufficient efficiency in recovering oxidized copper. Furthermore, elements such as lead, zinc, and iron present in the raw copper concentrate enter the slag phase as impurities during the smelting process. Existing processes often utilize an "open-circuit discard" model, resulting in the loss of significant iron, lead, and zinc resources through slag stockpiling.

[0003] The current copper slag resource recovery system faces a dual dilemma: on the one hand, high-value-added metals in copper slag are not fully extracted; on the other hand, the synergistic recovery technology for strategic metals such as lead, zinc, and iron has yet to be commercialized. Developing novel processes that combine enhanced dissociation of oxidized copper with the synergistic enrichment of multiple metals has become a key technological bottleneck in achieving full elemental resource recovery in copper smelting.

[0004] CN118813969A discloses a method for recovering valuable metals from copper slag, comprising the following steps: adding a composite depleting agent to hot copper slag at 1180-1320°C; slowly cooling the hot copper slag to room temperature and then standing for more than 35 hours to obtain self-pulverizing copper slag with a particle size of 1 mm-10 mm without conventional grinding; flotation of the self-pulverizing copper slag to further separate and recover metal sulfides, alloys and / or zinc ferrite; wherein the mass ratio of sodium sulfate to carbonaceous reducing agent in the composite depleting agent is 2-6:1; and the sulfur content in the composite depleting agent is 6-10 times the theoretical sulfur content required to completely sulfide all metal oxides in the copper slag.

[0005] CN118792512A discloses a hot slag chute and its application in recovering valuable metals in copper slag, comprising the following steps: allowing hot copper slag discharged from a slag outlet of a smelting system to flow into the hot slag chute from the side where a first curved baffle is located; adding a sulfide conditioning agent from the upper part of the opposite side of the first curved baffle in the hot slag chute and immersing it in the hot copper slag; the hot copper slag to which the sulfide conditioning agent is added passes through the curved baffle and a buffer column, enters a slag ladle and is slowly cooled to room temperature to obtain slowly cooled slag. ; The slowly cooled slag is subjected to grinding treatment and flotation treatment in sequence to obtain metal sulfides, alloys and / or zinc ferrite; wherein the sulfiding conditioning agent includes gypsum slag and a carbonaceous reducing agent, the composition of the carbonaceous reducing agent includes fixed carbon, the composition of the gypsum slag includes calcium sulfate, and the molar ratio of the fixed carbon to calcium sulfate in the sulfiding conditioning agent is 2-5:1; the sulfur content in the sulfiding conditioning agent is 1-3 times the theoretical sulfur content required to sulfidize all the metal oxides in the hot copper slag into metal sulfides.

[0006] In summary, both of the above methods disclose a method for comprehensively recovering valuable metals in copper slag using a slow cooling-flotation process. However, the depletion agents used in the above two methods are a mixture of a sulfate phase and a carbonaceous reducing agent. In the actual reaction process, the carbonaceous reducing agent is required to first convert the sulfate and then sulfide the oxides in the hot copper slag, and additional flue gas will be generated during the process.

[0007] In view of this, there is an urgent need to develop a method for recycling and treating copper slag to solve the problems of additional flue gas generation and insufficient reduction effect in the existing copper slag recycling and treatment process. Summary of the Invention

[0008] The main purpose of the present invention is to provide a method for the coordinated depletion treatment of arsenic sulfide slag and copper slag and its application, so as to solve the problems of additional flue gas generation and insufficient reduction effect in the existing copper slag recovery process.

[0009] In the prior art, arsenic sulfide slag mainly comes from the process of disposing of high-concentration arsenic-containing waste acid and arsenic-containing electrolyte. These arsenic sulfide slags are rich in arsenic and sulfur. If these waste slags are directly stored or simply treated, it will not only cause a waste of valuable metal resources, but also cause serious pollution to the environment due to the release of harmful elements such as arsenic. At the same time, the existing copper slag recovery and treatment process has the problem of extra flue gas generation and insufficient reduction effect. In response to the above problems, the present invention directly carries out a sulfurization reaction between copper slag and arsenic sulfide slag, and slowly cools the hot slag after the reaction, making full use of the physical and chemical characteristics of the two materials. The obtained slowly cooled slag has a clearly defined metal matte phase and slag phase, so that the valuable metals such as copper, lead, and zinc in the copper slag are enriched and fixed in the metal matte phase after combining with the sulfur element, and the arsenic element in the arsenic sulfide slag is fixed in the slag phase, and no harmful smoke is generated, which solves the problems of large amount of harmful smoke, poor reduction effect, and low sulfurization enrichment rate in the prior art. Based on this idea, the inventor provides the solution of the present invention.

