CN111979423A - Method for reinforced recovery of valuable metals in copper smelting slag by using gypsum slag - Google Patents

Abstract

The invention discloses a method for strengthening and recovering valuable metals in copper smelting slag by using gypsum slag, which comprises the following steps: (1) uniformly mixing gypsum residues and a carbonaceous reducing agent, and granulating or tabletting to obtain mixed granules or mixed tablets; (2) adding the obtained mixed granules or mixed flakes into the high-temperature copper smelting slag; (3) and (3) slowly cooling the mixture obtained in the step (2) to obtain slowly-cooled slag. Compared with the prior art, the method has the advantages of low energy consumption, high metal recovery rate, low cost, simple flow, simple materials, easy realization of industrial application and very high industrial application prospect and value.

Description

A method for strengthening the recovery of valuable metals in copper smelting slag by utilizing gypsum slag

technical field

The invention belongs to the technical fields of metallurgical engineering, chemical engineering and industrial solid waste resource utilization, and relates to a method for using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag.

Background technique

Pyrochemical copper smelting generally includes matte smelting, matte blowing, anode refining and anode pouring to produce anode plates for electrolytic refining. The process will produce smelting slag equivalent to 3 to 4 times the mass of metallic copper, which is mainly composed of oxide components such as Fe _x O, SiO ₂ , CaO, MgO, ZnO, Al ₂ O ₃ , and also contains a small amount of Cu, Ni, Ag Equivalent valuable metals and a certain amount of harmful elements such as As and Pb. Blowing slag and pyro-refining slag generally contain high copper content, but their volume is small, so they can be used for return treatment.

Smelting slag is the largest smelting slag in copper smelting plants, and it is also the main way to open the material. The main phases of copper smelting slag are fayalite (2FeO·SiO ₂ ), magnetic iron oxide (Fe ₃ O ₄ ) and oxides Molten glass body, the main chemical elements include Fe, O, Si, Ca, Zn, Al, Mg, Pb, S, As, etc. In addition, it also contains a certain amount of Cu, Au, Ag, S, and in special cases Ni, Co, etc. Valuable metals, recovering relevant valuable metals from slag can not only improve resource utilization, but also reduce the adverse impact of smelting slag on the ecological environment. Copper smelting slag generally contains 1-6wt% Cu, and also contains valuable metals such as Ag, which need to be further recovered. At present, there are two common processes to recover valuable metals such as copper. Slag slow cooling and grinding flotation is the process with high metal recovery rate. The flotation slag concentrate is returned to the smelting system, and the beneficiation tailings generally contain about 0.3 copper wt%, it is sold as a by-product to make cement. Valuable metals can also be recovered by the electric furnace depletion and smelting slag process. The obtained electric furnace final slag contains about 0.5wt% of copper. As a rust agent, most copper enterprises in my country use the slag slow cooling-grinding flotation process.

In the current production practice of various oxygen-enriched smelting technologies, the reaction temperature in the smelting stage is generally controlled to be 1180 to 1320 °C, the oxygen potential of the control system is 10 ^-8 to 10 ^-9 atm, and the mass ratio of Fe/SiO ₂ in the slag is 1.00 to 1.00 to 1.90, the Fe ₃ O ₄ content in the slag is 5-32 wt %, and the copper content in the slag is 1-6 wt %.

In the treatment of smelting slag, valuable metals such as Au and Ag migrate with Cu, and the phase morphology and reaction law of copper in the slag should be considered. After the smelting slag is diluted by electric furnace, clarified and separated, the copper content of the slag is about 0.5-0.8wt%; after slow cooling, grinding and flotation, the copper content of the tailings is about 0.3wt%. It can be seen from the comparison that the technical route of slow cooling-milling flotation in the two industrialized technical routes can obtain higher copper (valuable metal) recovery rate, but there are still technical limitations, and the copper content of tailings is close to that of oxidized copper ore mining. border grade. With the increasing scarcity of resources, it is of great significance to further strengthen the recovery of metals such as Cu in smelting slag.

