A combined leaching method for zinc oxide smoke and zinc roasted sand

Abstract

The present invention relates to a combined leaching method for zinc oxide smoke and zinc roasted sand, belonging to the technical field of hydrometallurgy. The method comprises the following steps: adding zinc oxide smoke to a high-leaching solution for neutral leaching to obtain a medium-leaching residue and a medium-leaching solution; adding zinc roasted sand to a waste electrolyte from hydrometallurgy for weak acid leaching to obtain a weak-leaching residue and a weak-leaching solution; adding the weak-leaching residue to a waste electrolyte from hydrometallurgy for hot acid leaching to obtain a zinc-leaching residue and a hot-acid leaching solution; adding the medium-leaching residue to a mixture of the hot-acid leaching solution and the waste electrolyte from hydrometallurgy for high-acid leaching to obtain a high-leaching solution and a high-leaching residue, wherein the high-leaching residue is lead-silver slag, and the high-leaching solution is returned to a neutral leaching process; mixing the medium-leaching solution and the weak-leaching solution, adding a purifier to perform copper replacement, de-arsenicization, and de-chlorination to obtain a copper-rich, arsenic-chloride slag and a copper precipitation solution; and adding the zinc roasted sand to the copper precipitation solution for neutralization and impurity removal to obtain a neutralized solution and a neutralized residue. The method can effectively improve the leaching rate of zinc from zinc oxide smoke and the leaching rate of copper from zinc roasted sand.

Description

Technical Field

[0001] The invention relates to a combined leaching method of zinc oxide smoke and zinc roasted sand, belonging to the technical field of hydrometallurgy. Background Art

[0002] The traditional hydrometallurgical zinc smelting process involves roasting, leaching (neutral leaching + weak acid leaching), purification, and electrodeposition. Weak acid leaching produces zinc slag. Treatment methods for zinc slag include both pyrometallurgical and hydrometallurgical processes. Pyrometallurgical processes primarily involve rotary kiln volatilization and fuming furnace volatilization. High-temperature reduction and volatilization produce zinc oxide dust, which is then leached. Therefore, zinc roasted sand and zinc oxide dust are two types of zinc-containing materials in traditional hydrometallurgical operations.

[0003] Zinc oxide fume contains sulfides, resulting in low zinc leaching rates. Adding oxidants for high-acid leaching requires high oxidant dosages and poor results. Furthermore, the chloride ions introduced into the solution by the zinc oxide fume require specialized removal processes, typically copper slag dechlorination. This results in a long and complex leaching process, resulting in significant metal losses. Conventional zinc roasted sand leaching processes also suffer from low copper leaching rates and the inability to directly separate and enrich the copper, requiring purification. Summary of the Invention

[0004] Aiming at the problems of long process flow, complex process and low leaching rate in wet leaching of two types of zinc-containing materials, zinc oxide dust and zinc roasted sand, the present invention proposes a combined leaching method of zinc oxide dust and zinc roasted sand. The present invention combines zinc oxide dust and zinc roasted sand for leaching, utilizes the copper-containing solution and trivalent iron-containing solution obtained in the zinc roasted sand leaching process, realizes efficient leaching of zinc oxide dust and impurity removal, improves the leaching rate and recovery rate of valuable metal copper in the two types of zinc-containing materials, zinc oxide dust and zinc roasted sand, and simplifies the removal of arsenic and chlorine in the wet zinc smelting solution.

[0005] A combined leaching method of zinc oxide smoke and zinc roasted sand, comprising the following steps:

[0006] (1) adding zinc oxide smoke to a simulated high-leaching solution for neutral leaching, and performing liquid-solid separation to obtain intermediate leaching residue and intermediate leaching solution; the simulated high-leaching solution is prepared from waste electrolyte of hydrometallurgical zinc smelting and zinc sulfate solution;

[0007] (2) adding zinc roasted sand into the waste electrolyte of wet zinc smelting to carry out weak acid leaching, and liquid-solid separation is performed to obtain weak leaching residue and weak leaching liquid;

[0008] (3) The weak leaching residue from step (2) is added to the waste electrolyte of wet zinc smelting for hot acid leaching, and the liquid-solid separation is performed to obtain zinc leaching residue and hot acid leaching liquid; the zinc leaching residue is sent to pyrometallurgical volatilization treatment;

