A method for co-leaching high-silicon zinc roasted ore with high-sulfur zinc oxide powder

Abstract

This invention relates to a method for the combined leaching of high-silicon zinc roasted ore and high-sulfur zinc oxide powder, belonging to the field of hydrometallurgical technology. The high-sulfur zinc oxide powder is leached neutrally to obtain zinc oxide leaching residue and zinc powder leaching solution. The zinc powder leaching solution is then mixed with high-silicon zinc roasted ore slurry for controlled silica leaching of the high-silicon zinc roasted ore to obtain zinc ore leaching residue and zinc ore leaching solution. The zinc powder leaching residue and zinc ore leaching residue are mixed and then subjected to low-acid leaching to obtain low-leaching residue and low-leaching solution. The low-leaching residue is then subjected to hot acid leaching to obtain hot-leaching residue and hot-leaching solution. The hot-acid residue is then subjected to high-acid leaching to obtain lead-silver slag product and high-leaching solution. The hot-leaching solution is neutralized and reduced by high-sulfur zinc oxide powder to obtain neutralized solution and neutralized residue. The neutralized solution is then subjected to mineralization and iron precipitation to obtain hematite product and iron-removed solution. This invention can effectively control the leaching of silicon in the high-silicon zinc roasted ore leaching process, and simultaneously realize the oxidative leaching of sulfides in zinc oxide powder and the reductive leaching of zinc ferrite in zinc roasted ore, thus simplifying the leaching process of zinc roasted ore and zinc oxide powder.

Description

Technical Field

[0001] This invention relates to a method for the combined leaching of high-silicon zinc roasted ore and high-sulfur zinc oxide powder, belonging to the field of hydrometallurgical technology. Background Technology

[0002] Zinc smelting is primarily hydrometallurgical, accounting for over 85% of global zinc production. The conventional hydrometallurgical zinc smelting process involves roasting, leaching (neutral leaching + weak acid leaching), purification, and electrowinning. The zinc leaching dross produced after weak acid leaching mainly consists of zinc ferrite. Zinc leaching dross treatment methods include pyrometallurgical and hydrometallurgical processes. Pyrometallurgical processes mainly involve rotary kiln volatilization and fuming furnace volatilization, which are highly adaptable to raw materials but have high energy consumption, a heavy environmental burden, and relatively low valuable metal recovery rates.

[0003] Hot acid and high-acid leaching can effectively destroy zinc ferrite in zinc leaching residue, achieving efficient zinc leaching. However, when the zinc leaching rate increases to 95%, the iron leaching rate also reaches over 95%, and most of the iron is in the form of Fe. 3+ Since iron exists in its precipitate form, zinc and iron separation is required in the solution. Iron removal methods are classified according to the precipitate form of iron in the solution: the jaundice method, the goethite method, and the hematite method. When using the goethite or hematite method for iron removal, the Fe in the solution must be removed. 3+ Reduced to Fe 2+ Currently, sulfur dioxide and zinc sulfide concentrate are the reducing agents applicable to industrial production. Sulfur dioxide leaching has the advantages of high reduction efficiency and thorough reduction; however, it introduces sulfate ions during the reduction process. To achieve acid balance, lime is needed for neutralization, producing gypsum slag to balance the sulfate ions introduced by sulfur dioxide reduction. Zinc sulfide concentrate, as a reducing agent, has advantages such as low investment and low operating costs; however, atmospheric pressure reduction of zinc sulfide concentrate has relatively low reduction efficiency, and the reduction leaching residue consists of unreacted zinc concentrate and elemental sulfur, requiring secondary treatment.

[0004] In addition, the zinc roasted sand obtained from the fluidized bed roasting of high-silicon zinc sulfide concentrate contains not only a large amount of zinc ferrite, but also a high content of silicon. Effective control measures need to be taken for the leaching of high-silicon zinc roasted sand to minimize the amount of silicon entering the leachate, so as to ensure the sedimentation, filtration and subsequent purification effects of the slurry.

