Zinc oxygen pressure leaching method combined with flash smelting process

Abstract

The invention relates to a zinc oxygen pressure leaching method combined with a flash smelting process. The zinc oxygen pressure leaching method comprises the following steps: carrying out oxygen pressure leaching on ore pulp obtained by sanding zinc concentrate to obtain first-stage leaching liquid and first-stage leaching residues; adding a neutralizer into the first-section leachate, and separating to obtain supernate and neutralized slag; carrying out flash smelting and fuming on the neutralized slag to obtain multi-hearth furnace zinc oxide, and adding the multi-hearth furnace zinc oxide into a neutralization stirring tank to replace part of the neutralizer for reaction; adding iron powder into the supernate, carrying out copper deposition and dechlorination, adjusting the pH value of the supernate, carrying out fluorine deposition, adding zinc powder, carrying out a replacement reaction, filtering to obtain replaced liquid and replaced slag, carrying out iron removal and purification on the replaced liquid to obtain new liquid and purified slag, and carrying out electrodeposition on the new liquid to obtain metal zinc. According to the method, the oxygen pressure leaching treatment capacity can be improved, the direct recovery rate of various valuable metals and the resource utilization rate can be increased, and environmental pollution is reduced.

Description

Technical Field

[0001] The invention relates to the field of metallurgy, and in particular to a zinc oxygen pressure leaching method combined with a flash smelting process. Background Art

[0002] Oxygen pressure leaching is a modern metallurgical technology method, which is mainly used for the smelting of metal ores such as zinc concentrate. Since the zinc concentrate does not undergo roasting, the oxygen pressure leaching method does not require the construction of a supporting roasting workshop and acid production system, and has high leaching efficiency and strong raw material adaptability. Compared with other smelting methods, it has greater advantages in environmental protection and economy. Its basic principle is to dissolve the metal elements in the ore under the action of high-pressure oxygen. The zinc oxygen pressure leaching process includes the following steps: first, the zinc concentrate is ground into slurry and then sent to an autoclave for pressure leaching, and then neutralized and solid-liquid separated to obtain a neutralized solution and a neutralized slag, and then the neutralized solution is subjected to zinc powder purification, impurity removal, purification, and electrolysis to obtain zinc metal.

[0003] In order to improve the direct recovery rate of zinc, the existing zinc oxygen pressure leaching process usually puts the neutralized slag into the autoclave again for oxygen pressure leaching and then neutralization and solid-liquid separation. However, this will cause arsenic and lead in the neutralized slag to be enriched in the neutralized liquid. In the current oxygen pressure leaching process, arsenic can form insoluble compounds with various metals, which may lead to a decrease in the metal concentration in the leachate. At the same time, arsenic compounds are deposited on the surface of the solid product, which may also hinder the further leaching of zinc. Therefore, the presence of arsenic may affect the leaching rate and selectivity of zinc and other metals. In addition, arsenic compounds may corrode the reactor materials. The presence of arsenic may also increase the corrosion problem in the oxygen pressure leaching process, which may indirectly affect the leaching efficiency. Moreover, arsenic is a toxic element, and an increase in its content may cause environmental pollution.

[0004] In addition, the neutralizer used in the existing zinc oxygen pressure leaching process generally uses zinc oxide and roasted sand produced by traditional processes as neutralizers. However, the zinc oxide and roasted sand produced by traditional roasting furnaces and rotary kiln processes have high iron and silicon contents. After some iron and silicon enter the system solution during the neutralization process, they exist in the form of silicates and iron oxides or hydrated iron alum, which has a great impact on the filtration or dense clarification of the neutralized solution. When iron precipitates, gallium and germanium will also precipitate with the precipitation of iron, which is not conducive to the recovery and impurity removal of valuable metals in the zinc sulfate solution. In order to solve this problem, the neutralizing acid is forced to be increased in production, but the amount of zinc powder is increased in the process of zinc powder replacing valuable metals and removing impurities, which increases the cost, and the amount of slag increases in the later stage. The gallium-germanium slag has a low grade of valuable metals, which is not conducive to comprehensive recovery.