The occurrence form of copper in smelting slag has an important influence on the selection and recovery effect of copper recovery process. The process mineralogical study of slow cooling slag shows that copper exists in three forms in smelting slag, which are sulfide forms, including Cu ₂ S, CuFeS ₂ , etc., followed by oxide forms, including CuO, Cu ₂ O, Cu ₂ O·Fe ₂ O ₃ , etc., and finally a small amount of metallic copper dispersed particles. Production practice and scientific research show that the production of high-grade matte will lead to high Fe ₃ O ₄ content in slag, increase in slag viscosity, poor separation conditions between matte and slag, and increase in slag copper content.

CN101491789A discloses a beneficiation process for mixing three copper smelting processes of flash furnace, converter and depletion electric furnace. The beneficiation method is used to recover copper in the mixed slag, but it is found that the recovery of valuable metals in oxidized state is difficult and the comprehensive recovery rate of metals is low.

Electric furnace depletion is a widely used method to strengthen the recovery of smelting slag copper. The high-temperature smelting slag is added to the depletion electric furnace through a chute alone or together with copper matte. Slag discharge, the slag is quenched by water and sold out, and the copper matte is accumulated to a certain amount and discharged from the matte mouth. In the depletion electric furnace, the collection of small particles of matte is mainly completed, and an appropriate amount of reducing agent is added. However, the cost of this process scheme is high, and more copper is lost with the electric furnace slag. CN104404259A is an improvement on the depletion process of ordinary electric furnaces, and discloses a method for co-processing of copper-nickel-cobalt smelting slag and gypsum slag to recover valuable metals. The reducing agent, gypsum slag and flux are injected into the depletion through the carrier _N2 The electric furnace, after standing in a constant temperature range, recovers valuable metals from the matte phase, and depletes the slag by water quenching as a cement raw material. This method improves the sulfur content of the slag through gypsum, which is conducive to the transformation of copper in the slag into matte, but This method has the disadvantages of high energy consumption, high residual Cu content in slag, lower comprehensive metal recovery rate than slow cooling-flotation process, complex materials, long preparation process, need to rely on a depletion electric furnace, and limited application.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, and to provide a gypsum slag for enhanced recovery of copper smelting slag with low energy consumption, high metal recovery rate, low cost, simple process, simple material and easy industrial application. Valuable metal method.

In order to solve the above technical problems, the present invention adopts the following technical solutions.

A method for utilizing gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, comprising the following steps:

(1) Mix the gypsum slag and the carbonaceous reducing agent uniformly, and perform granulation or tableting to obtain mixed granules or mixed tablets;

(2) adding the obtained mixed pellets or mixed flakes into the high-temperature copper smelting slag;

(3) Slowly cooling the mixture obtained in step (2) to obtain slow cooling slag.

In the above-mentioned method of using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, in the step (3), the slow cooling rate is 1-10°C/min.

In the above-mentioned method for using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, in the step (1), the mass ratio of gypsum slag to carbonaceous reducing agent is 1:1 to 5:1.

In the above-mentioned method for using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, the quality of gypsum in the mixed pellets or mixed flakes is 2-6 times the copper content in the high-temperature copper smelting slag.

In the above-mentioned method for using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, the temperature of the high-temperature copper smelting slag is 1180-1320°C.

In the above-mentioned method for using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, the gypsum slag is the gypsum waste slag produced by the sewage acid treatment system of the copper smelter, or the desulfurized gypsum produced by the treatment of tail gas and ring-collected flue gas. scum.

In the above-mentioned method for using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, the carbonaceous reducing agent is one or more of pulverized coal, carbon powder, and petroleum coke.

The above-mentioned method for using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, the copper smelting slag is flash smelting slag, oxygen-rich bottom blowing smelting slag, Osmet top blowing smelting slag, Vanuco One or more of side-blown smelting slag and silver furnace smelting slag.

In the above-mentioned method of using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, the granulation or tableting method is agglomeration granulation, extrusion granulation or mechanical tableting.