[0009] (4) the leaching residue in step (1) is added to a high acid solution for high acid leaching, and the liquid-solid separation is performed to obtain a high leaching solution and a high leaching residue, wherein the high leaching residue is a lead-silver residue; the high leaching solution is returned to step (1) to replace the simulated high leaching solution for neutral leaching; the high acid solution is a mixture of hot acid leaching solution and wet refining waste electrolyte;

[0010] (5) mixing the leaching solution in step (1) and the weak leaching solution in step (2), adding a purifier to perform copper precipitation, arsenic removal, and chlorine removal to obtain copper-rich arsenic-chlorine slag and copper precipitation solution;

[0011] (6) The zinc roasted sand is added to the copper precipitation solution in step (5) for neutralization and impurity removal, and the liquid-solid separation is performed to obtain a neutralized solution and a neutralized slag; the neutralized slag is sent to a pyrometallurgical volatilization treatment, and the neutralized solution is sent to a purification electrowinning process.

[0012] In the step (1), the copper content of the zinc oxide fume is greater than 0.5 wt.%, the sulfur content is greater than 2 wt.%, and the chlorine content is less than 0.5 wt.%.

[0013] Preferably, the concentration of sulfuric acid in the simulated high-temperature leaching solution in step (1) is 80-120 g / L, and the solid-liquid ratio (g:mL) of zinc oxide fume to the simulated high-temperature leaching solution is 1:6-8.

[0014] The sulfuric acid concentration in the waste electrolyte of hydrometallurgical zinc smelting is 160-165 g / L.

[0015] Preferably, in step (2), the solid-liquid ratio of zinc roasted sand to the waste electrolyte of hydrometallurgy zinc smelting is g:mL 1:6-7, the weak acid leaching temperature is 80-90°C, the leaching time is 1.5-2h, and the end point pH is 1.5-3; zinc and copper are leached while iron is not leached.

[0016] Preferably, the solid-liquid ratio (g:mL) of the weak leaching residue in step (3) to the waste electrolyte of hydrometallurgical zinc smelting is 1:3-4, the hot acid leaching temperature is 80-90°C, the time is 2-3h, and the final acid is 40-60g / L; during the hot acid leaching process, while leaching zinc and copper, partial iron leaching is controlled to achieve the balance and concentration control of iron in the hot acid leaching solution, and obtain a hot acid leaching solution containing iron and 5-10g / L of trivalent iron.

[0017] Preferably, the concentration of sulfuric acid in the high acid solution in step (4) is 100-150 g / L, the temperature of the high acid leaching is 80-90° C., the time is 3-5 hours, and the final acid is 80-120 g / L; no oxidant is required in the high acid leaching process, and the trivalent iron ions in the hot acid leaching solution are used to leach zinc sulfide in the zinc oxide dust, thereby improving the leaching rate of zinc in the zinc oxide dust.

[0018] Preferably, the purifier in step (5) is zinc-copper-iron alloy powder, which is added according to stoichiometric amount. The temperature for copper displacement precipitation, arsenic removal and chlorine removal is 50-60° C., and the time is 20-30 min. Copper, arsenic and chlorine are separated from the solution in the form of cuprous arsenide and cuprous chloride, respectively.

[0019] Preferably, the specific method for neutralization and impurity removal in step (6) is: zinc roasted sand is added to the copper precipitation solution in step (5); when the pH value of the copper precipitation solution is not greater than 3, hydrogen peroxide is added to oxidize the iron precipitation to generate ferrocyanide and goethite precipitation instead of ferric hydroxide to reduce the amount of neutralization slag; then the pH value of the solution is adjusted to 5.0-5.2, air is introduced to oxidize the iron precipitation and hydrolyze to obtain ferric hydroxide; and impurities are removed by utilizing the adsorption properties of ferrocyanide, goethite and ferric hydroxide to different impurities.