[0005] In summary, the existing zinc oxygen pressure leaching process has the problems of single process, difficulty in achieving comprehensive resource recovery, low direct recovery rate of valuable metals, environmental pollution, etc. Summary of the invention

[0006] Based on this, the purpose of the present invention is to provide a zinc oxygen pressure leaching method combined with a flash smelting process, which can not only effectively improve the direct recovery rate of valuable metals in zinc concentrate and resource utilization, but also improve the efficiency of oxygen pressure leaching treatment and reduce environmental pollution.

[0007] A zinc oxygen pressure leaching method combined with a flash smelting process comprises the following steps:

[0008] Step S1: oxygen pressure acid leaching: the slurry obtained by sand grinding the zinc concentrate is sent to a high pressure autoclave for a stage of oxygen pressure leaching, and then sequentially passes through a flash tank for instantaneous flash evaporation, a regulating tank for temperature and pressure reduction, and a thickening tank for solid-liquid separation to obtain a leachate and a leaching residue;

[0009] Step S2: Neutralization reaction: the first stage leachate is sent to a neutralization stirring tank, a neutralizing agent is added and stirred to perform a continuous neutralization reaction, and then sent to a neutralization thickening tank for separation to obtain a supernatant and a neutralized slag; the neutralizing agent includes a neutralizing acid and zinc oxide;

[0010] Step S3: flash smelting and dechlorination and fluorine precipitation: the neutralized slag is filtered, crushed, dried, and batched, and then sent to a flash smelting furnace for flash smelting and fuming to obtain multi-hearth furnace zinc oxide, and the multi-hearth furnace zinc oxide is sent to the step S2 as the zinc oxide in the neutralizer; iron powder is added to the supernatant and pumped into a copper precipitation and dechlorination reaction tank for copper precipitation and dechlorination, and the pH is adjusted for fluorine precipitation to obtain a dechlorination and fluorine precipitation liquid;

[0011] Step S4: replacement reaction: sending the dechlorination and fluorine precipitation liquid in step S3 to a replacement stirring tank, adjusting the pH, adding zinc powder to carry out a replacement continuous reaction, and then sending it to a filter press for filtration to obtain a replacement liquid and replacement residue;

[0012] Step S5: Purification: removing iron from the replaced liquid and purifying it to obtain new liquid and purified slag;

[0013] Step S6: Electrolytic zinc production: The new solution is electrolytically produced to obtain metallic zinc.