In the above-mentioned method for using gypsum slag to strengthen the recovery of valuable metals in copper smelting slag, preferably, the steps (2) and (3) are performed in a slag bag.

Compared with the prior art, the advantages of the present invention are:

1. The existing recovery and treatment process of valuable metals in copper smelting slag usually has shortcomings such as high residual Cu content in tailings, high energy consumption, and low Cu recovery rate. The inventor's research found that in the process of processing copper smelting slag, due to the dispersion of fine mineral particles and the chemical dissolution of copper oxides, the recovery rate of slow cooling-flotation and electric furnace depletion in the existing process is limited. limit. After a lot of research, the inventor innovatively proposed an enhanced recovery process for valuable metals in copper smelting smelting slag. By granulating gypsum slag and carbonaceous reducing agent, and then directly adding it to high-temperature copper slag, the slag is slowly cooled in the process. Completion of gypsum reduction and smelting slag ore phase recombination, the slow cooling process is conducive to the precipitation of dissolved copper oxide, the CaS formed by reduction induces copper ore phase reorganization, and increases the particle size and proportion of sulfide copper and metallic copper. Controlled cooling The speed slowly cools the system to room temperature. During the slow cooling process, the heat of the slag itself completes the reduction and decomposition of the gypsum, and the generated CaS migrates to the main body of the slag. The slow-cooling slag with high separation and high selectivity has the advantages of simple and easy process, low energy consumption and high recovery rate of valuable metals.

2. The present invention can complete the recovery of valuable metals by directly utilizing the heat of high-temperature smelting copper slag, without additional heating, greatly reducing energy consumption, and requiring no specific equipment, the process is simple, and the process is simple. With the invented process, the obtained slag is easily broken, easy to dissociate, and has a high degree of selectivity. After simple subsequent beneficiation, the Cu content in the tailings is lower than that of the existing various types of copper smelting slag treatment and recovery processes. The content of Cu in the medium increases the recovery rate of valuable metals and Cu.

3. The process of the present invention completes the relevant reactions in the slow cooling stage of the slag, strengthens the recovery process of valuable metals, and can be directly applied to production.

4. The process of the present invention further controls the cooling rate of the system to be 1 to 10 °C/min, so that the sulfide particles are continuously formed and slowly grown, which is beneficial to reduce the residual rate of Cu in the tailings. The residual rate is as low as 0.2wt.% or less, even as low as 0.15wt.%, which can effectively improve the recovery rate of Cu, and the slow-cooling slag obtained is easily broken, easy to dissociate, and has a high degree of selectivity, which is convenient for subsequent beneficiation. .

5. The process of the present invention is conducive to fully reducing gypsum by further controlling the addition ratio of gypsum slag to reducing agent and slag, and completes the phase reorganization of copper when the vulcanizing agent CaS is sufficient.

6. Copper is fine grained in the slag, and even microscopic and sub-microscopic can be found in the gaps or lattices of other minerals. Therefore, the slag must be ground to dissociate the copper mineral monomer. Generally speaking, copper mineral particles with a particle size above 45µm can be effectively and economically dissociated, while too small particles are not easy to dissociate and are not economical. The slow-cooling slag obtained by the process of the invention includes Fe-O-Si-Ca slag phase and sulfide phase with a size greater than 50 μm. There is a clear boundary between the two, which is conducive to the dissociation of mineral monomers and the formation of Cu and other valuable metals in the sulfide phase. Efficient recovery in flotation.

Description of drawings

Figure 1 is a sample picture of the slow cooling slag obtained in Example 1.

2 is a XRD comparison diagram of the slow cooling of the original slag and the slow cooling slag obtained in Example 1.

FIG. 3 is a graph showing the results of SEM inspection of the slow-cooling slag obtained in Example 1. FIG.

4 is a sample picture of the slow-cooling slag obtained in Example 2.

5 is a XRD comparison diagram of the slow cooling of the original slag and the slow cooling slag obtained in Example 2.