[0005] my country has large reserves of low-grade lead-zinc oxide ores. Current technologies employ a photoelectric waste disposal-pyrometallurgical volatilization enrichment route to obtain zinc-lead-sulfur-containing zinc oxide powder. However, due to the high silicon and sulfur content in low-grade lead-zinc oxide ores, the mineralogical characteristics of the resulting zinc oxide powder are completely different from those obtained through pyrometallurgical volatilization of wet zinc leaching residue. In particular, the sulfur content reaches 5-7%, while the contents of silver, indium, and germanium are extremely low. Therefore, it is urgent to address the issues of sulfide leaching in high-sulfur zinc oxide powder to achieve efficient leaching and resource utilization of the leaching residue. Summary of the Invention

[0006] To address the issues of low leaching rate of high-sulfur zinc oxide powder and the control of silicon and reduction leaching of zinc ferrite during the leaching process of high-silicon zinc roasted ore, this invention proposes a method for the joint leaching of high-silicon zinc roasted ore and high-sulfur zinc oxide powder. This method effectively controls the leaching of silicon during the leaching process of high-silicon zinc roasted ore, simultaneously achieving the oxidative leaching of sulfides in zinc oxide powder and the reduction leaching of zinc ferrite in zinc roasted ore. This simplifies the leaching process of zinc roasted ore and zinc oxide powder, improves the zinc leaching rate, and enhances the quality of lead-silver slag.

[0007] A method for co-leaching high-silicon zinc roasted ore with high-sulfur zinc oxide powder, the specific steps of which are as follows:

[0008] (1) High-sulfur zinc oxide powder is added to waste electrolyte for neutral leaching to obtain zinc oxide powder leaching residue and zinc powder leaching solution;

[0009] (2) The zinc powder leaching solution is mixed with high-silicon zinc calcined sand to obtain a slurry. Air is introduced to oxidize the ferrous ions in the slurry. A simulated low leaching solution prepared by wet zinc smelting waste electrolyte and zinc sulfate solution is added. At a temperature of 70-80℃ and an initial pH of 2.5-3.0, the wet zinc smelting waste electrolyte is slowly added to control the pH of the slurry to 1.5-2.0 and react for 1-1.5 hours. High-silicon zinc calcined sand is slowly added to control the pH of the slurry to 5.0-5.2 and react for 1-1.5 hours to achieve zinc leaching and avoid the formation of silica gel. The zinc ore leaching residue and zinc ore leaching solution are obtained. The zinc ore leaching solution is sent to the wet zinc smelting purification process.

[0010] (3) After the leaching residue in zinc powder is mixed with the leaching residue in zinc ore, a simulated iron removal solution prepared by wet zinc smelting waste electrolyte and zinc sulfate solution is added for low acid leaching to obtain low leaching residue and low leaching solution. The low leaching solution is returned to step (2) to replace the simulated low leaching solution. Low acid leaching can cause the iron in the iron removal solution to form goethite-like precipitates and enter the low leaching residue.

[0011] (4) The low-leaching residue is added to the simulated high-leaching solution prepared by wet zinc smelting waste electrolyte and zinc sulfate solution, and hot acid leaching is carried out to obtain hot leaching residue and hot leaching solution; hot acid leaching simultaneously realizes the oxidative leaching of sulfides and the reductive leaching of zinc ferrite.

[0012] (5) Add the hot acid slag to the wet zinc smelting waste electrolyte for high acid leaching to obtain high leaching solution and lead-silver slag. The high leaching solution is returned to step (4) to replace the simulated high leaching solution.

[0013] (6) The hot leaching liquid is neutralized and reduced by high sulfur zinc oxide powder to obtain neutralized liquid and neutralized residue. The neutralized residue is returned to step (4) and combined with the low leaching residue for hot acid leaching.

[0014] (7) The neutralized liquid is subjected to low-temperature hematite removal for 3-4 hours at a temperature of 150-160℃ and an oxygen partial pressure of 0.3-0.5MPa to obtain hematite product and iron removal liquid. The iron removal liquid is returned to step (3) to replace the simulated iron removal liquid.

[0015] The sulfur content in the high-sulfur zinc oxide powder of step (1) is greater than 5 wt%.

