Method for Pretreating Lead-Zinc Sulfide Materials and Its Smelting Method

Abstract

The present invention provides a method for pretreating lead-zinc sulfide materials, comprising the steps of: S11, adding a slag-forming agent to the lead-zinc sulfide materials to obtain a mixed material; the lead element content in the lead-zinc sulfide materials is ≤20 wt%; the zinc element content is ≥25 wt%; wherein, the content of the basic slag in the mixed material is 25-35 wt%; S12, adding a fluxing agent to the mixed material to obtain a smelting material. By adding a slag-forming agent and a fluxing agent with a fixed ratio to the lead-zinc sulfide materials, this method reduces the melting point of the desulfurization product of the smelting raw material, i.e., the lead-zinc sulfide materials, enabling the desulfurization product of the lead-zinc sulfide materials to achieve complete melting. The present invention also provides a brand-new smelting method for lead-zinc sulfide materials (Zn≥25 wt%), solving problems such as the complex process flow of the prior art and the inability to smoothly achieve the flow between sections in bath smelting.

Description

Technical Field

[0001] The present invention relates to the fields of metallurgy and comprehensive utilization of urban mineral resources, and particularly to a method for pretreatment of lead-zinc sulfide materials and a smelting method thereof. Background Art

[0002] The bath smelting technology has significant advantages in terms of energy consumption, environmental protection, and recovery of valuable metals. The bath oxygen enrichment oxidation has a high desulfurization efficiency. Compared with the high SO2 soot pollution in the sintering process, its closed conditions can greatly reduce the environmental pollution load; the molten product after oxidation desulfurization directly flows into the reduction section for metal recovery, avoiding the process of reheating cold materials, and can greatly reduce the energy consumption in the smelting process. Therefore, currently, processes such as the "three-link furnace" lead smelting and QSL lead smelting in lead smelting all adopt the bath smelting method, achieving good production efficiency, lead recovery rate, and energy consumption cost control. For example, the QSL process uses oxygen bottom-blowing lead smelting. The furnace is divided into an oxidation smelting area and a slag reduction area by a partition wall; there are holes at the lower part of the partition wall for the melt to pass through. Granular concentrate is fed from the top of the oxidation area, oxygen is sprayed in by a lance at the bottom, and the melt undergoes desulfurization and smelting reactions. The generated lead liquid accumulates at the bottom here. The slag containing PbO passes through the slag dam and enters the reduction area to be reduced to lead by carbon and flows back to the bottom of the oxidation area. The lead liquid produced by smelting and the depleted slag are discharged from both ends of the furnace in a countercurrent state respectively, and the whole smelting process is carried out in a closed furnace.

[0003] However, currently, the bath lead-zinc smelting only targets the smelting of high-lead materials, and there are no reported engineering cases on the bath smelting of high-zinc materials (Zn content ≥ 25%). The main reason is that the product after oxidation desulfurization of high-zinc materials cannot flow smoothly between sections during the bath smelting process. Summary of the Invention

[0004] The main object of the present invention is to provide a method for pretreatment of lead-zinc sulfide materials, aiming to solve the problems that the existing technology does not target the smelting of lead-zinc sulfide materials with a relatively high zinc content, the process flow is complex, and it is impossible to smoothly achieve the flow between sections by using bath smelting.

[0005] To achieve the above object, the present invention provides a method for pretreatment of lead-zinc sulfide materials, including the steps:

[0006] S11, adding a slag-forming agent to the lead-zinc sulfide material to obtain a mixed material; the lead element content in the lead-zinc sulfide material ≤ 20wt%; the zinc element content ≥ 25wt%; wherein, the content of the basic slag in the mixed material is 25 - 35wt%; the basic slag is the total amount of CaO, SiO2, and FeO contained in the mixed material. x The total amount.

[0007] S12. Add a fluxing agent to the mixed material to obtain a smelting material; the fluxing agent includes one or more of copper-containing materials, manganese-containing materials, and lead-containing materials.