FIG. 6 is a graph showing the SEM inspection results of the slow-cooling slag obtained in Example 2. FIG.

FIG. 7 is a sample picture of the slow cooling slag obtained in Example 3. FIG.

8 is a XRD comparison diagram of the slow cooling of the original slag and the slow cooling slag obtained in Example 3.

FIG. 9 is a graph showing the results of SEM inspection of the slow-cooling slag obtained in Example 3. FIG.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

In the present invention, the gypsum slag is mixed with the carbonaceous reducing agent in proportion, and the pellets (granulation or tableting) are formed and dried for use. The mixed pellets are added to the high-temperature smelting slag, and the gypsum is reduced and decomposed by the heat of the slag itself, and the generated CaS migrates to the main body of the slag, so that the phase morphology of valuable metals such as copper in the slag changes, and the cooling rate is controlled to slowly cool the system to At room temperature, slow-cooling slag that is easily broken, easy to dissociate, and highly selectable is formed.

A method of utilizing gypsum slag to strengthen the recovery of valuable metals in copper smelting slag of the present invention comprises the following steps:

(1) Mix the gypsum slag and the carbonaceous reducing agent uniformly in proportion, and granulate (pellet/tablet) to obtain mixed granules;

(2) adding the obtained mixed pellets to the high-temperature copper smelting slag (high-temperature copper smelting slag);

(3) Slowly cooling the mixture obtained in step (2) to obtain slow cooling slag.

In the step (3), the cooling rate is 1-10°C/min.

In the step (1), the ratio of the gypsum slag and the solid carbonaceous reducing agent is calculated according to the chemical reaction, and the mass ratio of the gypsum slag and the carbonaceous reducing agent is 1:1-5:1.

In step (2), the added amount of the mixed pellets is measured according to the copper content of the slag, and the added amount of gypsum in the control pellets is 2 to 6 times, preferably 2 to 5 times, of the copper content of the slag.

The temperature of the high-temperature copper melting slag is the slag discharge temperature in industrial production, usually 1180-1320°C.

The gypsum slag is the gypsum waste slag produced by the sewage acid treatment system of the copper smelter, or the desulfurized gypsum slag produced by the treatment of tail gas and ring-collecting flue gas.

The carbonaceous reducing agent is one or more of pulverized coal, carbon powder and petroleum coke.

The copper smelting slag is one or more of flash smelting slag, oxygen-rich bottom blowing smelting slag, Osmet top blowing smelting slag, Vanyukov side blowing smelting slag, and silver furnace smelting slag.

The method of granulation or tableting in step (1) is agglomeration granulation, extrusion granulation or mechanical tableting.

The slow cooling operation can be carried out in various atmospheres, for example, can be carried out in an air atmosphere or an inert gas atmosphere, and the steps (2) and (3) in the process are preferably carried out in a slag bag.

The raw materials used in the embodiments of the present invention are as follows. It should be noted that the raw materials of copper smelting slag, gypsum slag and reducing agent used in the present invention are not limited to the following raw materials.

Copper smelting slag:

A domestic flash copper smelting plant produces matte with a grade of 65%, and its smelting slag chemical composition (wt%) is: Fe 39.86, SiO ₂ 31.26, CaO 3.27, Al ₂ O ₃ 2.31, Cu 1.41, Ni 0.01, Co 0.01 , (Ag+Au) 3.15g/t, recorded as smelting slag A; a domestic oxygen-rich bottom-blowing copper smelting plant produces matte with a grade of 69%, and the chemical composition (wt%) of the smelting slag is Fe 46.56, SiO ₂ 27.56 , CaO 1.27, Al ₂ O ₃ 2.61, Cu 3.25, Ni 0.02, Co 0.01, (Ag+Au) 5.29 g/t, and recorded as smelting slag B.