[0010] To achieve the above object, the present invention provides a method for the coordinated depletion of arsenic sulfide slag and copper slag, comprising the following steps:

[0011] Performing a sulfidation reaction between arsenic sulfide slag and copper slag to obtain hot slag, and slowly cooling the hot slag to obtain slowly cooled slag;

[0012] The slowly cooled slag comprises a metal matte phase and a slag phase with clear boundaries, in which not less than 96% of metal sulfides are enriched to form particles larger than 40 μm, and the arsenic element in the arsenic sulfide slag is fixed in the slag phase;

[0013] The arsenic sulfide slag has a moisture content of ≯1.5% and an average particle size of ≮200 mesh;

[0014] The mass ratio of the copper slag to the arsenic sulfide slag is 100:3.5-5.5.

[0015] Furthermore, the chemical composition (wt%) of the arsenic sulfide slag includes: As35-55, S20-60, in terms of mass fraction.

[0016] Furthermore, the method further comprises: before subjecting the arsenic sulfide slag to a sulfidation reaction with the copper slag, drying and grinding the arsenic sulfide slag to obtain the arsenic sulfide slag with a moisture content of ≯1.5% and an average particle size of ≮200 meshes.

[0017] Furthermore, the chemical composition of the copper slag includes, by mass fraction (wt%): Fe 20-50, Cu 0.2-5.0, Pb 0.3-3.0, and Zn 1.0-5.0.

[0018] Preferably, the conditions of the sulfurization reaction include at least: a temperature of 1150-1350° C. and a time of 1-2 hours.

[0019] Furthermore, the slow cooling conditions at least include: a slow cooling rate of 1-10°C / min.

[0020] Furthermore, the method further comprises: the hot slag is slowly cooled to room temperature and then left to stand for treatment, and the time for the standing treatment is more than 24 hours.

[0021] Furthermore, the method further comprises: subjecting the slowly cooled slag to grinding treatment and flotation treatment in sequence, and further separating and recovering metal sulfides, alloys and depleted slag.

[0022] Furthermore, the grinding treatment conditions are controlled so that the average particle size of the slowly cooled slag is 100-200 meshes.

[0023] The present invention also provides an application of the method for co-depleting arsenic sulfide slag and copper slag in the recovery of valuable metals in copper slag obtained by pyrometallurgical copper smelting.

[0024] The beneficial effects of the present invention are as follows:

[0025] The treatment method provided by the present invention directly uses arsenic sulfide slag, which is also a solid waste, as a copper slag depletion agent without the need for additional reducing agents. Through the depletion-slow cooling process, the metal matte phase and the slag phase in the obtained slow cooling slag are clearly demarcated, and more than 96% of valuable metal sulfides such as copper, lead, and zinc are enriched to form particles larger than 40 μm, which is very convenient for subsequent flotation process and realizes comprehensive recovery of copper slag resources.

[0026] The treatment method provided by the present invention can also simultaneously treat arsenic sulfide slag, fix the arsenic element and other impurity elements therein in the slag phase, and no harmful smoke and dust is generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0028] Figure 1 This is the SEM image of the slowly cooled slag of Example 1 provided by the present invention.

[0029] Figure 2 This is a surface scanning analysis diagram of each element in the slowly cooled slag of Example 1 provided by the present invention.

[0030] Figure 3This is the SEM image of the slowly cooled slag of Example 3 provided by the present invention.

[0031] Figure 4 This is a surface scanning analysis diagram of each element in the slowly cooled slag of Example 3 provided by the present invention.