[0020] The beneficial effects of the present invention are:

[0021] (1) The present invention utilizes the copper-containing solution and the ferric iron-containing solution obtained in the zinc roasting sand leaching process to achieve efficient leaching of zinc oxide dust and impurity removal;

[0022] (2) The present invention can achieve efficient leaching of zinc oxide dust and improve the quality of lead-silver slag: the hot acid leaching solution of zinc roasted sand is used for high-acid leaching of zinc oxide dust, and the trivalent iron ions in the hot acid leaching solution are used to leach zinc sulfide in the zinc oxide dust. Without the need for an external oxidant, the zinc leaching rate in the oxide powder can be improved, and at the same time, the amount of lead-silver slag can be reduced, thereby improving the quality of the lead-silver slag;

[0023] (3) The present invention can realize the direct separation and enrichment of copper and the removal of arsenic and chlorine in zinc roasted sand: the zinc oxide dust leaching solution is mixed with the zinc roasted sand weak acid solution to achieve the purpose of adjusting the pH at the same time, and the copper is replaced by precipitation to remove arsenic and chlorine. During the leaching process, the copper is separated and enriched as a marketable copper slag, avoiding the precipitation loss of copper caused by the return of weak acid leaching to the intermediate leaching in the traditional process and simplifying the subsequent purification process. At the same time, when the copper is converted into cuprous ions, the arsenic and chlorine in the solution are converted into precipitates and removed from the solution, thereby realizing the efficient utilization and recovery of copper and the simultaneous removal of arsenic and chlorine, and avoiding the need for a separate copper slag dechlorination process;

[0024] (4) The present invention can achieve the reduction of zinc roasted sand leaching residue and the opening of impurities in the liquid before purification: the iron in the zinc roasted sand hot acid leaching liquid does not return to the zinc roasted sand leaching system, and the iron is opened from the roasted sand leaching system, thereby reducing the amount of zinc leaching residue; the copper precipitation liquid controls the solution acidity in stages during the neutralization process, and the iron in the copper precipitation liquid is converted into iron alum, goethite, and iron hydroxide during the neutralization process instead of completely oxidizing the iron to precipitate iron hydroxide colloid, thereby reducing the amount of neutralization residue (and the sum of the neutralization residue and the zinc leaching residue is less than the amount of leaching residue in the traditional leaching process), and at the same time, utilizes the adsorption of different iron precipitates relative to different impurities to perform deep removal of impurities in the solution, so as to facilitate subsequent solution purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0027] Example 1: The main components (wt%) of zinc oxide smoke in this example are: Zn: 54.85, Fe: 2.58, S: 3.19, Pb: 10.28, Ag: 0.0485, Cl: 0.51; the main components (wt%) of zinc calcine are: Zn: 50.27, Fe: 10.16, S: 2.53, Cu: 0.85, Pb: 1.98, Ag: 0.068; the waste electrolyte from hydrometallurgy zinc smelting contains 45.28 g / L zinc and 160.51 g / L sulfuric acid;

[0028] A combined leaching method of zinc oxide smoke and zinc roasted sand (see Figure 1 ), the specific steps are as follows:

[0029] (1) Zinc oxide smoke is added to a simulated high leaching solution for neutral leaching, and liquid-solid separation is performed to obtain intermediate leaching residue and intermediate leaching solution;

[0030] The simulated high-temperature leaching solution is prepared from waste electrolyte of hydrometallurgical zinc smelting and zinc sulfate solution, the sulfuric acid concentration in the simulated high-temperature leaching solution is 105 g / L, and the solid-liquid ratio of zinc oxide smoke to simulated high-temperature leaching solution is 1:6.2 g:mL;

[0031] (2) adding zinc calcine to the waste electrolyte of hydrometallurgy for weak acid leaching, and performing liquid-solid separation to obtain weak leaching residue and weak leaching liquid; the solid-liquid ratio (g:mL) of the zinc calcine to the waste electrolyte of hydrometallurgy is 1:7, the temperature of weak acid leaching is 80°C, the time is 2h, the end point pH is 1.5, zinc and copper are leached while iron is not leached, and weak leaching residue and weak leaching liquid are obtained;

[0032] (3) The weak leaching residue from step (2) is added to the waste electrolyte of zinc hydrometallurgy for hot acid leaching, and the zinc leaching residue and the hot acid leaching solution are obtained by liquid-solid separation; the zinc leaching residue is sent to a pyrometallurgical volatilization treatment to obtain zinc oxide smoke; the solid-liquid ratio g:mL of the weak leaching residue and the waste electrolyte of zinc hydrometallurgy is 1:4, the hot acid leaching temperature is 90°C, the time is 2h, and the final acid is 50g / L; during the hot acid leaching process, while leaching zinc and copper, partial iron leaching is controlled to achieve balance and concentration control of iron in the hot acid leaching solution, and a hot acid leaching solution containing iron and 9.6g / L of trivalent iron is obtained;