[0014] In the oxygen pressure acid leaching process of step S1 of the present invention, sulfur in zinc sulfide (ZnS) and the like in the zinc concentrate is oxidized into elemental sulfur (S), and zinc is converted into soluble zinc sulfate (ZnSO4); in addition, the first-stage leaching solution contains a large amount of metal ions and acid radical ions, as well as part of fluoride ions (F-) and chloride ions (Cl-) and a small amount of arsenous acid (H3AsO3) and arsenic acid (H3AsO4); the metal ions in the first-stage leaching solution include zinc ions (Zn 2+ ), lead ion (Pb 2+ ), copper ions (Cu 2+ ), gallium ions (Ga 3+ ), Germanium ions (Ge4+ ), calcium ions (Ca 2+ After the neutralizing agent is added in step S2, the zinc oxide reacts with the acid in the first leaching solution to generate salt and water; lead ions (Pb 2+ ) and gallium ions (Ga 3+ ) react with hydroxide ions (OH-) and are converted into insoluble hydroxide precipitates; arsenous acid (H3AsO3) and arsenic acid (H3AsO4) react with zinc ions (Zn 2+ ), calcium ions (Ca 2+ ), copper ions (Cu 2+ ), lead ion (Pb 2+ ) and other metal ions combine to form a precipitate; germanium ions (Ge 4+ ) reacts with hydroxide ions (OH-) to form water-insoluble germanium dioxide (GeO2); fluoride ions (F-) and calcium ions (Ca 2+) combines to form calcium fluoride (CaF2) precipitate; chloride ion (Cl-) combines with various metal cations to form chloride ion type layered double hydroxide precipitate; therefore, the neutralized slag contains hydroxide precipitates such as lead hydroxide precipitate (Pb(OH)2) and gallium hydroxide (Ga(OH)3), calcium arsenate (Ca3(AsO4)2) precipitate, calcium arsenite Ca3(AsO3)2 precipitate and germanium dioxide (GeO2) and other substances. The present invention adopts a flash smelting process to extract and remove lead from the neutralization slag produced in the neutralization step of the zinc oxygen pressure leaching process, and after treatment such as flue gas volatilization to remove arsenic, a multi-hearth furnace zinc oxide with lower iron and silicon contents than the zinc oxide produced by the traditional roasting furnace and rotary kiln process is obtained; the substances in the neutralization slag are thermally decomposed in an ultra-high temperature environment, wherein lead hydroxide (Pb(OH)2) precipitates are thermally decomposed to generate lead oxide (PbO), which then undergoes a reduction reaction with coke to reduce the lead oxide (PbO) to metallic lead (Pb), which is fumed to form smoke dust and is enriched and recovered; the arsenic in the neutralization slag is volatilized into the smoke in the form of As2O3 under high temperature conditions, thereby achieving the effect of arsenic removal; in addition, after the calcium fluoride (CaF2) and chloride ion-type layered double hydroxide precipitates in the neutralization slag are thermally decomposed, the fluorine and chlorine are also volatilized into the smoke dust for recovery treatment. The use of the multi-hearth furnace zinc oxide to replace the zinc oxide in part of the neutralizer and add it to the neutralization stirring tank can reduce the presence of silicates and iron oxides or hydrated iron alum and other compounds in the system solution, which can improve the filtering or thickening and clarifying effect of the supernatant on the one hand, and can further improve the direct recovery rate of valuable metals such as zinc, germanium, and gallium by recycling the multi-hearth furnace zinc oxide on the other hand, thereby improving resource utilization. In addition, the low iron and silicon content can reduce the amount of neutralizing acid in the subsequent step S2 and the amount of zinc powder used in the step S4, thereby reducing production costs and reducing the amount of slag replaced by slag. In addition, the multi-hearth furnace zinc oxide contains a small amount of oxidized lead oxide, which reacts with sulfuric acid in the neutralization process to generate lead sulfate precipitate, thereby reducing sulfate ions in the system during the neutralization reaction process, thereby solving the problem of acid imbalance caused by excessively high acidification rate in step S3, and avoiding the problems of decreased electrolytic efficiency in the subsequent step S6, deterioration of the electrolytic process due to increased viscosity of the new solution, and leaching of a large amount of impurity elements.

[0015] The supernatant obtained after the neutralization in step S2 contains a large amount of zinc ions (Zn 2+ ), sulfate ions, and a small amount of copper ions (Cu 2+) and other metal ions and fluorine ions (F-), chloride ions (Cl-), if they cannot be effectively removed, will cause burning of the subsequent electrolytic process, while reducing the electrical efficiency of the electrolytic process and reducing the quality of the zinc product. Therefore, the supernatant described in step S3 of the present invention is pumped into the copper precipitation dechlorination reaction tank and continuously added with reduced iron powder for copper precipitation dechlorination, and the pH of the supernatant is adjusted to precipitate fluorine; iron powder is added to reduce the copper ions in the supernatant to produce copper element, and the copper element, copper ions, and chloride ions in the supernatant are reacted in an acidic environment by adjusting the pH during the copper precipitation process to produce cuprous chloride precipitation and filtration, thereby achieving the removal of chloride ions; in addition, by controlling the pH of the supernatant, the calcium ions in the supernatant are respectively formed with fluorine and chloride ions to form calcium fluoride and calcium chloride, and the iron ions in the solution are simultaneously formed into a compound precipitation identical to natural goethite (α-FeOOH), and calcium fluoride (CaF2) and calcium chloride (CaCl2) are deposited with iron slag. The present invention cleverly combines the zinc oxygen pressure leaching process with the flash smelting slag treatment process, converts the neutralized slag produced by the oxygen pressure leaching process into multi-hearth furnace zinc oxide with low iron and silicon content through the flash smelting process, removes arsenic and lead in the neutralized slag of the oxygen pressure leaching process, and then re-enters the multi-hearth furnace zinc oxide into the neutralization step of the oxygen pressure leaching process instead of the oxygen pressure acid leaching step. On the one hand, it avoids the enrichment of arsenic and lead when the original neutralized slag enters the oxygen pressure acid leaching step again, which affects the leaching of zinc and other valuable metals, and the environmental pollution caused by arsenic; on the other hand, after the neutralized slag is flash smelted, the multi-hearth furnace zinc oxide obtained is rich in metals such as gallium and germanium and contains a small amount of lead oxide. The re-entry into the neutralization step is conducive to avoiding the precipitation and loss of valuable metal elements such as gallium and germanium in this step, and reducing the zinc powder consumed by the replacement reaction, reducing the production cost, and avoiding the problem of subsequent electrolytic efficiency reduction. After the replacement reaction, valuable metals such as germanium are concentrated in the replacement slag, and the valuable metals can be obtained by recycling the replacement slag. Therefore, the present invention can effectively improve the direct recovery rate of valuable metals and resource utilization rate of zinc concentrate, and can also improve the processing efficiency of the oxygen pressure leaching process and reduce environmental pollution.

