A method for extracting germanium from lead slag by using magnetic seed separation and smoke neutralization

Abstract

The invention relates to a method for extracting germanium by using magnetic seed crystals in lead slag in coordination with neutralization of flue dust, and belongs to the technical field of germanium extraction. The invention mainly includes 8 processes of neutral leaching, high acid leaching, gradient magnetic separation, seed crystal preparation, seed crystal addition, neutralization and extraction of germanium, hydrochloric acid leaching, and distillation. Neutral leaching can effectively separate zinc, germanium and iron in flue dust, high acid leaching can effectively leach germanium and iron in flue dust, gradient magnetic separation is performed on leached slag to magnetically select magnetic substances with different saturation magnetic field strengths in lead slag, seed crystal preparation crushes and ball-mills the magnetic substances into micro-nano particles, and adds low Ms (saturation magnetic field strength) substances as seed crystals, neutralization and extraction of germanium process by adding neutralizer and oxidant to oxidize and neutralize iron to adsorb and precipitate germanium, and high Ms seed crystals are added in the late stage of neutralization to strengthen the precipitation of neutralized germanium slag, hydrochloric acid is used to leach the germanium of wet neutralized germanium slag in leaching, and chlorine is added in distillation to volatilize the leached germanium in the form of GeCl4 gas.

Description

Technical Field

[0001] The invention relates to a method for extracting germanium from lead slag by magnetically separating crystal seeds in coordination with smoke and dust neutralization, belonging to the technical field of germanium extraction. Background Art

[0002] Germanium is an important raw material for optical fiber preforms and solar cells, and its demand is growing worldwide. Germanium mainly comes from germanium-containing zinc oxide smoke, and the mainstream process includes the "two-stage countercurrent leaching-germanium precipitation-roasting-chlorination distillation" process. Among them, the cost of the tannin germanium precipitation process accounts for more than 80% of the entire process cost. Tannic acid with a mass of 30 times that of germanium is required to enrich and extract germanium from a milligram germanium solution to form a tannin germanium slag with a germanium content of 3-5%. The tannin germanium slag is then roasted to obtain a germanium concentrate with a germanium content of ~25%. Direct roasting of tannin germanium slag will not only waste a lot of organic resources, but also produce a lot of CO 2 .

[0003] Patent CN201911126152.5 applied for a method for recovering germanium dioxide from germanium-containing smoke. After the germanium-containing smoke is leached by a two-stage alkaline method, the germanium dioxide is recovered by filtration, purification, and precipitation. The germanium recovery rate is higher than 90%, and the cost is greatly reduced. Patent CN202310187035.X applied for a method for efficiently enriching germanium by pre-zinc removal and neutralization of germanium-containing zinc oxide smoke, which mainly includes neutral leaching, one-stage leaching, and two-stage leaching. The five steps of leaching, neutralization and precipitation of germanium, and recycling of the neutralized liquid can achieve a Ge enrichment rate of 95.83%, and the Ge grade in the germanium-rich material can reach 3.53%; Patent 202310357879.4 applies for a method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching liquid, first adding a reducing agent for reduction, then adding a neutralizing agent for neutralization to obtain a neutralized germanium slag, and then leaching the neutralized germanium slag with sulfuric acid to obtain a germanium-rich leaching liquid, and the germanium concentration in the germanium-rich leaching liquid is enriched by 10 to 20 times. And it can avoid the adverse effects of organic matter on the zinc electrolysis process. Patent CN202310378031.X is a method for preparing germanium concentrate from zinc-germanium leachate by neutralization precipitation. Zinc oxide smoke is added to the zinc-germanium leachate, and liquid-solid separation is performed to obtain pre-neutralized liquid and pre-neutralized slag. Neutralizer A is added to the pre-neutralized liquid to react for a period of time, and an ultrasonic cavitation generator is introduced. Neutralizer B is added, and liquid-solid separation is performed to obtain neutralized liquid and neutralized germanium slag. The neutralized germanium slag is washed with water and dried to obtain germanium concentrate. The above processes all use neutralization and precipitation of germanium to extract germanium resources, mainly by generating iron hydroxide colloid in the germanium-containing leachate to adsorb and precipitate germanium. When precipitating germanium, the iron hydroxide colloid will simultaneously adsorb impurities such as zinc, iron, and silicon, resulting in a low germanium content in the neutralized germanium slag, and a large amount of waste residue and waste liquid in the subsequent chlorination distillation. Summary of the invention