[0032] The realization of the objectives, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] Moreover, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] When numerical ranges are given in the examples, it should be understood that unless otherwise specified herein, both endpoints of each numerical range and any value between the two endpoints may be used. Unless otherwise defined, all technical and scientific terms used herein are consistent with the prior art as understood by those skilled in the art and the description of the present invention. Any prior art methods, devices, and materials similar or equivalent to those described in the examples of the present invention may also be used to implement the present invention.

[0036] The room temperature or normal temperature mentioned in the present invention refers to 25±5°C.

[0037] As mentioned above, the present invention provides a method for the coordinated depletion of arsenic sulfide slag and copper slag, comprising the following steps:

[0038] Performing a sulfidation reaction between arsenic sulfide slag and copper slag to obtain hot slag, and slowly cooling the hot slag to obtain slowly cooled slag;

[0039] The slowly cooled slag comprises a metal matte phase and a slag phase with clear boundaries, in which not less than 96% of metal sulfides are enriched to form particles larger than 40 μm, and the arsenic element in the arsenic sulfide slag is fixed in the slag phase;

[0040] The arsenic sulfide slag has a moisture content of ≯1.5% and an average particle size of ≮200 mesh;

[0041] The mass ratio of the copper slag to the arsenic sulfide slag is 100:3.5-5.5.

[0042] The method of the present invention synergistically depletes copper slag and arsenic sulfide slag in a specific ratio, combines the valuable metals in the copper slag with the sulfur element in the arsenic sulfide and fixes them in the metal matte phase, and then enriches the valuable metal sulfides through a slow cooling process, thereby obtaining a slow-cooling slag with a clear boundary between the metal matte phase and the slag phase. More than 96% of the valuable metal sulfides such as copper, lead, and zinc are enriched to form particles larger than 40 μm, making subsequent flotation treatment easier and separating the valuable metals from impurities more thorough.

[0043] The treatment method provided by the present invention has a clean and efficient overall process, can achieve the goal of waste-free production, is in line with the national strategic orientation of "treating waste with waste", and is expected to promote the smelting industry to move towards the goal of "zero waste".

[0044] The method provided by the present invention is mainly aimed at arsenic sulfide slag produced in the process of disposing of high-concentration arsenic-containing waste acid and arsenic-containing electrolyte. The arsenic grade in these arsenic sulfide slag materials is more than 35wt%. In some embodiments, the chemical composition (wt%) of the arsenic sulfide slag includes, in terms of mass fraction: As 35-55, S20-60. The long-term storage and disposal of such arsenic sulfide slag materials is likely to cause secondary pollution to the environment. On the one hand, it limits the sulfidation treatment process of acidic wastewater from metallurgical enterprises, and on the other hand, it also poses huge safety hazards. The present invention creatively uses arsenic sulfide slag solid waste as a copper slag depletion agent and synergistically treats it with copper slag. On the one hand, it can achieve efficient sulfidation enrichment of valuable metals in copper slag, and on the other hand, it can also achieve efficient reuse of solid waste resources, achieving the purpose of "treating waste with waste".

[0045] In some embodiments, the method further includes: before subjecting the arsenic sulfide slag to a sulfide reaction with the copper slag, drying and grinding the arsenic sulfide slag to obtain the arsenic sulfide slag with a moisture content of ≯1.5% and an average particle size of ≮200 mesh.

[0046] The present invention has no particular restrictions on the process conditions of the drying treatment and the grinding treatment. It only needs to be able to meet the aforementioned moisture content and average particle size requirements. Process conditions known in the art can be adopted. For example, the conditions of the drying treatment of the present invention include at least: a temperature of 80-100°C and a time of 24-36h.

[0047] The moisture content of the arsenic sulfide slag I can be, for example, 0.5%, 0.8%, 1%, 1.2%, 1.5% or any value between 0.5-1.5%. If the moisture content is too high, it may cause temperature fluctuations in the smelting furnace, affect the reaction stability, and even cause splashing or explosion risks. At the same time, the evaporation of water may carry volatile arsenic (such as As2O3) into the flue gas, increasing the difficulty of flue gas treatment and environmental risks.