[0033] (4) the leaching residue in step (1) is added to a high acid solution for high acid leaching, and the liquid-solid separation is performed to obtain a high leaching solution and a high leaching residue, wherein the high leaching residue is a lead-silver residue; the high leaching solution is returned to step (1) to replace the simulated high leaching solution for neutral leaching; the high acid solution is a mixture of hot acid leaching solution and wet refining waste electrolyte, the sulfuric acid concentration in the high acid solution is 123 g / L, the high acid leaching temperature is 80° C., the time is 5 h, and the final acid is 100 g / L; no oxidant is added during the high acid leaching process, and the trivalent iron ions in the hot acid leaching solution are used to leach zinc sulfide in the zinc oxide smoke, thereby improving the leaching rate of zinc in the zinc oxide smoke;

[0034] (5) the leaching solution in step (1) and the weak leaching solution in step (2) are mixed, and a purifier (zinc-copper-iron alloy powder) is added to perform copper displacement precipitation, arsenic removal, and chlorine removal to obtain copper-rich arsenic-chlorine slag and copper precipitation solution; the purifier (zinc-copper-iron alloy powder) is added according to a stoichiometric amount, the temperature for copper displacement precipitation, arsenic removal, and chlorine removal is 60° C. for 20 minutes, and the copper, arsenic, and chlorine are separated from the solution in the form of cuprous arsenide and cuprous chloride, respectively;

[0035] (6) zinc roasted sand is added to the copper precipitation solution of step (5) for neutralization and impurity removal, and liquid-solid separation is performed to obtain a neutralized solution and a neutralized slag; the neutralized solution is sent to a purification electrolytic process; the neutralized slag is sent to a pyrometallurgical volatilization treatment to obtain zinc oxide smoke; the specific method of neutralization and impurity removal (two-step method) is as follows: zinc roasted sand is added to the copper precipitation solution of step (5); when the pH value of the copper precipitation solution is not greater than 3, hydrogen peroxide (oxidant) is added to oxidize the precipitated iron to generate ferroalloy and goethite precipitation instead of ferric hydroxide to reduce the amount of neutralized slag; then the pH value of the solution is adjusted to 5.0-5.2, air is introduced to oxidize the remaining iron in the precipitate and hydrolyze to obtain ferric hydroxide; impurities are removed by utilizing the adsorption properties of ferroalloy, goethite and ferric hydroxide to different impurities;

[0036] In this embodiment, the zinc leaching rate in the zinc oxide fume is 94.12%, and the lead-silver slag rate is 31.05%; the zinc leaching rate in the zinc roasted sand is 93.52%, the copper leaching rate is 75.63%, and the zinc leaching slag rate is 28.83%; the copper content in the copper-arsenic-chlorine slag is 52.23%, the copper precipitation rate is 99.67%, the arsenic removal rate is 90.22%, and the chlorine removal rate is 60.34%.

[0037] Example 2: The zinc oxide dust, zinc calcine, and waste electrolyte of hydrozinc smelting in this example are the same as those in Example 1;

[0038] A combined leaching method of zinc oxide smoke and zinc roasted sand (see Figure 1 ), the specific steps are as follows:

[0039] (1) Zinc oxide smoke is added to a simulated high leaching solution for neutral leaching, and liquid-solid separation is performed to obtain intermediate leaching residue and intermediate leaching solution;

[0040] The simulated high-temperature leaching solution is prepared from waste electrolyte of hydrometallurgical zinc smelting and zinc sulfate solution, the sulfuric acid concentration in the simulated high-temperature leaching solution is 118 g / L, and the solid-liquid ratio of zinc oxide smoke to simulated high-temperature leaching solution is 1:7.1 (g:mL);

[0041] (2) adding zinc calcine to the waste electrolyte of hydrometallurgy for weak acid leaching, and performing liquid-solid separation to obtain weak leaching residue and weak leaching liquid; the solid-liquid ratio (g:mL) of the zinc calcine to the waste electrolyte of hydrometallurgy is 1:6.5, the temperature of weak acid leaching is 85°C, the time is 1.5h, the end point pH is 2.3, zinc and copper are leached while iron is not leached, and weak leaching residue and weak leaching liquid are obtained;