[0008] Further, in step S11, in the basic slag, the mass ratio of SiO2 to FeO x is 1.8 - 2.4; the mass ratio of CaO to SiO2 is 0.2 - 0.5.

[0009] Further, in step S11, the slag-forming agent includes one or more of industrial quartz sand, quicklime, and calcium carbonate.

[0010] Further, in step S12, the sources of the copper-containing material, the manganese-containing material, and the lead-containing material are one or more of smelting raw materials, industrial solid wastes, and urban minerals.

[0011] The present invention also provides a method for smelting lead-zinc sulfide materials, including the steps:

[0012] S21. Pretreat the lead-zinc sulfide material by using the method for pretreating lead-zinc sulfide materials as described above to obtain a smelting material.

[0013] S22. Perform oxidative desulfurization treatment on the smelting material to obtain a desulfurized product.

[0014] S23. Perform combined lead-zinc smelting on the mixed molten slag to obtain metallic lead and metallic zinc.

[0015] Further, in step S22, the process of oxidative desulfurization treatment includes blowing the smelting material; when the sulfur content in the smelting material < 1 wt%, terminate blowing.

[0016] Further, the blowing method includes top blowing, bottom blowing, or side blowing; the oxygen content during the blowing process > 20%.

[0017] Further, in step S22, the oxidative desulfurization process is carried out at 1150 - 1300 °C.

[0018] Further, in step S23, the combined lead-zinc smelting includes pyrometallurgical lead-zinc smelting and bath smelting; wherein, the pyrometallurgical lead-zinc smelting includes a sintering-sealed blast furnace smelting process.

[0019] Further, the bath smelting includes a triple furnace smelting process and a QSL smelting process.

[0020] The beneficial effects achieved by the present invention:

[0021] The method for pretreating lead-zinc sulfide materials provided by the present invention includes the steps: S11, adding a slag-forming agent to the lead-zinc sulfide materials to obtain a mixed material; the lead element content in the lead-zinc sulfide materials is ≤20 wt%; the zinc element content is ≥25 wt%; wherein, the content of the basic slag in the mixed material is 25-35 wt%; the basic slag is the total amount of CaO, SiO2 and FeO contained in the mixed material. x S12, adding a fluxing agent to the mixed material to obtain a smelting material; the fluxing agent includes one or several of copper-containing materials, manganese-containing materials and lead-containing materials. By adding a slag-forming agent and a fluxing agent with a fixed ratio to the lead-zinc sulfide materials, the melting point of the desulfurization product of the smelting raw material, i.e., the lead-zinc sulfide materials, is reduced, so that the desulfurization product of the lead-zinc sulfide materials can achieve full melting, and then smoothly flow between sections in the bath smelting process.

[0022] The present invention also provides a brand-new smelting method for lead-zinc sulfide materials (Zn≥25 wt%), which solves the problems of complex process flow in the prior art and the inability to smoothly achieve the flow between sections in bath smelting. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0024] Figure 1 It is a photograph of the melting result of the desulfurization product for Example 3;

[0025] Figure 2 It is a photograph of the flowing process of the desulfurization product for Example 4; wherein, from (a) to (f) is the continuous pouring-out process.

[0026] The realization of the object, functional features and advantages of the present invention will be further described with reference to the drawings in the embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0028] It should be noted that, without conflict, the following embodiments and the features in the embodiments may be combined with each other. It should also be understood that the terms used in the embodiments of the present invention are for describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used in the present invention, based on the understanding of those skilled in the art of the present technology field of the prior art and the description of the present invention, any methods, devices, and materials similar or equivalent to the methods, devices, and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0030] When an embodiment gives a numerical range, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. For the test methods without specific conditions noted in the following embodiments, they are generally carried out under conventional conditions or according to the conditions recommended by each manufacturer. The materials or reagents required in the following embodiments are commercially available unless otherwise specified.