[0016] Step (1) does not require the addition of an oxidant to precipitate iron. The solid-liquid ratio of high-sulfur zinc oxide powder to waste electrolyte is 1:4 to 4.2 (g:mL). The temperature for neutral leaching is 70 to 80°C, the time is 1.5 to 2 hours, and the final pH is 4.8 to 5.1.

[0017] When preparing the zinc powder immersion solution and high-silicon zinc calcined sand slurry in step (2), the mass ratio of high-silicon zinc calcined sand to high-sulfur zinc oxide powder in step (1) is 1:0.75-0.80; the simulated low immersion solution contains 119-122 g / L of zinc, 0.51-0.55 g / L of iron, and has a pH value of 2.57-2.96.

[0018] In step (3), the simulated solution after iron removal contains 26-29 g / L of sulfuric acid, 112-116 g / L of zinc, and 2.37-2.95 g / L of iron. The low-acid leaching temperature is 80-90℃, the time is 1.5-2h, and the pH of the leaching system is 2.5-3.5.

[0019] Step (4) simulates a high-temperature leaching solution containing 102-118 g / L of sulfuric acid, 52-61 g / L of zinc, and 7.51-7.82 g / L of iron. The hot acid leaching temperature is 80-90℃, the time is 2.0-2.5 h, and the final pH is 0.3-0.5.

[0020] The high acid leaching in step (5) is carried out at a temperature of 80-90°C for 2.5-3.0 hours, with an endpoint sulfuric acid concentration of 100-120 g / L.

[0021] In step (6), the amount of high-sulfur zinc oxide powder added is 23-27% of the mass of the high-sulfur zinc oxide powder in step (1). The neutralization and reduction temperature is 80-90℃, the solution pH is 4.0-5.0, and the Fe content in the neutralization solution is... 3+ Less than 0.2 g / L.

[0022] After iron removal in step (7), the iron concentration in the liquid is less than 3 g / L.

[0023] The beneficial effects of this invention are:

[0024] (1) Utilization of iron and control of silicon leaching: Conventional neutral leaching of zinc oxide powder usually produces zinc powder leaching solution containing 2-5 g / L of iron, and almost all of it is ferrous ions. In this invention, the zinc powder leaching solution is used as the slurry for high-silicon zinc roasted ore. Before the zinc roasted ore is leached, sufficient air is blown in to oxidize the ferrous ions in the slurry to ferric iron, which increases the initial ferric iron content of the leaching ore slurry. At the same time, the pH of the reaction system in the leaching process is controlled in three steps during the zinc roasted ore leaching process, which effectively avoids silicon entering the leaching solution and avoids the formation of silica gel, achieving a better effect of impurity removal and liquid-solid separation.

[0025] (2) Simultaneous Reduction Leaching of Sulfide Oxidation and Zinc Ferrite: In this invention, the unleached zinc in the leaching residue of zinc roasted ore is mainly in the form of zinc ferrite, while the unleached zinc in the leaching residue of zinc oxide powder is mainly in the form of zinc sulfide. During low-acid leaching, the leaching residue from the mixture of these two types further leaches readily soluble zinc other than zinc ferrite and zinc sulfide, resulting in the enrichment of zinc ferrite and zinc sulfide in the low-acid leaching residue. By utilizing the zinc ferrite and zinc sulfide already present in the low-acid leaching residue, sulfide oxidation and zinc ferrite reduction leaching are simultaneously carried out during hot acid and high-acid leaching processes, effectively improving the zinc leaching rate of zinc roasted ore and zinc oxide powder.

[0026] (3) Improved quality of lead-silver slag: High-acid leaching slag (i.e., lead-silver slag) obtained from the separate leaching process of zinc roasted ore usually has a low lead content and is sold based solely on its silver content. The mineralogical characteristics of zinc oxide powder obtained from the pyrolysis of low-grade oxidized lead-zinc ore are completely different from those of zinc oxide powder obtained from the pyrolysis of wet zinc leaching slag. Zinc oxide powder obtained from the pyrolysis of zinc leaching slag usually contains one or more rare and precious metals such as silver, germanium, etc., while the content of rare and precious metals in zinc oxide powder obtained from the pyrolysis of low-grade oxidized lead-zinc ore is relatively low. The high-acid leaching slag (i.e., lead-silver slag) obtained from its separate leaching process is sold based solely on its lead content. This invention, through a combined leaching process, increases the lead and silver content in the high-acid leaching slag (i.e., lead-silver slag), so that the lead and silver content in the final lead-silver slag both meet the minimum market pricing requirements. Attached Figure Description