[0042] (3) the weak leaching residue from step (2) is added to the waste electrolyte of zinc hydrometallurgy for hot acid leaching, and the zinc leaching residue and the hot acid leaching solution are obtained by liquid-solid separation; the zinc leaching residue is sent to a pyrometallurgical volatilization treatment to obtain zinc oxide smoke; the solid-liquid ratio g:mL of the weak leaching residue and the waste electrolyte of zinc hydrometallurgy is 1:3.5, the hot acid leaching temperature is 80°C, the time is 3h, and the final acid is 40g / L; during the hot acid leaching process, while leaching zinc and copper, partial iron leaching is controlled to achieve balance and concentration control of iron in the hot acid leaching solution, and a hot acid leaching solution containing iron and 7.8g / L of trivalent iron is obtained;

[0043] (4) the leaching residue in step (1) is added to a high acid solution for high acid leaching, and the liquid-solid separation is performed to obtain a high leaching solution and a high leaching residue, wherein the high leaching residue is a lead-silver residue; the high leaching solution is returned to step (1) to replace the simulated high leaching solution for neutral leaching; the high acid solution is a mixture of hot acid leaching solution and wet refining waste electrolyte, the sulfuric acid concentration in the high acid solution is 149 g / L, the high acid leaching temperature is 85° C., the time is 3 h, and the final acid is 120 g / L; no oxidant is added during the high acid leaching process, and the trivalent iron ions in the hot acid leaching solution are used to leach zinc sulfide in the zinc oxide smoke, thereby improving the leaching rate of zinc in the zinc oxide smoke;

[0044] (5) the leaching solution in step (1) and the weak leaching solution in step (2) are mixed, and a purifier (zinc-copper-iron alloy powder) is added to perform copper displacement precipitation, arsenic removal, and chlorine removal to obtain copper-rich arsenic-chlorine slag and copper precipitation solution; the purifier (zinc-copper-iron alloy powder) is added according to a stoichiometric amount, the temperature for copper displacement precipitation, arsenic removal, and chlorine removal is 55° C. for 25 minutes, and the copper, arsenic, and chlorine are separated from the solution in the form of cuprous arsenide and cuprous chloride, respectively;

[0045] (6) zinc roasted sand is added to the copper precipitation solution of step (5) for neutralization and impurity removal, and liquid-solid separation is performed to obtain a neutralized solution and a neutralized slag; the neutralized solution is sent to a purification electrolytic process; the neutralized slag is sent to a pyrometallurgical volatilization treatment to obtain zinc oxide smoke; the specific method of neutralization and impurity removal (two-step method) is as follows: zinc roasted sand is added to the copper precipitation solution of step (5); when the pH value of the copper precipitation solution is not greater than 3, hydrogen peroxide (oxidant) is added to oxidize the precipitated iron to generate ferroalloy and goethite precipitation instead of ferric hydroxide to reduce the amount of neutralized slag; then the pH value of the solution is adjusted to 5.0-5.2, air is introduced to oxidize the remaining iron in the precipitate and hydrolyze to obtain ferric hydroxide; impurities are removed by utilizing the adsorption properties of ferroalloy, goethite and ferric hydroxide to different impurities;

[0046] In this embodiment, the zinc leaching rate in the zinc oxide fume is 95.68%, and the lead-silver slag rate is 29.75%; the zinc leaching rate in the zinc roasted sand is 92.08%, the copper leaching rate is 73.17%, and the zinc leaching slag rate is 30.15%; the copper content in the copper-arsenic-chlorine slag is 50.68%, the copper precipitation rate is 99.89%, the arsenic removal rate is 90.85%, and the chlorine removal rate is 63.53%.