[0031] To solve the problems of complex existing technical processes, serious pollution in zinc sintering refining, high energy consumption, etc., the present invention provides a method for recovering metallic zinc from high-zinc materials, including the steps:

[0032] S11, adding a slag-forming agent to the lead-zinc sulfide material to obtain a mixed material; the lead element content in the lead-zinc sulfide material ≤ 20 wt%; the zinc element content ≥ 25 wt%; wherein, the content of the basic slag in the mixed material is 25 - 35 wt%; the basic slag is the total amount of CaO, SiO2, and FeO contained in the mixed material. x of.

[0033] It should be noted that the lead-zinc sulfide material can specifically be sulfides, industrial lead-zinc sulfide concentrates, mixtures of high-copper zinc ores, lead concentrates, etc.

[0034] ZnS, PbS, and FeS2 in the lead-zinc sulfide material will form ZnO, PbO, and FeO through oxidative desulfurization. x , by adding a slag-forming agent, CaO and SiO2 are introduced into the mixed material to jointly form a five-component slag system ZnO - PbO - FeO x -CaO - SiO2. In the mixed material, the low-melting component PbO can first melt to form a melt and can form a PbO·xSiO2 phase. The high-melting component ZnO can undergo a phase transformation when the melting temperature reaches above 1100 °C to form phases such as ZnFe2O4, ZnSiO4, and Ca2ZnSi2O7, and these phases form a low-melting solid solution through eutectic action. By adjusting the above five-component slag system ZnO - PbO - FeO x- The distribution ratios of the components in CaO-SiO2 can achieve the synergistic mutual melting effect among the components, and a liquid slag can be jointly formed at a relatively low temperature, so the melting temperature of the desulfurization product (lead-zinc oxide material) can be effectively reduced.

[0035] S12. Add a flux to the mixed material to obtain a smelting material; the flux includes one or more of a copper-containing material, a manganese-containing material, and a lead-containing material.

[0036] Specifically, the addition of the copper-containing material, the manganese-containing material, and the lead-containing material can further form a six-component slag system ZnO-PbO-MO x -CaO-SiO2 on the basis of the formed five-component slag system ZnO-PbO-FeO x -FeO x -CaO-SiO2, where M is one or both of Cu and Mn. To further reduce the melting temperature of the overall slag system.

[0037] Exemplarily, when the added flux is a copper-containing material, Cu + undergoes ion exchange with Zn 2+ and penetrates into the lattice interior of the refractory phase ZnO, resulting in the instability and destruction of the ZnO crystal, thereby reducing the melting point of the overall smelting material, and this effect has not been found for other metal ions.

[0038] Exemplarily, when the added flux is a manganese-containing material, Mn 2+ can penetrate into the interior of the crystal structure of the refractory ZnFe2O4 and destroy it. Through the destruction of the crystal structure of the refractory phase, the melting of the high-zinc material is promoted.

[0039] Exemplarily, when the added flux is a lead-containing material, it can increase the proportion of PbO in the five-component slag system ZnO-PbO-FeO x -CaO-SiO2 and correspondingly reduce the proportion of ZnO in the slag system. Through thermodynamic analysis, it can be obtained that the melting temperature of the slag system decreases accordingly.

[0040] By adding a slag-forming agent and a flux with a fixed ratio to the lead-zinc sulfide material, the melting point of the desulfurization product of the smelting raw material, that is, the lead-zinc sulfide material, is reduced, so that the desulfurization product of the lead-zinc sulfide material can achieve complete melting, and then smoothly flow between the sections in the bath smelting process.

[0041] Furthermore, in step S11, in the basic slag, the mass ratio of SiO2 to FeO x is 1.8 to 2.4; the mass ratio of CaO to SiO2 is 0.2 to 0.5. When SiO2 and FeO xThe mass ratio is 1.8 to 2.4; when the mass ratio of CaO to SiO2 is 0.2 to 0.5, the synergistic melting effect between components can be achieved, and liquid slag can be formed together at a relatively low temperature.

[0042] Further, in step S11, the slag-forming agent includes one or more of industrial quartz sand, quicklime, and calcium carbonate.

[0043] Further, in step S12, the sources of the copper-containing material, manganese-containing material, and lead-containing material are one or more of smelting raw materials, industrial solid waste, and urban minerals.