Gypsum slag:

The chemical composition (wt%) of gypsum slag treated by sewage in a domestic copper smelter is: Ca 29.52, S 7.94, As 8.56, F4.45, C 2.13, Zn 1.01, Cu 0.23, which is recorded as gypsum slag A; The copper smelter uses the limestone-gypsum method to treat the acid-making tail gas to form gypsum slag, and its chemical composition (wt%) is: Ca 22.52, S 15.53, Mg 1.51, Si 0.34, Al 0.01, Fe 0.01, which is recorded as gypsum slag B.

reducing agent:

The pulverized coal in the carbonaceous fuel is provided by the reagent supplier, and its chemical composition (wt%) is: C 79.16, H 5.11, S 2.85, N1.32, denoted as reducing agent A; the carbon powder in the carbonaceous fuel is provided by the reagent supplier, Its chemical composition (wt%) is: C 87.37, H 3.71, S 1.47, N 0.13, which is denoted as reducing agent B.

Example 1

A method of utilizing gypsum slag to strengthen the recovery of valuable metals in copper smelting slag of the present invention comprises the following steps:

(1) Mix and granulate gypsum slag A and reducing agent B in a mass ratio of 5:1, control the particle size of about 1mm, and dry the pellets for use.

(2) Add 2g of pellets to 20g of smelting slag A with a temperature of 1250°C under N ₂ atmosphere, and then control the cooling rate to be 4°C/min and slowly cool to room temperature to obtain slow-cooling slag.

Since this example is a laboratory operation, and the smelting slag A is the cooled slag taken from the factory, 20 g of the smelting slag A needs to be melted at 1250 ° C under _N2 atmosphere; in the actual treatment process, industrial copper The slag produced in the smelting process itself is high-temperature smelting slag. The environment does not need to use a protective atmosphere. Even if it is not carried out in a slag bag, it can be protected by an inert atmosphere. In order to reduce costs, it can also be carried out in an air atmosphere, because the molten slag is in a large volume and is in a molten state. The reaction between the gypsum slag and the reducing agent is a solid-liquid reaction. Only a small amount of samples on the surface will be oxidized, which will not have a substantial impact on the whole. Therefore, there is no special need for the atmosphere in industrial applications; while the laboratory case uses a large amount of samples. less, so a protective atmosphere is required.

In the actual industrial process, the slag in the copper smelting process is released from the furnace, and the slag is fed into the slag discharge during the cooling process in the slag ladle. The slag is slowly cooled using heat to complete the reduction and sulfidation process, and then strengthen the recovery of valuable metals. The above embodiment is a simulation. the above process.

The slow-cooling slag sample obtained in this example is shown in Figure 1. The slag is completely melted and deposited at the bottom of the cast iron crucible. The loose structure on the surface of the sample is formed by the escape of gases such as _CO2 generated by the reaction. The original slag directly slow-cooled sample and the slow-cooled slag obtained in Example 1 were subjected to XRD detection, and the obtained results were shown in Figure 2. The samples were subjected to metallographic preparation and analyzed by SEM, and the obtained results were shown in Figure 3.

As shown in the XRD test results of Fig. 2, in a nitrogen atmosphere, the main phases obtained after melting and slow cooling of smelting slag A are ferrous silicate and ferrous oxide; the slow cooling slag sample obtained by the process of this embodiment Among them, the diffraction peaks of phases such as CaSO or C _were not detected, indicating that the reduction reaction was carried out relatively thoroughly. In this embodiment, in the laboratory environment, the reduction and sulfidation reaction is an oxygen-free reaction, and an inert reaction such as nitrogen or argon is used. The atmosphere is acceptable, the reaction between gypsum and carbon is relatively complete, and the diffraction peak intensity of ferrous silicate in the sample decreases significantly, corresponding to the decomposition of the fayalite slag structure, and sulfides such as Cu ₅ FeS ₄ and Cu ₅ FeS ₆ and Fe alloys appear at the same time. The above-mentioned substances can be effectively recovered in the subsequent beneficiation stage.