[0027] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0029] Example 1: The main components (wt%) of high-silicon zinc calcined ore are: Zn: 54.23, Fe: 8.97, S: 2.75, Si: 3.15, Cu: 0.06, In: 0.0031, Pb: 2.19, Ag: 0.012; the main components (wt%) of high-sulfur zinc oxide powder are: Zn: 45.16, Fe: 2.58, S: 7.23, Si: 1.91, Cu: 0.01, In: 0.0075, Pb: 10.28, Ag: 0.0031; the waste electrolyte from wet zinc smelting contains 41.28 g / L of zinc and 165.39 g / L of sulfuric acid.

[0030] A method for co-leaching high-silicon zinc roasted ore with high-sulfur zinc oxide powder (see...) Figure 1 The specific steps are as follows:

[0031] (1) High-sulfur zinc oxide powder was added to the waste electrolyte without the need for oxidant precipitation of iron. Neutral leaching was carried out at 70℃ for 2 hours. The final pH of the system was 5.03, resulting in leaching residue in zinc oxide powder and leaching solution in zinc powder containing 2.41 g / L of iron. The solid-liquid ratio of high-sulfur zinc oxide powder to waste electrolyte was 1:4.12 g:mL.

[0032] (2) A slurry is prepared by mixing zinc powder immersion solution with high-silicon zinc calcined sand. Sufficient air is then introduced to oxidize the ferrous ions in the slurry, converting them into Fe. 3+ Add a simulated low-temperature leaching solution prepared from waste electrolyte of wet zinc smelting and zinc sulfate solution (the simulated low-temperature leaching solution contains 122 g / L zinc, 0.51 g / L iron, and has a pH of 2.57). At a temperature of 70℃ and an initial pH of 2.53, slowly add the waste electrolyte of wet zinc smelting to control the pH of the slurry to 1.5-2.0 and react for 1.5 h. Slowly add high-silicon zinc calcined sand to control the pH of the slurry to 5.12 and react for 1 h to achieve zinc leaching and avoid the formation of silica gel. This yields zinc ore leaching residue and zinc ore leaching solution containing 142 g / L zinc and 0.012 g / L iron. The zinc ore leaching solution is sent to the wet zinc smelting purification process. When the zinc powder leaching solution is mixed with high-silicon zinc calcined sand, the mass ratio of high-silicon zinc calcined sand to high-sulfur zinc oxide powder in step (1) is 1:0.78.

[0033] (3) After mixing the leaching residue in zinc powder with the leaching residue in zinc ore, a simulated iron-removed solution prepared from wet zinc smelting waste electrolyte and zinc sulfate solution (the simulated iron-removed solution contains 27 g / L sulfuric acid, 113 g / L zinc, and 2.87 g / L iron) is added. Low-acid leaching is carried out at 80℃ and pH 2.5-3.5 for 2 hours to obtain low-acid leaching residue and low-acid leaching solution (low-acid leaching solution pH 2.75, 122 g / L zinc, and 0.53 g / L iron). Low-acid leaching can cause the iron in the iron-removed solution to form goethite-like precipitates that enter the low-acid leaching residue.

[0034] (4) The low-leaching residue was added to a simulated high-leaching solution prepared from the waste electrolyte of wet zinc smelting and zinc sulfate solution (the simulated high-leaching solution contained 115 g / L sulfuric acid, 52 g / L zinc, and 7.51 g / L iron). Hot acid leaching was carried out at 90℃ for 2 hours until the final pH reached 0.32. Simultaneously, oxidative leaching of sulfides and reductive leaching of zinc ferrite were performed to obtain hot-leaching residue and hot-leaching solution (the hot-leaching solution contained 35 g / L sulfuric acid, 85 g / L zinc, and 20.51 g / L iron, of which Fe...). 3+ 0.46 g / L);