[0044] Specifically, the copper-containing material can be industrial copper oxide, copper powder, scrap copper, copper concentrate, matte, copper-containing sludge, etc.; the manganese-containing material can be industrial manganese dioxide, manganese carbonate, manganese concentrate, etc., and the lead-containing material can be waste circuit boards and various connectors generated during the disassembly of waste circuit boards, waste lead plates, waste lead paste, lead-acid batteries, etc.

[0045] The present invention also provides a smelting method for lead-zinc sulfide materials, including the steps:

[0046] S21, pretreating the lead-zinc sulfide material by the method of pretreating lead-zinc sulfide materials as described above to obtain smelting materials.

[0047] S22, performing oxidative desulfurization treatment on the smelting materials to obtain desulfurized products.

[0048] S23, performing combined lead-zinc smelting on the mixed molten slag to obtain metallic lead and metallic zinc.

[0049] Further, in step S22, the process of oxidative desulfurization treatment includes blowing the smelting materials; when the sulfur content in the smelting materials < 1 wt%, the blowing is terminated.

[0050] Further, the blowing method includes top blowing, bottom blowing, or side blowing; the oxygen content during the blowing process > 20%.

[0051] Specifically, the iron element in the lead-zinc sulfide material mainly exists in the form of FeS2. The reason why Fe can maintain the divalent iron form is mainly that the following reaction prevents the formation of Fe2O3.

[0052] FeS2 + Fe2O3 + 2O2 → 3FeO + 2SO2

[0053] As the reaction proceeds further, the S in the materials is gradually removed, and FeO will be further oxidized to gradually form high-valent iron oxides such as Fe3O4 and Fe2O3.

[0054] Since FeO can combine with SiO2 to form the low-melting-point fayalite phase 2FeO·SiO2 (melting point 1178 °C), while Fe2O3 or Fe3O4 cannot combine with SiO2, and the melting points of Fe2O3 and Fe3O4 are as high as 1565 °C and 1595 °C respectively, resulting in a significant increase in the melting point of the slag. Therefore, by controlling the blowing process, that is, when the sulfur content in the smelting material is 1 wt%, the blowing is terminated to control the non-further oxidation of iron and ensure that iron mainly exists in the form of divalent FeO.

[0055] Further, in step S22, the oxidative desulfurization process is carried out at 1150 - 1300 °C.

[0056] Further, in step S23, the lead-zinc combined smelting includes pyrometallurgical lead-zinc smelting and bath smelting; among them, the pyrometallurgical lead-zinc smelting includes the sintering-sealed blast furnace smelting process. It should be noted that currently, the lead-zinc combined smelting mainly adopts the sintering-sealed blast furnace (ISP) method. After steps S21 and S22, the problems of heavy pollution load, large amount of returned powder, and low sulfur recovery efficiency in the sintering link of simply using the ISP technology can be effectively improved.

[0057] Further, the bath smelting includes the triple furnace smelting process and the QSL smelting process.

[0058] For a further understanding of the present invention, the following is an example for illustration:

[0059] Example 1

[0060] Smelting sulfides

[0061] 1. Measure the content of each component in the sulfide as 33.6 wt% ZnS, 31.5 wt% PbS, and 10.9 wt% FeS.

[0062] 2. Add quicklime and industrial quartz sand to the sulfide to obtain a mixed material. In the mixed material, CaO / SiO2 is 0.4, and SiO2 / Fe is 2.1.

[0063] 3. Then add 2.7 wt% Cu powder to form a smelting material with component contents of ZnS 33.6 wt%, PbO 31.5 wt%, Cu 2.7 wt%, FeS 10.9 wt%, CaO 6.0 wt%, and SiO2 15.3 wt% respectively.

[0064] 4. Carry out oxygen-enriched blowing on the smelting material at 1150 °C, with an oxygen-enriched concentration of 98% and an oxygen flow rate of 360 L·kg - 1 h -1 , and the SO2 content is measured by a flue gas analyzer and reduced to 20 mg / m3 When it is about [specific time], stop blowing and discharge the desulfurized product. It can be seen that the desulfurized product has good fluidity.