The SEM picture in Figure 3 shows that the particle size of Cu-Fe-S matte particles and Fe-S sulfides are all larger than 100 μm, which can be efficiently recovered in sulfide flotation; at the same time, the above sulfides and Fe-O -Si-Ca slag phase has obvious boundaries, which is conducive to the dissociation of mineral monomers. And the EDS test was carried out on the points in Figure 3, and the obtained EDS test results showed that the chemical composition (wt%) of the Cu-Fe-S matte phase was: Cu 54.3, Fe 18.38, S 26.82, Si 0.12, Ca 0.01; Fe The chemical composition (wt%) of the -O-Si-Ca slag phase is: Fe 64.92, SiO ₂ 31.24, CaO 2.76, Al ₂ O ₃ 0.21, Cu 0.14.

Example 2

A method of utilizing gypsum slag to strengthen the recovery of valuable metals in copper smelting slag of the present invention comprises the following steps:

(1) Mix the gypsum slag B and the reducing agent A according to the mass ratio of 3:1 and make the tablet, and the tableting pressure is 2Mpa.

(2) Take 20g of smelting slag B and heat it up to 1200°C in a _N2 atmosphere, add 3g of gypsum tablet, slowly cool to room temperature, and control the cooling rate to 10°C/min to obtain slow-cooling slag.

The obtained sample is shown in Figure 4. The slag is completely melted and deposited on the bottom of the cast iron crucible. The loose structure on the surface of the sample is formed by the escape of gases such as _CO2 generated by the reaction. The original slag directly slow-cooled sample and the slow-cooled slag obtained in Example 2 were subjected to XRD detection, and the obtained results were shown in Figure 5. The samples were subjected to metallographic preparation and analyzed by SEM, and the obtained results were shown in Figure 6.

The XRD test results in Fig. 5 show that under nitrogen atmosphere, the main phases obtained after melting and slow cooling of smelting slag B are also ferrous silicate and ferrous oxide; the slow cooling slag obtained by the process of this embodiment In the sample, no diffraction peaks of CaSO ₄ or C were detected, indicating that the reduction reaction of gypsum was relatively complete, and the intensity of the diffraction peaks of ferrous silicate in the sample decreased significantly, corresponding to the decomposition of the fayalite slag structure, and Cu ₅ FeS ₄ appeared at the same time. , Cu ₅ FeS ₆ and other sulfides and the diffraction peaks of Fe alloys, the above substances can be effectively recovered in the beneficiation stage.

The SEM picture in Figure 6 shows that the particle size of Cu-Fe-S matte is greater than 100 μm, which is conducive to the efficient recovery of valuable metals such as Cu in sulfide flotation; at the same time, sulfide and Fe-O-Si-Ca There is a clear boundary in the slag phase, which is conducive to the dissociation of mineral monomers. And the EDS test was carried out on the points in Figure 6, and the obtained EDS test results showed that the chemical composition (wt%) of the Cu-Fe-S matte phase was: Cu 51.36, Fe 18.82, S 29.06, Si 0.08; Fe-O- The chemical composition (wt%) of the Si-Ca slag phase is: Fe 63.86, SiO ₂ 32.33, CaO 0.56, Cu 0.11.

Example 3

A method of utilizing gypsum slag to strengthen the recovery of valuable metals in copper smelting slag of the present invention comprises the following steps:

(1) The gypsum slag B and the reducing agent B are pelletized at a mass ratio of 1:1, and the diameter of the pellet is controlled to be 2 mm.

(2) Take 20g of smelting slag A and heat it up to 1250°C in a _N2 atmosphere, add 4g of pellets, slowly cool to room temperature, and control the cooling rate to 2°C/min to obtain slow-cooling slag.

The obtained sample is shown in Figure 7. The slag is completely melted and deposited on the bottom of the cast iron crucible. The loose structure on the surface of the sample is formed by the escape of gases such as _CO2 generated by the reaction. The original slag directly slow-cooled sample and the slow-cooled slag obtained in Example 3 were subjected to XRD detection, and the obtained results were shown in Figure 8. The samples were subjected to metallographic preparation and analyzed by SEM, and the obtained results were shown in Figure 9.