[0004] Aiming at the problems of low germanium content in the neutralized germanium slag in the existing neutralization and germanium precipitation process, large amount of waste slag and waste liquid in the subsequent chlorination distillation, the present invention proposes a method for neutralizing and extracting germanium in lead slag by using magnetic separation seeds in coordination with flue dust, which mainly includes 8 steps of neutral leaching, high acid leaching, gradient magnetic separation, seed preparation, seed addition, neutralization and extraction of germanium, hydrochloric acid leaching and distillation. Neutral leaching can effectively separate zinc, germanium and iron in the flue dust, high acid leaching can effectively leach germanium and iron in the flue dust, gradient magnetic separation is performed on the leached slag to magnetically select magnetic substances with different saturation magnetic field strengths in the lead slag, seed preparation crushes and ball-mills the magnetic substances into micro-nano particles, and low Ms (saturation magnetic field strength) substances are added as initial germanium precipitation seeds, neutralization and extraction of germanium by adding neutralizers and oxidants to oxidize iron to neutralize and adsorb and precipitate germanium, and high Ms seeds are added in the late stage of neutralization to strengthen the precipitation of neutralized germanium slag, and then hydrochloric acid is used to leach the germanium in the wet neutralized germanium slag, and chlorine is added in the distillation to leached germanium in the form of GeCl 4 The present invention uses the magnetic material in the lead slag to neutralize the seed crystal in the germanium precipitation, and can reduce the zinc loss of the lead slag while reducing the encapsulation and adsorption of the leaching solution by the colloidal iron in the neutralization and germanium precipitation stage, thereby reducing the zinc neutralization loss and increasing the germanium content of the neutralization slag. The germanium content in the neutralization germanium slag reaches 27.13%, thereby reducing the consumption of hydrochloric acid and chlorine in the leaching stage and the distillation stage, effectively reducing the distillation residue and residual liquid, and the germanium recovery rate reaches 93.36%.

[0005] A method for extracting germanium from lead slag by magnetically selecting crystal seeds in coordination with smoke neutralization, the specific steps are as follows:

[0006] (1) Neutral leaching: adding smoke to waste electrolyte for neutral leaching, and obtaining neutral leaching solution and neutral leaching residue by liquid-solid separation;

[0007] (2) High acid leaching: The neutral leaching residue is added to a mixed acid solution of sulfuric acid and waste electrolyte for high acid leaching, and high acid leaching solution I and high zinc-lead slag slurry are obtained by dense separation;

[0008] (3) Gradient magnetic separation: Gradient magnetic separation is performed on the high zinc lead slag slurry to select high Ms material, low Ms material and residual low zinc lead slag slurry respectively, and the low zinc lead slag slurry is liquid-solid separated to obtain high acid leaching solution II and low zinc lead slag;

[0009] (4) Seed preparation: high Ms material and low Ms material are respectively prepared by ball milling to obtain high Ms seed crystals and low Ms seed crystals;

[0010] (5) Seed addition: adding low-Ms seed crystals to the mixture of high-acid leaching solution I and high-acid leaching solution II to obtain seed crystal-high-acid leaching solution;

[0011] (6) Neutralization and germanium extraction: Add an oxidant and a neutralizer to the seed-high acid leaching solution to neutralize and extract germanium I, then add a high Ms seed to neutralize and extract germanium II, and separate the liquid and solid to obtain the neutralized liquid and neutralized germanium slag;

[0012] (7) Leaching: adding the neutralized germanium slag into hydrochloric acid for leaching to obtain leached slurry;

[0013] (8) Distillation: Chlorine gas is introduced into the leached slurry and distillation is performed to obtain germanium tetrachloride and residual liquid. A neutralizing agent is added to the residual liquid for neutralization, and the liquid-solid separation is performed to obtain distillation residue and distillation residual liquid.