[0016] Furthermore, the leaching temperature in the autoclave in step S1 is 145-155°C, the leaching pressure is 1300-1400 KPa, and the acid concentration of the first-stage leaching solution is 15-25 g / L. The above leaching environment is conducive to increasing the entry of valuable metals into the first-stage leaching solution.

[0017] Furthermore, the zinc oxygen pressure leaching method combined with the flash smelting process further includes between step S1 and step S2:

[0018] Step S11: Grind the first-stage leaching residue and send it to the second-stage autoclave for second-stage oxygen pressure leaching, then pass it through the second-stage flash tank for instantaneous flash evaporation, the second-stage regulating tank for cooling and pressure reduction, and the second-stage thickening tank for solid-liquid separation to obtain the second-stage leaching liquid and the second-stage leaching residue; add the second-stage leaching liquid to the ore pulp of step S1.

[0019] Furthermore, the acid concentration in the neutralization stirring tank in step S3 is 5 to 7 g / L.

[0020] Furthermore, the pH value of the supernatant in the displacement stirring tank of step S4 is adjusted to 4.5 to 4.7. In the environment of the above pH value range, the displacement reaction is more complete, which helps to improve the recovery rate of the metal, and is conducive to the gradual removal of impurities in the supernatant, and the solution becomes clearer and purer, which not only helps to improve product quality, but also provides better conditions for subsequent processing and treatment.

[0021] Furthermore, the step S4 also includes: adding calcium carbonate to the replaced liquid for secondary fluorine precipitation.

[0022] Furthermore, the zinc oxygen pressure leaching method combined with the flash smelting process further includes between step S4 and step S5:

[0023] Step S41: the replacement slag is slurried, washed with weak acid, filtered, and then sent to a comprehensive recovery workshop for comprehensive recovery.

[0024] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a flow chart of the zinc oxygen pressure leaching method combined with the flash smelting process. DETAILED DESCRIPTION

[0026] It should be clear that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present application.

[0027] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0028] Zinc in zinc concentrate usually exists in the form of zinc oxide (ZnO) and zinc sulfide (ZnS). In addition, zinc concentrate also contains compounds of various metals, silicon dioxide, and germanium ions (Ge2O3) in the form of isomorphous zinc sulfide (ZnS). 2 + ), gallium ions (Ga 3+ ); generally, the metal compound comprises the following combinations of components:

[0029] Metal oxides: such as iron oxide (FeO, Fe2O3, Fe3O4), magnesium oxide (MgO), copper oxide (CuO), chromium oxide (Cr2O3), antimony oxide (Sb2O5, Sb2O3), As2O5, etc.;

[0030] Metal sulfides: such as sodium sulfide (Na2S), iron sulfide (FeS2), lead sulfide (PbS), copper sulfide (CuS), cadmium sulfide (CdS), nickel sulfide (NiS), cobalt sulfide (CoS), antimony sulfide (Sb2S3), As2S3, FeAsS, etc.;

[0031] Metal fluorides: such as zinc fluoride (ZnF2), etc.

[0032] Metal salts: such as sodium chloride (NaCl), sodium carbonate (NaCO3), sodium sulfate (Na2SO4), etc.;

[0033] Other inorganic salts: arsenate, silicate, etc.

[0034] See also Figure 1 The present invention provides a zinc oxygen pressure leaching method combined with a flash smelting process, comprising the following steps:

[0035] Step S1: oxygen pressure acid leaching: the slurry obtained by sand grinding the zinc concentrate is sent to a high pressure autoclave for a stage of oxygen pressure leaching, and then sequentially passes through a flash tank for instantaneous flash evaporation, a regulating tank for cooling and pressure reduction, and a thickening tank for solid-liquid separation to obtain a leachate and a leaching residue.