The XRD test results in Fig. 8 show that in the slow-cooling slag sample obtained by the process of this embodiment, no diffraction peaks of CaSO ₄ or C are detected, indicating that the gypsum is decomposed more thoroughly, and the intensity of the diffraction peaks of ferrous silicate in the sample decreases Obviously, corresponding to the decomposition of the fayalite slag structure, diffraction peaks of Cu ₅ FeS ₄ and other sulfides and Fe alloys appear at the same time, and these substances can be effectively recovered in the beneficiation stage.

The SEM picture in Figure 9 shows that the particle size of Cu-Fe-S matte is greater than 50 μm, which is conducive to the efficient recovery of valuable metals such as Cu in sulfide flotation; at the same time, sulfide and Fe-O-Si-Ca slag There is a clear boundary between the phases, which is conducive to the dissociation of mineral monomers. And the EDS test was carried out on the points in Figure 9, and the obtained EDS test results showed that the chemical composition (wt%) of the Cu-Fe-S matte phase was: Cu 57.51, Fe 15.33, S 26.55, Si 0.11; Fe-O- The chemical composition (wt%) of the Si-Ca slag phase is: Fe 66.12, SiO ₂ 30.75, CaO 2.56, Cu 0.09.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, without departing from the spirit and technical solutions of the present invention, can make many possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above, or modify them to be equivalent. Variant equivalent embodiments. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. A method for strengthening and recovering valuable metals in copper smelting slag by using gypsum slag is characterized by comprising the following steps:

(1) uniformly mixing gypsum residues and a carbonaceous reducing agent, and granulating or tabletting to obtain mixed granules or mixed tablets;

(2) adding the obtained mixed granules or mixed flakes into the high-temperature copper smelting slag;

(3) and (3) slowly cooling the mixture obtained in the step (2) to obtain slowly-cooled slag.

2. The method for enhanced recovery of valuable metals from copper smelting slag by using gypsum slag according to claim 1, wherein in the step (3), the slow cooling speed is 1-10 ℃/min.

3. The method for reinforced recovery of valuable metals in copper smelting slag by using gypsum slag as claimed in claim 1, wherein in the step (1), the mass ratio of gypsum slag to carbonaceous reducing agent is 1: 1-5: 1.

4. The method for reinforced recovery of valuable metals in copper smelting slag according to claim 1, wherein the mass of gypsum in the mixed granules or mixed tablets is 2-6 times of the copper content in the high-temperature copper smelting slag.

5. The method for enhanced recovery of valuable metals from copper smelting slag according to any one of claims 1 to 4, wherein the temperature of the high-temperature copper smelting slag is 1180 to 1320 ℃.

6. The method for reinforced recovery of valuable metals in copper smelting slag according to any one of claims 1 to 4, wherein the gypsum slag is gypsum slag generated by a waste acid treatment system of a copper smelting plant or desulfurized gypsum slag generated by treatment of tail gas and circular collected flue gas.

7. The method for reinforced recovery of valuable metals in copper smelting slag by using gypsum slag as claimed in any one of claims 1 to 4, wherein the carbonaceous reducing agent is one or more of pulverized coal, carbon powder and petroleum coke.

8. The method for reinforced recovery of valuable metals in copper smelting slag according to any one of claims 1 to 4, wherein the copper smelting slag is one or more of flash smelting slag, oxygen-enriched bottom blowing smelting slag, Osmant top blowing smelting slag, Vanecov side blowing smelting slag and silver furnace smelting slag.

9. The method for reinforced recovery of valuable metals in copper smelting slag by using gypsum slag as claimed in any one of claims 1 to 4, wherein the granulation or tabletting method is agglomeration granulation, extrusion granulation or mechanical tabletting.

10. The method for the enhanced recovery of valuable metals from copper smelting slag by using gypsum slag according to any one of claims 1 to 4, wherein the steps (2) and (3) are carried out in a slag ladle.

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