[0035] (5) Add the hot acid residue to the waste electrolyte of wet zinc smelting and perform high acid leaching at 80℃ for 3 hours until the final sulfuric acid concentration reaches 113 g / L, to obtain a high-leaching solution (containing 112 g / L sulfuric acid, 55 g / L zinc, and 7.82 g / L iron, of which Fe... 3+ 1.16 g / L) and lead-silver slag (containing 4.66 wt% zinc, 15.7 wt% lead, and 252 g / t silver);

[0036] (6) Add high-sulfur zinc oxide powder (the amount of high-sulfur zinc oxide powder added is 25% of the mass of high-sulfur zinc oxide powder in step (1)) to the hot immersion solution, and neutralize and reduce it at a temperature of 85℃ and a pH value of 4.0-5.0 to obtain a neutralized solution (neutralized solution pH 4.69, zinc content 112g / L, iron content 20.73g / L, of which Fe 3+ 0.18 g / L) and neutralization residue, the neutralization residue is returned to step (4) and combined with low leaching residue for hot acid leaching;

[0037] (7) The neutralized solution was subjected to low-temperature hematite removal for 3 hours at a temperature of 160℃ and an oxygen partial pressure of 0.5MPa to obtain a hematite product with an iron content of 57.8% and a liquid after iron removal (the liquid after iron removal contained 28g / L of sulfuric acid, 113g / L of zinc and 2.67g / L of iron).

[0038] Example 2: The high-silicon zinc calcined sand, high-sulfur zinc oxide powder, and wet zinc smelting waste electrolyte in this example are the same as in Example 1;

[0039] A method for co-leaching high-silicon zinc roasted ore with high-sulfur zinc oxide powder (see...) Figure 1 The specific steps are as follows:

[0040] (1) High-sulfur zinc oxide powder was added to the waste electrolyte without the need for oxidant precipitation of iron. Neutral leaching was carried out at 80℃ for 1.5h. The final pH of the system was 5.07, resulting in leaching residue in zinc oxide powder and leaching solution in zinc powder containing 2.68g / L of iron. The solid-liquid ratio of high-sulfur zinc oxide powder to waste electrolyte was 1:4.10 (g:mL).

[0041] (2) A slurry is prepared by mixing zinc powder immersion solution with high-silicon zinc calcined sand. Sufficient air is then introduced to oxidize the ferrous ions in the slurry, converting them into Fe. 3+ Add the low-temperature leaching solution produced in Example 1, and slowly add the wet zinc smelting waste electrolyte at a temperature of 80℃ and an initial pH of 2.68 to control the slurry pH to 1.5-2.0 and react for 1 hour. Then slowly add high-silicon zinc calcined sand to control the slurry pH to 5.07 and react for 1.5 hours to achieve zinc leaching and avoid the formation of silica gel. This yields zinc ore leaching residue and zinc ore leaching solution containing 141 g / L of zinc and 0.014 g / L of iron. The zinc ore leaching solution is sent to the wet zinc smelting purification process. When the zinc powder leaching solution is mixed with high-silicon zinc calcined sand, the mass ratio of high-silicon zinc calcined sand to high-sulfur zinc oxide powder in step (1) is 1:0.8.

[0042] (3) After mixing the leaching residue in zinc powder with the leaching residue in zinc ore, the iron-removed liquid produced in Example 1 is added, and low-acid leaching is carried out at a temperature of 90℃ and pH 2.5-3.5 for 1.5h to obtain low-acid leaching residue and low-acid leaching liquid (low-acid leaching liquid pH 2.96, zinc content 119g / L, iron content 0.52g / L); low-acid leaching can cause the iron in the iron-removed liquid to form goethite-like precipitates and enter the low-acid leaching residue;

[0043] (4) The low-leaching residue was mixed with the neutralized residue produced in Example 1 and added to the high-leaching solution produced in Example 1. Hot acid leaching was carried out at 85°C for 2 hours until the final pH reached 0.41. Simultaneously, oxidative leaching of sulfides and reductive leaching of zinc ferrite were performed to obtain hot-leaching residue and hot-leaching solution (the hot-leaching solution contained 32 g / L sulfuric acid, 87 g / L zinc, and 20.36 g / L iron, of which Fe...). 3+ 0.42g / L);