[0065] 5. The desulfurized product is measured by a nitrogen-sulfur analyzer, and its S content is 0.8 wt%. After melting point and high-temperature viscosity tests, the full melting temperature of this batching system is 1233 °C, and the high-temperature viscosity value is 0.165 Pa·S, meeting the requirements of subsequent lead-zinc combined smelting, and metallic lead and metallic zinc can be obtained.

[0066] Example 2

[0067] Smelt industrial lead-zinc sulfide concentrate

[0068] 1. The industrial lead-zinc sulfide concentrate contains 47.4 wt% zinc concentrate and 24.9 wt% lead concentrate.

[0069] 2. Add quicklime and quartz sand to the industrial lead-zinc sulfide concentrate to obtain a mixed material. In the mixed material, CaO / SiO2 is 0.4, and SiO2 / Fe is 2.1.

[0070] 3. Then add 11.6 wt% matte to form a smelting material with the following main component contents: Zn 24.7 wt%, Pb 12.4 wt%, S 22 wt%, Cu 8.2 wt%, Fe 6.2 wt%, CaO 6.7 wt%, and SiO2 14.8 wt%.

[0071] 4. Carry out oxygen-enriched blowing on the smelting material at 1250 °C, with an oxygen-enriched concentration of 90% and an oxygen flow rate of 400 L·kg - 1 h -1 , and when the SO2 content measured by the flue gas analyzer is reduced to about 20 mg / m 3 stop blowing and discharge the desulfurized product. It can be seen that the desulfurized product has good fluidity.

[0072] 5. The desulfurized product is measured by a nitrogen-sulfur analyzer, and its S content is 0.8 wt%. After melting point and high-temperature viscosity tests, the full melting temperature of this batching system is 1215 °C, and the high-temperature viscosity value is 0.145 Pa·S, meeting the requirements of subsequent lead-zinc combined smelting, and metallic lead and metallic zinc can be obtained.

[0073] Example 3

[0074] Smelt a mixture of high-copper zinc ore and lead concentrate

[0075] 1. Add quicklime and industrial quartz sand to the mixture of high-copper zinc ore and lead concentrate to obtain a mixed material. In the mixed material, CaO / SiO2 is 0.48, and SiO2 / Fe is 1.92.

[0076] 2. Then add lead matte, and the proportions of each component in the obtained smelting materials are 43.9 wt% of high copper-zinc ore, 26.3 wt% of lead concentrate, 6.9 wt% of lead matte, 13.4 wt% of quartz sand, and 9.5 wt% of quicklime.

[0077] 3. Carry out oxygen-enriched blowing on the smelting materials at 1250 °C, with an oxygen-enriched concentration of 95% and an oxygen flow rate of 250 L·kg - 1 h -1 , when the SO2 content measured by the flue gas analyzer is reduced to about 20 mg / m 3 , stop blowing, take samples and use a nitrogen-sulfur analyzer to measure the sulfur content to be 0.6 wt%, and discharge the desulfurized product.

[0078] 4. Measure that the main element contents in the desulfurized product are 28.22 wt% of Zn, 10.49 wt% of Pb, 8.98 wt% of Cu, 8.18 wt% of Fe, 7.60 wt% of Ca, 10.89 wt% of Si, and 0.02 wt% of S.

[0079] 5. Conduct a melting test on the desulfurized product at 1250 °C. It can be seen that the desulfurized product is completely melted, and the melt (desulfurized product) spreads along the bottom of the crucible. The melting result picture of the desulfurized product is as shown in Figure 1 . It is confirmed that it has good fluidity.

[0080] Example 4

[0081] Smelt the mixture of high copper-zinc ore and lead concentrate

[0082] 1. Add quicklime and industrial quartz sand to the mixture of high copper-zinc ore and lead concentrate to obtain a mixed material. In the mixed material, CaO / SiO2 is 0.2 and SiO2 / Fe is 2.4.