[0048] The average particle size of the arsenic sulfide slag I is 200 mesh, 210 mesh, 220 mesh, 230 mesh, 240 mesh, 250 mesh, 260 mesh, 270 mesh, 280 mesh, 290 mesh, 300 mesh, or any value between 200 and 300 mesh. If the average particle size is too large, the mixing with the copper slag is uneven, the reaction contact area is small, and the reaction is insufficient. However, the incompletely reacted arsenic sulfide slag may hinder the uniform crystallization of the copper slag, resulting in an increase in the residual copper content in the depleted slag and a reduction in the metal recovery rate.

[0049] The inventors of the present invention have discovered that pre-treating the arsenic sulfide slag before mixing and controlling its moisture content and average particle size within an appropriate range can make the contact and mixing of the arsenic sulfide slag and copper slag in the electric furnace more uniform, and can effectively improve the binding efficiency and capacity of valuable metals and sulfur elements.

[0050] During the copper smelting process, a large amount of copper slag is produced. Copper slag is a product of matte smelting and matte converting during pyrometallurgy. Based on the slag-producing equipment, it can be divided into reverberatory slag, converter slag, and flash smelting slag. Based on the different slag cooling methods, it can be divided into water-quenched slag, naturally cooled slag, and thermally cooled slag. Based on the production process, it can be divided into smelting slag and converting slag.

[0051] The copper slag material in the copper slag of the present invention includes one or more of copper smelting slag, copper converting slag, refining slag, depleted slag, copper sulfide ore smelting slag, matte converting slag, laterite ore reduction smelting slag, and copper oxide ore reduction smelting slag. In some preferred embodiments, the chemical composition (wt%) of the copper slag includes: Fe 20-50, Cu 0.2-5.0, Pb 0.3-3.0, and Zn 1.0-5.0.

[0052] For example, the copper slag is in a molten state and can be connected to the pyrometallurgical copper smelting process. The copper slag after pyrometallurgical copper smelting can be directly recycled and processed, achieving integrated processing of copper-containing ore and copper slag. In some embodiments, the arsenic sulfide slag is fed into the hot copper slag through the copper smelter's slag ladle charging port or the side charging port of the cooling chute to achieve a sulfidation reaction with the hot copper slag; the temperature of the hot copper slag is 1150-1350°C.

[0053] It should be noted that the method of the present invention can directly flow the arsenic sulfide slag into the hot copper slag with a temperature of 1150-1350°C through the slag ladle feeding port of the copper smelter or the side feeding port of the cooling chute, so that most of the arsenic sulfide slag is immersed in the hot copper slag to ensure sufficient contact between the two, so that the sulfidation reaction proceeds efficiently without the need for additional reaction containers. The process is simple and efficient.

[0054] In other embodiments, the arsenic sulfide slag and copper slag are placed in an electric furnace for a sulfurization reaction. It should be noted that the method of the present invention can also be used to treat non-hot copper slag. The arsenic sulfide slag and copper slag are placed in an electric furnace in a proportional manner, and the temperature of the electric furnace is set within the sulfurization reaction temperature range. For example, if the electric furnace is placed at a holding temperature of 1150-1350°C, the sulfurization reaction can also occur efficiently.

[0055] As can be seen, the method of the present invention is applicable to two different application scenarios, treating both hot and non-hot copper slag. It only needs to meet the sulfurization reaction conditions of the copper slag and arsenic sulfide slag. Exemplarily, the sulfurization reaction conditions include at least a temperature of 1150-1350°C and a reaction time of 1-2 hours.

[0056] The specific vulcanization reaction that occurs in the present invention includes:

[0057] The oxidized valuable metals (MeO) in copper smelting slag and As2S3 in arsenic sulfide slag will undergo the following sulfidation reaction, realizing the sulfidation separation of the difficult-to-recover oxidized valuable metals in the copper slag material:

[0058] 3[MeO]+As2S3=3[MeS]+As2O3

[0059] Iron oxides and silicates in copper smelting slag will also be reduced and sulfided to [FeS], which will further sulfidize the metal oxides in the slag:

[0060] (MeO) + [FeS] = [MeS] + (FeO)

[0061] Valuable metal oxides are converted into sulfides through the above reactions and enter the sulfonium phase to aggregate and grow.