[0044] (5) Add the hot acid residue to the waste electrolyte of wet zinc smelting and carry out high acid leaching at 85℃ for 2.5h until the final sulfuric acid concentration reaches 120g / L, to obtain a high leaching solution (containing 118g / L sulfuric acid, 52g / L zinc, and 7.69g / L iron, of which Fe... 3+ 1.02 g / L) and lead-silver slag (containing 4.72 wt% zinc, 15.8 wt% lead, and 266 g / t silver);

[0045] (6) Add high-sulfur zinc oxide powder (the amount of high-sulfur zinc oxide powder added is 23% of the mass of high-sulfur zinc oxide powder in step (1)) to the hot immersion solution, and neutralize and reduce it at a temperature of 80℃ and a pH value of 4.0-5.0 to obtain a neutralized solution (neutralized solution pH 4.52, zinc content 111g / L, iron content 20.98g / L, of which Fe 3+ 0.26 g / L) and neutralization residue, the neutralization residue is returned to step (4) and combined with low leaching residue for hot acid leaching;

[0046] (7) The neutralized solution was subjected to low-temperature hematite removal for 4 hours at a temperature of 150℃ and an oxygen partial pressure of 0.3MPa to obtain a hematite product with an iron content of 56.2% and a liquid after iron removal (the liquid after iron removal contained 26g / L of sulfuric acid, 112g / L of zinc and 2.95g / L of iron).

[0047] Example 3: The high-silicon zinc calcined sand, high-sulfur zinc oxide powder, and wet zinc smelting waste electrolyte in this example are the same as in Example 1;

[0048] A method for co-leaching high-silicon zinc roasted ore with high-sulfur zinc oxide powder (see...) Figure 1 The specific steps are as follows:

[0049] (1) High-sulfur zinc oxide powder was added to the waste electrolyte without the need for oxidant precipitation of iron. Neutral leaching was carried out at 75℃ for 2 hours. The final pH of the system was 4.81, resulting in leaching residue in zinc oxide powder and leaching solution in zinc powder containing 2.95 g / L of iron. The solid-liquid ratio of high-sulfur zinc oxide powder to waste electrolyte was 1:4.2 g:mL.

[0050] (2) A slurry is prepared by mixing zinc powder immersion solution with high-silicon zinc calcined sand. Sufficient air is then introduced to oxidize the ferrous ions in the slurry, converting them into Fe. 3+ Add the low-temperature leaching solution produced in Example 2, and slowly add the wet zinc smelting waste electrolyte at a temperature of 75°C and an initial pH of 2.91 to control the slurry pH to 1.5-2.0 and react for 1.5 hours. Then slowly add high-silicon zinc calcined sand to control the slurry pH to 5.16 and react for 1.5 hours to achieve zinc leaching and avoid the formation of silica gel. This yields zinc ore leaching residue and zinc ore leaching solution containing 143 g / L of zinc and 0.011 g / L of iron. The zinc ore leaching solution is sent to the wet zinc smelting purification process. When the zinc powder leaching solution is mixed with high-silicon zinc calcined sand, the mass ratio of high-silicon zinc calcined sand to high-sulfur zinc oxide powder in step (1) is 1:0.75.

[0051] (3) After mixing the leaching residue in zinc powder with the leaching residue in zinc ore, the iron-removed liquid produced in Example 2 is added, and low-acid leaching is carried out at a temperature of 85℃ and pH 2.5-3.5 for 2 hours to obtain low-acid leaching residue and low-acid leaching liquid (low-acid leaching liquid pH 2.68, zinc content 121g / L, iron content 0.55g / L); low-acid leaching can cause the iron in the iron-removed liquid to form goethite-like precipitates and enter the low-acid leaching residue;

[0052] (4) The low-leaching residue was mixed with the neutralized residue produced in Example 2 and added to the high-leaching solution produced in Example 2. Hot acid leaching was carried out at 80°C for 2.5 hours until the final pH reached 0.48. Simultaneously, oxidative leaching of sulfides and reductive leaching of zinc ferrite were performed to obtain hot-leaching residue and hot-leaching solution (the hot-leaching solution contained 30 g / L sulfuric acid, 88 g / L zinc, and 20.35 g / L iron, of which Fe...). 3+ 0.41 g / L);