[0083] 2. Then add lead matte, and the proportions of each component in the obtained smelting materials are 43.9 wt% of high copper-zinc ore, 26.3 wt% of lead concentrate, 6.9 wt% of lead matte, 15.1 wt% of quartz sand, and 7.8 wt% of quicklime.

[0084] 3. Carry out oxygen-enriched blowing on the smelting materials at 1300 °C, with an oxygen-enriched concentration of 90% and an oxygen flow rate of 400 L·kg - 1 h -1 , when the SO2 content measured by the flue gas analyzer is reduced to about 20 mg / m 3 , stop blowing, take samples and use a nitrogen-sulfur analyzer to measure the sulfur content to be 0.7 wt%, and discharge the desulfurized product.

[0085] 4. The contents of the main elements in the desulfurization product are measured as follows: Zn 27.9 wt%, Pb 11.60 wt%, Cu 8.78 wt%, Fe 8.26 wt%, Ca 4.73 wt%, and S 0.7 wt%.

[0086] 5. The desulfurization product is subjected to a melting test at 1250°C. When the desulfurization product is discharged from the crucible, it can be seen that it flows out of the crucible quickly and has good fluidity. The pictures taken during the flowing process of the desulfurization product are as Figure 2 shown; among them, from (a) to (f) is the continuous pouring process. In summary, in the above technical solutions of the present invention, the above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the technical concept of the present invention, or direct / indirect application in other related technical fields are all included in the patent protection scope of the present invention.

Claims

1. A method for pretreating lead-zinc sulfide materials, characterized in that, Including the steps: S11. Adding a slag-forming agent to the lead-zinc sulfide material to obtain a mixed material; the lead element content in the lead-zinc sulfide material is ≤20 wt%; the zinc element content is ≥25 wt%. Among them, the content of the basic slag in the mixed material is 25-35 wt%; the basic slag is the total amount of CaO, SiO2 and FeO contained in the mixed material x ; in the basic slag, the mass ratio of SiO2 to FeO x is 1.8-2.4; the mass ratio of CaO to SiO2 is 0.2-0.5; S12. Adding a fluxing agent to the mixed material to obtain a smelting material; the fluxing agent includes one or more of a copper-containing material, a manganese-containing material, and a lead-containing material.

2. The method for pretreating lead-zinc sulfide materials according to claim 1, wherein In step S11, the slag-forming agent includes one or more of industrial quartz sand, quicklime, and calcium carbonate.

3. The method for pre-treating lead-zinc sulfide materials according to claim 1, wherein In step S12, the sources of the copper-containing material, the manganese-containing material, and the lead-containing material are one or more of smelting raw materials, industrial solid wastes, and urban minerals.

4. A smelting method for lead-zinc sulfide materials, characterized in that, Including the steps: S21. Pretreating the lead-zinc sulfide material by the method for pretreating lead-zinc sulfide material according to any one of claims 1 to 3 to obtain a smelting material. S22. Performing oxidative desulfurization treatment on the smelting material to obtain a desulfurized product; the process of the oxidative desulfurization treatment includes converting the smelting material; when the sulfur content in the smelting material <1 wt%, terminating the converting. S23. Performing combined lead-zinc smelting on the mixed slag to obtain metallic lead and metallic zinc.

5. The smelting method of lead-zinc sulfide materials according to claim 4, characterized in that, The converting method includes top blowing, bottom blowing, or side blowing. The oxygen content during the converting process >20%.

6. The smelting method of lead-zinc sulfide materials according to claim 4, characterized in that In step S22, the oxidative desulfurization process is carried out at 1150-1300 °C.

7. The smelting method of lead-zinc sulfide materials according to claim 4, characterized in that In step S23, the combined lead-zinc smelting includes pyrometallurgical lead-zinc smelting and bath smelting. Among them, the pyrometallurgical lead-zinc smelting includes a sintering-sealed blast furnace smelting process.

8. The smelting method of lead-zinc sulfide materials according to claim 7, characterized in that, The bath smelting includes a triple furnace smelting process and a QSL smelting process.

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