[0047] Example 3: The zinc oxide dust, zinc calcine, and waste electrolyte of hydrometallurgical zinc smelting in this example are the same as those in Example 1;

[0048] A combined leaching method of zinc oxide smoke and zinc roasted sand (see Figure 1 ), the specific steps are as follows:

[0049] (1) Zinc oxide smoke is added to a simulated high leaching solution for neutral leaching, and liquid-solid separation is performed to obtain intermediate leaching residue and intermediate leaching solution;

[0050] The simulated high-temperature leaching solution is prepared from waste electrolyte of hydrometallurgical zinc smelting and zinc sulfate solution, the sulfuric acid concentration in the simulated high-temperature leaching solution is 82 g / L, and the solid-liquid ratio of zinc oxide smoke to simulated high-temperature leaching solution is 1:8 (g:mL);

[0051] (2) adding zinc calcine to the waste electrolyte of hydrometallurgy for weak acid leaching, and performing liquid-solid separation to obtain weak leaching residue and weak leaching liquid; the solid-liquid ratio (g:mL) of the zinc calcine to the waste electrolyte of hydrometallurgy is 1:6.8, the temperature of weak acid leaching is 90°C, the time is 2h, the end point pH is 1.5, zinc and copper are leached while iron is not leached, and weak leaching residue and weak leaching liquid are obtained;

[0052] (3) the weak leaching residue from step (2) is added to the waste electrolyte of zinc hydrometallurgy for hot acid leaching, and the zinc leaching residue and the hot acid leaching solution are obtained by liquid-solid separation; the zinc leaching residue is sent to a pyrometallurgical volatilization treatment to obtain zinc oxide smoke; the solid-liquid ratio g:mL of the weak leaching residue and the waste electrolyte of zinc hydrometallurgy is 1:3, the hot acid leaching temperature is 85°C, the time is 2.5h, and the final acid is 30g / L; during the hot acid leaching process, while leaching zinc and copper, partial iron leaching is controlled to achieve balance and concentration control of iron in the hot acid leaching solution, and a hot acid leaching solution containing iron and 5.7g / L of trivalent iron is obtained;

[0053] (4) the leaching residue in step (1) is added to a high acid solution for high acid leaching, and the liquid-solid separation is performed to obtain a high leaching solution and a high leaching residue, wherein the high leaching residue is a lead-silver residue; the high leaching solution is returned to step (1) to replace the simulated high leaching solution for neutral leaching; the high acid solution is a mixture of hot acid leaching solution and wet refining waste electrolyte, the sulfuric acid concentration in the high acid solution is 103 g / L, the high acid leaching temperature is 90° C., the time is 4 h, and the final acid is 80 g / L; no oxidant is added during the high acid leaching process, and the trivalent iron ions in the hot acid leaching solution are used to leach zinc sulfide in the zinc oxide smoke, thereby improving the leaching rate of zinc in the zinc oxide smoke;

[0054] (5) the leaching solution in step (1) and the weak leaching solution in step (2) are mixed, and a purifier (zinc-copper-iron alloy powder) is added to perform copper displacement precipitation, arsenic removal, and chlorine removal to obtain copper-rich arsenic-chlorine slag and copper precipitation solution; the purifier (zinc-copper-iron alloy powder) is added according to a stoichiometric amount, the temperature for copper displacement precipitation, arsenic removal, and chlorine removal is 50° C. for 30 minutes, and copper, arsenic, and chlorine are separated from the solution in the form of cuprous arsenide and cuprous chloride, respectively;

[0055] (6) zinc roasted sand is added to the copper precipitation solution of step (5) for neutralization and impurity removal, and liquid-solid separation is performed to obtain a neutralized solution and a neutralized slag; the neutralized solution is sent to a purification electrolytic process; the neutralized slag is sent to a pyrometallurgical volatilization treatment to obtain zinc oxide smoke; the specific method of neutralization and impurity removal (two-step method) is as follows: zinc roasted sand is added to the copper precipitation solution of step (5); when the pH value of the copper precipitation solution is not greater than 3, hydrogen peroxide (oxidant) is added to oxidize the precipitated iron to generate ferroalloy and goethite precipitation instead of ferric hydroxide to reduce the amount of neutralized slag; then the pH value of the solution is adjusted to 5.0-5.2, air is introduced to oxidize the remaining iron in the precipitate and hydrolyze to obtain ferric hydroxide; impurities are removed by utilizing the adsorption properties of ferroalloy, goethite and ferric hydroxide to different impurities;

[0056] In this embodiment, the zinc leaching rate in the zinc oxide fume is 92.35%, and the lead-silver slag rate is 33.21%; the zinc leaching rate in the zinc roasted sand is 90.68%, the copper leaching rate is 70.52%, and the zinc leaching slag rate is 31.29%; the copper content in the copper-arsenic-chlorine slag is 53.16%, the copper precipitation rate is 99.76%, the arsenic removal rate is 90.39%, and the chlorine removal rate is 61.28%.