[0062] In some embodiments, the slow cooling conditions include at least a slow cooling rate of 1-10°C / min.

[0063] In some embodiments, the method further comprises: slowly cooling the hot slag to room temperature and then allowing it to stand for a period of more than 24 hours, so that the matte phase in the copper slag is fully enriched.

[0064] It should be noted that the slow-cooling slag obtained using the method of the present invention is a general solid waste. After recovering metals such as copper, lead, zinc, and iron through flotation, it can be sold as a raw material for cement and building materials, meeting the green and clean development requirements of the metallurgical industry. In some embodiments, the method further includes subjecting the slow-cooling slag to sequential grinding and flotation to further separate and recover metal sulfides, alloys, and depleted slag.

[0065] Among them, flotation, as a commonly used mineral processing method, has the advantages of low cost, strong applicability, easy process control, and environmental friendliness compared to hydrometallurgy and pyrometallurgy, and therefore has received more widespread attention. Flotation has been proven to achieve excellent flotation indicators when treating most copper slags and has been applied industrially on a large scale. However, there are certain limitations on the sulfide particle size (required to be above 40 microns) and the ore size (required to be between 0.01mm and 0.25mm). When the growth of metal sulfides is insufficient, they are mainly distributed in fine particles and have a complex interpenetration relationship with gangue minerals, resulting in poor separation effect. When the ore size is too large, grinding treatment is required to meet the flotation requirements. Otherwise, the ore particles are prone to sinking in the flotation process and enriched in the flotation tailings, affecting the recovery rate of valuable metals.

[0066] The metal sulfides in the slowly cooled slag obtained in the present invention aggregate and grow, and are concentrated in sulfide particles with a particle size greater than 40 μm, thereby reaching the particle size requirement that is beneficial to subsequent flotation.

[0067] In some embodiments, the grinding process conditions are controlled so that the average particle size of the slowly cooled slag is 100-200 meshes.

[0068] It's also important to note that grinding, a common flotation process, crushes ore particles in copper slag to an appropriate size, fully separating useful minerals from gangue minerals, thus facilitating subsequent flotation operations. Grinding creates finer copper slag particles with a larger surface area, making them more suitable for flotation agent adsorption and foam transport, thereby improving flotation recovery and concentrate grade.

[0069] In some embodiments, the flotation process may include the steps of adding a flotation agent to allow the matte particles to sink to the bottom, thereby separating the matte from the slag phase, and achieving separation and recovery of the metal sulfide and slag phases.

[0070] Metal sulfides are separated from the silicate copper slag after slow cooling to form a single metal matte phase, which is then recovered through a flotation process to recover valuable metals such as lead, zinc, and copper. The recovered metal matte / alloy (sulfides and alloys such as copper, lead, zinc, and iron) is sent to the next step of blowing for further recovery. The flotation tailings of the copper slag are then washed again to recover zinc ferrite and magnetite.

[0071] The present invention utilizes hazardous waste arsenic sulfide slag as a copper slag depletion agent, which can sulfide and enrich the valuable metals in the copper slag. It can also simultaneously process the arsenic sulfide slag and fix the arsenic element in the slag phase without generating harmful smoke and dust. It can realize the efficient recycling of solid waste resources and achieve the purpose of "treating waste with waste".

[0072] The method provided by the present invention also has the characteristics of simple process flow, cleanliness and high efficiency, and meets the requirements of environmentally friendly production.

[0073] As mentioned above, the present invention also provides the application of the above-mentioned method for the coordinated depletion treatment of arsenic sulfide slag and copper slag in the recovery of valuable metals in copper slag obtained by pyrometallurgical copper smelting.

[0074] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, all raw materials and instruments used are commercially available.