[0053] (5) Add the hot acid residue to the waste electrolyte of wet zinc smelting and perform high acid leaching at 90℃ for 3 hours until the final sulfuric acid concentration reaches 102 g / L, to obtain a high-leaching solution (containing 102 g / L sulfuric acid, 61 g / L zinc, and 7.75 g / L iron, of which Fe... 3+ 1.22 g / L) and lead-silver slag (containing 4.25 wt% zinc, 16.2 wt% lead, and 295 g / t silver);

[0054] (6) Add high-sulfur zinc oxide powder (the amount of high-sulfur zinc oxide powder added is 27% of the mass of high-sulfur zinc oxide powder in step (1)) to the hot immersion solution, and neutralize and reduce it at a temperature of 90℃ and a pH value of 4.0-5.0 to obtain a neutralized solution (neutralized solution pH 4.61, zinc content 115g / L, iron content 20.65g / L, of which Fe 3+ 0.26 g / L) and neutralization residue, the neutralization residue is returned to step (4) and combined with low leaching residue for hot acid leaching;

[0055] (7) The neutralized solution was subjected to low-temperature hematite removal for 4 hours at a temperature of 155℃ and an oxygen partial pressure of 0.35MPa to obtain a hematite product with an iron content of 57.1% and a liquid after iron removal (the liquid after iron removal contained 29g / L sulfuric acid, 116g / L zinc and 2.37g / L iron).

[0056] Table 1 compares the technical indicators of traditional single leaching with those of the combined leaching in Examples 1-3.

[0057] Table 1 Technical specifications of traditional single leaching and combined leaching in Examples 1-3 As shown in Table 1, the zinc leaching rate of the combined leaching is slightly higher than that of the leaching of roasted ore alone, and the slag rate is also increased. Compared with the leaching of zinc oxide powder alone, the zinc leaching rate is significantly higher and the slag rate is significantly lower. However, the zinc leaching rate of the combined leaching is better than the average zinc leaching rate of roasted ore leaching alone and zinc oxide powder leaching alone, and the slag rate is lower than the average slag rate of roasted ore leaching alone and zinc oxide powder leaching alone. The combined leaching achieves simultaneous and efficient leaching of roasted ore and zinc oxide powder, and the zinc content in the slag is significantly lower than that of roasted ore leaching alone and zinc oxide powder leaching alone. When leaching alone, the lead content of the roasted sand leaching residue is relatively low (less than 10% of the minimum market pricing requirement), and the silver content of the zinc oxide powder leaching residue is relatively low (less than 200g / t of the minimum market pricing requirement). The silver content of the combined leaching residue is lower than that of the roasted sand leaching residue alone, while the lead content is significantly higher. The silver content of the combined leaching residue is significantly higher than that of the zinc oxide powder leaching residue alone, while the lead content remains basically unchanged. However, the lead and silver contents in the combined leaching both meet the minimum market pricing requirements, and the pricing coefficient is better than that of lead and silver in the separate leaching residues, which significantly improves the economic value of the lead-silver residue.

[0058] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for co-leaching high-silicon zinc roasted ore with high-sulfur zinc oxide powder, characterized in that, The specific steps are as follows: (1) High-sulfur zinc oxide powder is added to waste electrolyte for neutral leaching to obtain zinc oxide powder leaching residue and zinc powder leaching solution; the solid-liquid ratio of high-sulfur zinc oxide powder to waste electrolyte is 1:4~4.2 g:mL, the neutral leaching temperature is 70~80 ℃, the time is 1.5~2 h, and the final pH is 4.8~5.1; (2) The zinc powder leaching solution is mixed with high-silicon zinc calcined sand to obtain a slurry. Air is introduced to oxidize the ferrous ions in the slurry. A simulated low-leaching solution prepared by wet zinc smelting waste electrolyte and zinc sulfate solution is added. At a temperature of 70~80℃ and an initial pH of 2.5~3.0, the wet zinc smelting waste electrolyte is slowly added to control the pH of the slurry to 1.5~2.0 and react for 1~1.5h. High-silicon zinc calcined sand is slowly added to control the pH of the slurry to 5.0~5.2 and react for 1~1.5h to obtain zinc ore leaching residue and zinc ore leaching solution. The zinc ore leaching solution is sent to the wet zinc smelting purification process. The simulated low-leaching solution contains 119~122g / L of zinc, 0.51~0.55g / L of iron, and has a pH of 2.57~2.