[0036] In step S1 of this embodiment, waste liquid containing dilute sulfuric acid is used for leaching, and its acid concentration is 100g / L. The leaching temperature in the autoclave is 155°C and the leaching pressure is 1400KPa. In order to increase the valuable metals entering the zinc sulfate solution, the acid concentration of the first-stage leaching liquid is controlled to be above 15g / L, preferably 15-25g / L; the zinc concentrate contains about 30wt% sulfur, and part of the sulfur element is acidified during the reaction process to produce sulfuric acid, and the acidification rate is about 10%, and the system can maintain acid balance. The first-stage leaching liquid contains a large amount of metal ions and sulfate ions, as well as some fluoride ions (F-) and chloride ions (Cl-) and a small amount of arsenic acid (H3AsO3) and arsenic acid (H3AsO4); the metal ions in the first-stage leaching liquid include zinc ions (Zn 2+ ), lead ion (Pb 2 + ), iron ions (Fe 3+ ), magnesium ion (Mg 2+ ), sodium ion (Na + ), copper ions (Cu 2+ ), cadmium ions (Cd 2+ ), antimony ions (Sb 3+ ), gallium ions (Ga 3+ ), Germanium ions (Ge 4+ ), chromium ion (Cr 3+ ), cobalt ions (Co 2+ ), nickel ions (Ni 2+ ), calcium ions (Ca 2+ )wait.

[0037] Step S11: Grind the first-stage leaching residue and send it to the second-stage autoclave for second-stage oxygen pressure leaching, then pass it through the second-stage flash tank for instantaneous flash evaporation, the second-stage regulating tank for cooling and pressure reduction, and the second-stage thickening tank for solid-liquid separation to obtain the second-stage leaching liquid and the second-stage leaching residue; add the second-stage leaching liquid to the ore pulp of step S1.

[0038] Step S2: Neutralization reaction: the first stage leaching solution is sent to a neutralization stirring tank, a neutralizing agent is added and stirred to carry out a continuous neutralization reaction, and then sent to a thickening tank for separation to obtain a supernatant and a neutralized slag; the neutralizing agent includes a neutralizing acid, zinc oxide or roasted sand.

[0039] In step S2 of this embodiment, after adding the neutralizing agent, the zinc oxide reacts with the acid in the first leaching solution to generate salt and water; the lead ions (Pb 2+ ) and gallium ions (Ga 3+ ) react with hydroxide ions (OH-) and are converted into insoluble hydroxide precipitates; arsenous acid (H3AsO3) and arsenic acid (H3AsO4) react with zinc ions (Zn 2+ ), calcium ions (Ca 2+), copper ions (Cu 2 + ), lead ion (Pb 2+ ) and other metal ions combine to form a precipitate; germanium ions (Ge 4+ ) reacts with hydroxide ions (OH-) to form water-insoluble germanium dioxide (GeO2); fluoride ions (F-) and calcium ions (Ca 2+ ) combines to form calcium fluoride (CaF2) precipitation; chloride ions (Cl-) combine with various metal cations to form chloride ion type layered double metal hydroxide precipitation; therefore, the neutralized slag contains hydroxides such as lead hydroxide (Pb(OH)2) and gallium hydroxide (Ga(OH)3), calcium arsenate (CaAsO4), calcium arsenite Ca3(AsO3)2, germanium dioxide (GeO2), calcium fluoride (CaF2), chloride ion type layered double metal hydroxide and other substances. In addition to a large amount of zinc ions (Zn 2+ ), sulfate ion (SO4 2- ) also contains a small amount of copper ions (Cu 2+ ), iron ions (Fe 3+ ), magnesium ion (Mg 2+ ), sodium ion (Na + ), cadmium ions (Cd 2+ ), antimony ions (Sb 3+ ), chromium ion (Cr 3+ ), cobalt ions (Co 2+ ), nickel ions (Ni 2+ ), calcium ions (Ca 2+ ), gallium ions (Ga 3+ ), Germanium ions (Ge 4+ ) and other metal ions and a small amount of fluoride ions (F-) and chloride ions (Cl-).