[0075] It should be noted that the arsenic sulfide slags in the following examples all come from Shandong Hengbang Smelting Co., Ltd.; and the copper slags all come from Bayannur Feishang Copper Co., Ltd.

[0076] In the following examples, the main components and contents of the arsenic sulfide slag and copper slag used are shown in Table 1 and Table 2, respectively.

[0077] Table 1 Main chemical composition and content of arsenic sulfide slag used in the examples

[0078] Ingredient content As / wt% S / wt% Arsenic sulfide slag-1 56.04 37.51 Arsenic sulfide slag-2 55.76 36.80 Arsenic sulfide slag-3 54.98 36.23

[0079] Table 2 Main chemical composition and content of copper slag used in the examples

[0080] Ingredient content Fe / wt% Cu / wt% Pb / wt% Zn / wt% Hot copper slag-1 44.63 3.98 1.14 2.78 Hot copper slag-2 45.23 4.13 1.78 2.58 Copper slag-3 43.29 4.12 1.21 3.24 Copper slag-4 44.52 4.32 1.45 2.98 Copper slag-5 44.51 4.23 2.30 3.32

[0081] Example 1

[0082] This embodiment provides a method for collaborative depletion of arsenic sulfide slag and copper slag, which specifically includes the following steps:

[0083] (1) drying and grinding the arsenic sulfide slag-1 in sequence to obtain arsenic sulfide slag I-1 having a moisture content of 1.5% and an average particle size of 200 mesh;

[0084] (2) 4.5 g of arsenic sulfide slag I-1 was added to the hot copper slag-1 at a temperature of 1180° C. (the mass ratio of hot copper slag-1 to arsenic sulfide slag I-1 was 100:4.5) through the side feeding port of the cooling chute to cause a sulfidation reaction inside for 1.5 hours to obtain hot slag-1, and the hot slag-1 was slowly cooled to room temperature at 1° C. / min and then allowed to stand for 24 hours to obtain slowly cooled slag;

[0085] (3) The slowly cooled slag was ground to 150 mesh and then sent to the flotation process for separation and recovery of valuable metal sulfides. The final calculated recovery rates of copper were 95.32%, lead 92.89%, and zinc 93.21%.

[0086] Example 2

[0087] This embodiment provides a method for collaborative depletion of arsenic sulfide slag and copper slag, which specifically includes the following steps:

[0088] (1) drying and grinding the arsenic sulfide slag-2 in sequence to obtain arsenic sulfide slag I-2 having a moisture content of 1.0% and an average particle size of 250 mesh;

[0089] (2) 5 g of arsenic sulfide slag I-2 was added to the hot copper slag-2 at a temperature of 1250°C (the mass ratio of hot copper slag-2 to arsenic sulfide slag I-2 was 100:5) through the side feeding port of the cooling chute, and a sulfidation reaction occurred inside for 1.5 hours to obtain hot slag-2, and the hot slag-2 was slowly cooled to room temperature at 1°C / min, and then allowed to stand for 24 hours to obtain slowly cooled slag;

[0090] (3) The slowly cooled slag was ground to 200 mesh and then sent to the flotation process for separation and recovery of valuable metal sulfides. The final calculated recovery rates of copper were 95.76%, lead 93.32%, and zinc 94.01%.

[0091] Example 3

[0092] This embodiment provides a method for collaborative depletion of arsenic sulfide slag and copper slag, which specifically includes the following steps:

[0093] (1) drying and grinding the arsenic sulfide slag-1 in sequence to obtain arsenic sulfide slag I-1 having a moisture content of 1.5% and an average particle size of 200 mesh;

[0094] (2) 5 g of arsenic sulfide slag I-1 and 100 g of copper slag-3 (the mass ratio of copper slag-3 to arsenic sulfide slag I-1 is 100:5) are placed in a muffle furnace, and the temperature is raised to 1250°C. The mixture is subjected to a sulfidation reaction at this temperature for 1 hour to obtain hot slag-3. The hot slag-3 is then slowly cooled to room temperature at 2°C / min and allowed to stand for 24 hours to obtain slowly cooled slag.