[0057] The above describes the specific embodiments of the present invention in detail, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the scope of the present invention.

Claims

1. A combined leaching method of zinc oxide smoke and zinc roasted sand, characterized in that: The specific steps are as follows: (1) Zinc oxide fume is added to a simulated high-leaching solution for neutral leaching, and liquid-solid separation is performed to obtain intermediate leaching residue and intermediate leaching solution; the simulated high-leaching solution is prepared from waste electrolyte of hydrometallurgical zinc smelting and zinc sulfate solution; the concentration of sulfuric acid in the simulated high-leaching solution is 80-120 g / L, and the solid-liquid ratio of zinc oxide fume to simulated high-leaching solution is 1:6-8 (g:mL); the concentration of sulfuric acid in the waste electrolyte of hydrometallurgical zinc smelting is 160-165 g / L; the sulfur content of the zinc oxide fume is greater than 2 wt%, and the chlorine content is less than 0.5 wt%. (2) adding zinc roasted sand to the waste electrolyte of zinc hydrometallurgy for weak acid leaching, and performing liquid-solid separation to obtain weak leaching residue and weak leaching solution; the solid-liquid ratio of the zinc roasted sand to the waste electrolyte of zinc hydrometallurgy is 1:6-7 g:mL, the weak acid leaching temperature is 80-90°C, the leaching time is 1.5-2h, and the end point pH is 1.5-3; (3) The weak leaching residue from step (2) is added to the waste electrolyte of zinc hydrometallurgy for hot acid leaching, and the liquid-solid separation is performed to obtain zinc leaching residue and hot acid leaching solution; the zinc leaching residue is sent to a pyrometallurgical volatilization treatment; the solid-liquid ratio g:mL of the weak leaching residue and the waste electrolyte of zinc hydrometallurgy is 1:3-4, the hot acid leaching temperature is 80-90°C, the time is 2-3h, and the final acid is 40-60g / L; (4) adding the leaching residue from step (1) into a high acid solution for high acid leaching, and performing liquid-solid separation to obtain a high acid leaching solution and a high acid leaching residue, wherein the high acid leaching residue is a lead-silver residue; The high-acid leaching solution is returned to step (1) to replace the simulated high-acid leaching solution for neutral leaching; the high-acid solution is a mixture of hot acid leaching solution and wet-process waste electrolyte; the sulfuric acid concentration in the high-acid solution is 100-150 g / L, the high-acid leaching temperature is 80-90°C, the time is 3-5 hours, and the final acid is 80-120 g / L. No oxidant is added during the high-acid leaching process, and the trivalent iron ions in the hot acid leaching solution are used to leach zinc sulfide in the zinc oxide dust to increase the leaching rate of zinc in the zinc oxide dust; (5) mixing the medium leaching solution of step (1) and the weak leaching solution of step (2), adding a purifier to perform copper precipitation, arsenic removal and chlorine removal to obtain copper-rich arsenic-chlorine slag and copper precipitation solution; (6) zinc roasted sand is added to the copper precipitation solution in step (5) for neutralization and impurity removal, and liquid-solid separation is performed to obtain a neutralized solution and a neutralized slag; the neutralized slag is sent to a pyrometallurgical volatilization process, and the neutralized liquid is sent to a purification electrolytic process; the specific method of the neutralization and impurity removal is as follows: zinc roasted sand is added to the copper precipitation solution in step (5), and when the pH value of the copper precipitation solution is not greater than 3, hydrogen peroxide is added to oxidize the iron precipitation to generate iron alum and goethite precipitation; the pH value of the solution is then adjusted to 5.0-5.2, and air is introduced to oxidize the iron precipitation and hydrolyze to obtain ferric hydroxide.

2. according to claim 1 the described zinc oxide smoke and zinc calcine combined leaching method, it is characterized in that: In step (5), the purifier is zinc-copper-iron alloy powder, and the temperature for copper replacement, arsenic removal and chlorine removal is 50-60°C, and the time is 20-30 minutes.

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