96. (3) After the leaching residue in zinc powder is mixed with the leaching residue in zinc ore, a simulated iron removal solution prepared by wet zinc smelting waste electrolyte and zinc sulfate solution is added for low acid leaching to obtain low leaching residue and low leaching solution. The low leaching solution is returned to step (2) to replace the simulated low leaching solution. The simulated iron removal solution contains 26~29 g / L of sulfuric acid, 112~116 g / L of zinc, and 2.37~2.95 g / L of iron. (4) The low-leaching residue is added to the simulated high-leaching solution prepared by wet zinc smelting waste electrolyte and zinc sulfate solution, and hot acid leaching is carried out to obtain hot-leaching residue and hot-leaching solution; the hot acid leaching simultaneously realizes the oxidative leaching of sulfides and the reductive leaching of zinc ferrite; the simulated high-leaching solution contains 102~118 g / L of sulfuric acid, 52~61 g / L of zinc, and 7.51~7.82 g / L of iron; (5) Add the hot acid residue to the wet zinc smelting waste electrolyte for high acid leaching to obtain high leaching solution and lead-silver residue. The high leaching solution is returned to step (4) to replace the simulated high leaching solution. (6) The hot leaching liquid is neutralized and reduced by high-sulfur zinc oxide powder to obtain neutralized liquid and neutralized residue. The neutralized residue is returned to step (4) and combined with the low-sulfur leaching residue for hot acid leaching. (7) The neutralized liquid is subjected to low-temperature hematite removal for 3-4 hours at a temperature of 150-160℃ and an oxygen partial pressure of 0.3-0.5MPa to obtain hematite product and iron removal liquid. The iron removal liquid is returned to step (3) to replace the simulated iron removal liquid.

2. The method for co-leaching high-silicon zinc roasted ore and high-sulfur zinc oxide powder according to claim 1, characterized in that: Step (1) The high-sulfur zinc oxide powder contains more than 5 wt% sulfur.

3. The method for co-leaching high-silicon zinc roasted ore and high-sulfur zinc oxide powder according to claim 1, characterized in that: When mixing the zinc powder immersion solution with high-silicon zinc calcined sand in step (2), the mass ratio of high-silicon zinc calcined sand to high-sulfur zinc oxide powder in step (1) is 1:0.75~0.

80.

4. The method for co-leaching high-silicon zinc roasted ore and high-sulfur zinc oxide powder according to claim 1, characterized in that: Step (3) The low acid leaching temperature is 80~90℃, the time is 1.5~2h, and the pH of the leaching system is 2.5~3.

5.

5. The method for co-leaching high-silicon zinc roasted ore and high-sulfur zinc oxide powder according to claim 1, characterized in that: Step (4) The temperature of hot acid leaching is 80~90℃, the time is 2.0~2.5h, and the final pH is 0.3~0.

5.

6. The method for co-leaching high-silicon zinc roasted ore and high-sulfur zinc oxide powder according to claim 1, characterized in that: Step (5) The high acid leaching temperature is 80~90℃, the time is 2.5~3.0h, and the final sulfuric acid concentration is 100~120g / L.

7. The method for co-leaching high-silicon zinc roasted ore and high-sulfur zinc oxide powder according to claim 1, characterized in that: In step (6), the amount of high-sulfur zinc oxide powder added is 23-27% of the mass of the high-sulfur zinc oxide powder in step (1). The neutralization and reduction temperature is 80-90℃, the solution pH is 4.0-5.0, and the Fe content in the neutralization solution is... 3+ Less than 0.2 g / L.

8. The method for co-leaching high-silicon zinc roasted ore and high-sulfur zinc oxide powder according to claim 1, characterized in that: Step (7) After iron removal, the iron concentration in the liquid is less than 3 g / L.

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