[0095] (3) The slowly cooled slag was ground to 200 mesh and then sent to the flotation process for separation and recovery of valuable metal sulfides. The final calculated recovery rates of copper were 96.12%, lead 92.98%, and zinc 94.04%.

[0096] Example 4

[0097] This embodiment provides a method for collaborative depletion of arsenic sulfide slag and copper slag, which specifically includes the following steps:

[0098] (1) drying and grinding the arsenic sulfide slag-3 in sequence to obtain arsenic sulfide slag I-3 having a moisture content of 1.0% and an average particle size of 300 mesh;

[0099] (2) 5 g of arsenic sulfide slag I-3 and 100 g of copper slag-4 (the mass ratio of copper slag-4 to arsenic sulfide slag I-3 is 100:5) are placed in a muffle furnace, and the temperature is raised to 1250°C. The mixture is subjected to a sulfidation reaction at this temperature for 1 hour to obtain hot slag-4. The hot slag-4 is then slowly cooled to room temperature at 1°C / min and allowed to stand for 24 hours to obtain slowly cooled slag.

[0100] (3) The slowly cooled slag was ground to 200 mesh and then sent to the flotation process for separation and recovery of valuable metal sulfides. The final calculated recovery rates of copper were 96.78%, lead 93.56%, and zinc 94.47%.

[0101] Example 5

[0102] This embodiment provides a method for the coordinated depletion of arsenic sulfide slag and copper slag, which is carried out with reference to the method of Example 3, except that: in step (2), the temperature of the sulfidation reaction is 1150°C.

[0103] Example 6

[0104] This embodiment provides a method for the coordinated depletion of arsenic sulfide slag and copper slag, which is carried out with reference to the method of Example 1, except that: in step (2), the temperature of the sulfidation reaction is 1350°C.

[0105] Comparative Example 1

[0106] This comparative example provides a method for depleting copper slag, which is carried out with reference to the method of Example 1, except that no arsenic sulfide slag is added.

[0107] The specific steps include:

[0108] Copper slag-5 was directly cooled to room temperature at a slow cooling rate of 1°C / min and then allowed to stand for 24 hours to obtain slow cooling slag. The slow cooling slag was ground to 150 mesh and then sent to the flotation process for separation and recovery of valuable metal sulfides. The final calculated copper recovery rate was 88.02%, and lead and zinc were not enriched in the sulfides.

[0109] Comparative Example 2

[0110] This comparative example provides a method for the coordinated depletion of arsenic sulfide slag and copper slag, which is carried out with reference to the method of Example 1, except that: in step (1), the arsenic sulfide slag-1 is not dried or ground.

[0111] The slowly cooled slags of Examples 1-6 and Comparative Examples 1-2 were ground and then subjected to flotation. The enrichment rate of valuable metals in sulfides, copper recovery rate, lead recovery rate, and zinc recovery rate were calculated. The valuable metals include metal elements such as copper, lead, and zinc. The calculation results are shown in Table 3.

[0112] Table 3

[0113]

[0114] As can be seen from the above table, the present invention synergistically depletes copper slag and arsenic sulfide slag in a specific ratio, combines the valuable metals in the copper slag with the sulfur element in the arsenic sulfide and fixes them in the metal matte phase, and then enriches the valuable metal sulfides through a slow cooling process, thereby obtaining a slow-cooling slag with a clear boundary between the metal matte phase and the slag phase. In addition, more than 96% of the valuable metal sulfides, such as copper, lead, and zinc, are enriched to form particles larger than 40 μm, resulting in a high enrichment rate, which makes subsequent flotation treatment easier.

[0115] In Comparative Example 1 in which no arsenic sulfide slag was added, the sulfide enrichment rate was significantly reduced, and valuable metals such as lead and zinc could not be recovered.

[0116] Analysis example 1

[0117] The slow cooling slag obtained in Example 1 and Example 3 were subjected to SEM-EDS testing. The specific test results are shown in Figures 1-4 .