[0040] Step S3: Flash smelting and dechlorination and precipitation of fluorine: The neutralized slag is filtered, crushed, dried, and batched, and then sent to a flash smelting furnace for flash smelting and fuming to obtain multi-hearth furnace zinc oxide, and the multi-hearth furnace zinc oxide is sent to the step S2 as the zinc oxide in the neutralizer; iron powder is added to the supernatant and pumped into a copper precipitation and dechlorination reaction tank for copper precipitation and dechlorination, and the pH is adjusted for precipitation of fluorine to obtain a dechlorination and precipitation of fluorine liquid. The multi-hearth furnace zinc oxide is added until the acid concentration in the neutralization stirring tank drops from 15g / L to about 5g / L, preferably 5-7g / L.

[0041] In step S3 of this embodiment, the substances in the neutralized slag are thermally decomposed under an ultra-high temperature environment, wherein the lead hydroxide (Pb(OH)2) precipitate is thermally decomposed to generate lead oxide (PbO), which then undergoes a reduction reaction with coke to reduce the lead oxide (PbO) to metallic lead (Pb), which is fumed to form smoke and is enriched and recovered; the calcium arsenate (Ca3(AsO4)2) precipitate and the calcium arsenite Ca3(AsO3)2 precipitate are thermally decomposed to generate arsenic oxide (As2O3) and calcium oxide (CaO), and the arsenic oxide (As2O3) is volatilized by the flue gas to achieve the removal of arsenic in the neutralized slag. In addition, after the calcium fluoride (CaF2) and chloride ion-type layered double hydroxide precipitate in the neutralized slag are thermally decomposed, the fluorine and chlorine are also volatilized into the smoke for recovery.

[0042] Step S4: Replacement reaction: send the dechlorinated fluorine precipitation liquid in step S3 to a replacement stirring tank, gradually adjust the pH of the supernatant to 4.5-4.7, add zinc powder to carry out replacement continuous reaction, precipitate gallium and germanium metals, and then send it to a filter press for filtration to obtain replacement liquid and replacement residue; slurry the replacement residue and wash it with weak acid, send it to a filter press, and then send it to a comprehensive recovery workshop for comprehensive recovery. Add zinc powder, the copper ions (Cu 2+ ), iron ions (Fe 3+ ), gallium ions (Ga 3+ ), Germanium ions (Ge 4+ ) are reduced to form metal elements.

[0043] As a further improvement of the above scheme, calcium carbonate is added to the replaced liquid at the same time as zinc powder to perform secondary fluoride precipitation. Calcium ions react with fluoride ions in the replaced liquid to form calcium fluoride (CaF2), while iron ions (Fe 3 + ) is hydrolyzed into goethite crystals and calcium fluoride (CaF2) is deposited with the iron slag.

[0044] Step S41: the replacement slag is slurried, washed with weak acid, filtered, and then sent to a comprehensive recovery workshop for comprehensive recovery.

[0045] Step S5: Purification: removing iron from the replaced liquid and purifying it to obtain new liquid and purified slag;

[0046] Step S6: Electrolytic zinc production: The new solution is electrolytically produced to obtain metallic zinc.

[0047] The multi-hearth furnace zinc oxide obtained in step S3 of this embodiment contains about 50wt% zinc, about 0.5wt% germanium, and about 15-20wt% lead oxide; after the multi-hearth furnace zinc oxide is added to the neutralization stirring tank, the zinc leaching rate in the multi-hearth furnace zinc oxide is 85%, the gallium and germanium leaching rates are as high as 90%, the germanium content of the supernatant increases from 15mg / L to about 30mg / L, and the neutralized slag contains about 7wt% zinc and about 0.04wt% germanium. It can be seen that the present invention recovers zinc and germanium in the slag again by flash smelting the neutralized slag as a neutralizing agent and then putting it into the system, thereby improving resource utilization. The fluorine precipitation rate of the supernatant in step S3 reaches 60%. The germanium concentration in the liquid after replacement in step S4 is lower than 2mg / L, and the average germanium content in the replacement slag increases from the original 4.5kg / t to 6.2kg / t, the direct recovery rate of germanium metal increases from 65% to 90%, and the recovery rate of germanium metal is significantly improved. In addition, since the present invention adopts a flash smelting process to process the neutralized slag, the channel for returning the neutralized slag to oxygen leaching in the existing zinc oxygen pressure leaching process is omitted, so the zinc concentrate processing efficiency of the present invention is increased from the original 42t / h to 50t / h, and the zinc ingot production capacity is increased from the original 148,000 tons to 152,000 tons, and the average zinc content of the new liquid in step S6 is reduced from the original 200g / L to 180g / L, which not only improves the oxygen pressure leaching processing efficiency, but also improves the direct recovery rate of various valuable metals such as zinc, gallium, and germanium. The present invention also reduces the dependence on the purchase of high-quality zinc oxide, improves production stability, reduces cost investment, improves the production efficiency of the factory, reduces environmental pollution problems, realizes a green circular economy, has considerable economic, safety, and social benefits, and is of great significance to promoting the sustainable development of the industry.