[0118] in, Figure 1 This is the SEM image of the slowly cooled slag of Example 1 provided by the present invention. Figure 2 This is a surface scanning analysis diagram of each element in the slowly cooled slag of Example 1 provided by the present invention. Figure 3 The SEM image of the slowly cooled slag of Example 3 provided by the present invention is as follows: Figure 4 This is a surface scanning analysis diagram of various elements in the slowly cooled slag of Example 3 provided by the present invention.

[0119] from Figure 1 and Figure 3 It can be seen that most of the metal sulfides can be enriched to form particles larger than 40μm, and the mineral phase boundaries between the metal matte phase and the slag phase are clear, which is very beneficial to the subsequent flotation process.

[0120] from Figure 2 and Figure 4 As can be seen from the figure, the distribution of Cu, S, Zn, and Pb is essentially uniform, indicating that they primarily form sulfides and enter the matte phase. The distribution of the remaining elements, such as Fe, Si, and Ca, is essentially uniform, indicating that these elements constitute the slag phase. Due to the relatively small amount of arsenic sulfide used, the As signal is relatively weak, but As is observed to be primarily distributed in the slag phase, indicating that As is fixed in the slag and no harmful smoke is generated. This is likely due to the As being fixed through coupling reactions with other substances in the slag phase.

[0121] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0122] The above technical solutions of the present invention are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for the coordinated depletion of arsenic sulfide slag and copper slag, characterized in that: The following steps are involved: Performing a sulfidation reaction between arsenic sulfide slag and copper slag to obtain hot slag, and slowly cooling the hot slag to obtain slowly cooled slag; The slowly cooled slag comprises a metal matte phase and a slag phase with clear boundaries, in which not less than 96% of metal sulfides are enriched to form particles larger than 40 μm, and the arsenic element in the arsenic sulfide slag is fixed in the slag phase; The arsenic sulfide slag has a moisture content of ≯1.5% and an average particle size of ≮200 mesh; The mass ratio of the copper slag to the arsenic sulfide slag is 100:3.5-5.

5.

2. The method for collaborative depletion of arsenic sulfide slag and copper slag according to claim 1, characterized in that: Calculated by mass fraction, the chemical composition (wt%) of the arsenic sulfide slag includes: As 35-55, S20-60.

3. The method for collaborative depletion of arsenic sulfide slag and copper slag according to claim 2, characterized in that: The method further comprises: before subjecting the arsenic sulfide slag to a sulfidation reaction with the copper slag, drying and grinding the arsenic sulfide slag to obtain the arsenic sulfide slag with a moisture content of ≯1.5% and an average particle size of ≮200 meshes.

4. The method for collaborative depletion of arsenic sulfide slag and copper slag according to claim 1, characterized in that: Calculated by mass fraction, the chemical composition (wt%) of the copper slag includes: Fe 20-50, Cu 0.2-5.0, Pb 0.3-3.0, and Zn 1.0-5.

0.

5. The method for collaborative depletion of arsenic sulfide slag and copper slag according to claim 1, characterized in that: The conditions of the sulfurization reaction include at least: a temperature of 1150-1350° C. and a time of 1-2 hours.

6. The method for collaborative depletion of arsenic sulfide slag and copper slag according to claim 1, characterized in that: The slow cooling conditions at least include: a slow cooling rate of 1-10°C / min.

7. The method for collaborative depletion of arsenic sulfide slag and copper slag according to claim 6, characterized in that: The method further comprises: slowly cooling the hot slag to room temperature and then allowing it to stand for treatment, and the time for the standing treatment is more than 24 hours.

8. The method for collaborative depletion of arsenic sulfide slag and copper slag according to claim 1, characterized in that: The method further comprises: subjecting the slowly cooled slag to grinding and flotation treatments in sequence, and further separating and recovering metal sulfides, alloys and depleted slag.

9. The method for collaborative depletion of arsenic sulfide slag and copper slag according to claim 8, characterized in that: The grinding process conditions are controlled so that the average particle size of the slowly cooled slag is 100-200 meshes.

10. Use of the method for synergistic depletion of arsenic sulfide slag and copper slag according to any one of claims 1 to 9 in the recovery of valuable metals from copper slag obtained from pyrometallurgical copper smelting.

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