[0048] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A zinc oxygen pressure leaching method combined with a flash smelting process, characterized in that: The following steps are involved: Step S1: oxygen pressure acid leaching: the slurry obtained by sand grinding the zinc concentrate is sent to a high pressure autoclave for a stage of oxygen pressure leaching, and then sequentially passes through a flash tank for instantaneous flash evaporation, a regulating tank for temperature and pressure reduction, and a thickening tank for solid-liquid separation to obtain a leachate and a leaching residue; Step S2: Neutralization reaction: the first stage leachate is sent to a neutralization stirring tank, a neutralizing agent is added and stirred to perform a continuous neutralization reaction, and then sent to a neutralization thickening tank for separation to obtain a supernatant and a neutralized slag; the neutralizing agent includes a neutralizing acid and zinc oxide; Step S3: flash smelting and dechlorination and fluorine precipitation: the neutralized slag is filtered, crushed, dried, and batched, and then sent to a flash smelting furnace for flash smelting and fuming to obtain multi-hearth furnace zinc oxide, and the multi-hearth furnace zinc oxide is sent to the step S2 as the zinc oxide in the neutralizer; iron powder is added to the supernatant and pumped into a copper precipitation and dechlorination reaction tank for copper precipitation and dechlorination, and the pH is adjusted for fluorine precipitation to obtain a dechlorination and fluorine precipitation liquid; Step S4: replacement reaction: sending the dechlorination and fluorine precipitation liquid in step S3 to a replacement stirring tank, adjusting the pH, adding zinc powder to carry out a replacement continuous reaction, and then sending it to a filter press for filtration to obtain a replacement liquid and replacement residue; Step S5: Purification: removing iron from the replaced liquid and purifying it to obtain new liquid and purified slag; Step S6: Electrolytic zinc production: The new solution is electrolytically produced to obtain metallic zinc.

2. The zinc oxygen pressure leaching method combined with the flash smelting process according to claim 1, characterized in that: The leaching temperature in the autoclave of step S1 is 145-155° C., and the leaching pressure is 1300-1400 Kpa; and the acid concentration of the first-stage leaching liquid is 15-25 g / L.

3. The zinc oxygen pressure leaching method combined with the flash smelting process according to claim 1, characterized in that: The step S1 and the step S2 also include: Step S11: Grind the first-stage leaching residue and send it to the second-stage autoclave for second-stage oxygen pressure leaching, then pass it through the second-stage flash tank for instantaneous flash evaporation, the second-stage regulating tank for cooling and pressure reduction, and the second-stage thickening tank for solid-liquid separation to obtain the second-stage leaching liquid and the second-stage leaching residue; add the second-stage leaching liquid to the ore pulp of step S1.

4. The zinc oxygen pressure leaching method combined with the flash smelting process according to claim 1, characterized in that: The acid concentration in the neutralization stirring tank in step S3 is 5 to 7 g / L.

5. The zinc oxygen pressure leaching method combined with the flash smelting process according to claim 1, characterized in that: The pH value of the supernatant in the replacement stirring tank in step S4 is adjusted to 4.5-4.

7.

6. The zinc oxygen pressure leaching method combined with the flash smelting process according to claim 1, characterized in that: The step S4 further comprises: adding calcium carbonate to the dechlorination and fluorine precipitation liquid for secondary fluorine precipitation.

7. The zinc oxygen pressure leaching method combined with the flash smelting process according to claim 1, characterized in that: The step S4 and the step S5 also include: Step S41: the replacement slag is slurried, washed with weak acid, filtered, and then sent to a comprehensive recovery workshop for comprehensive recovery.

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