[0014] In terms of mass percentage, the germanium content in the smoke of step (1) is 382-2998 g / t, the zinc content is 45.56-67.88%, the lead content is 6.13-17.94%, the iron content is 0.97-2.49%, and the silicon dioxide content is 1.53-3.70%; the zinc content in the waste electrolyte is 20-60 g / L, and the acidity is 100-160 g / L.

[0015] Preferably, in the step (1), the leaching liquid-to-solid ratio of the waste electrolyte to the smoke is 3:1-6:1, the leaching temperature is 50-70°C, the leaching time is 15-40 min, the germanium content in the neutral leaching solution is 1.27-5.00 mg / L, the zinc content is 135.87-164.76 g / L, the iron content is 0.058-0.30 g / L, the lead content is 30-70 mg / L, the silicon dioxide content is 100-150 mg / L, and the leaching endpoint pH is 2-4; in terms of mass percentage, the germanium content in the neutral leaching residue is 834.75-14349.47 g / t, the zinc content is 20.32-24.47%, the iron content is 4.52-6.10%, the lead content is 29.64-39.60%, and the silicon dioxide content is 7.40-9.02%.

[0016] Preferably, the acidity of the mixed acid solution in step (2) is 60.63-79.77 g / L, the leaching liquid-solid ratio of the mixed acid solution to the neutral leaching residue is 5:1-8:1 in mL:g, the leaching temperature is 65-95°C, and the leaching time is 60-120 min.

[0017] Preferably, in step (3), the first gradient magnetic field strength is 0.2-0.8T, the second gradient magnetic field strength is 1.5-2T, the first gradient magnetic separation obtains high Ms material, and the second gradient magnetic separation obtains low Ms material; in terms of mass percentage, the iron content of the high Ms material is 30-45%, and the zinc content is 22-32%; in terms of mass percentage, the iron content of the low Ms material is 35-50%, and the zinc content is 25-35%; in terms of mass percentage, the germanium content of the low zinc lead slag leaching residue is 49.31-910.74 g / t, the zinc content is 14.71-18.57%, the iron content is 2.54-3.30%, the lead content is 31.04-38.59%, and the silicon dioxide content is 6.48-23.90%.

[0018] Preferably, in the mixed solution after mixing the high acid leaching solution I and the high acid leaching solution II in step (5), the germanium content is 156.83-1684.98 mg / L, the zinc content is 28.81-58.34 g / L, the iron content is 2.61-4.90 g / L, the lead content is 50-90 mg / L, the silicon dioxide content is 120-200 mg / L, the acidity is 20-50 g / L, and the addition amount of the low Ms seed crystal is 0.5-1 g / L.

[0019] Preferably, in step (6), the oxidant is air, oxygen, hydrogen peroxide, ozone, potassium permanganate or manganese dioxide, and the neutralizer is ammonia water, sodium hydroxide, calcium hydroxide, zinc oxide or sodium carbonate; the neutralization temperature of neutralization and germanium extraction I is 45-70°C, the neutralization pH is 4.5-5.5, and the neutralization time is 30-60 min; the amount of high Ms seed crystals added is lower than the amount of low Ms seed crystals added in step (5), the amount of high Ms seed crystals added is 0.3-0.8 g / L, the neutralization temperature of neutralization and germanium extraction II is 45-70°C, the neutralization pH is 4.5-5.5, and the neutralization time is 30-60 min.

[0020] Preferably, after the neutralization in step (6), the germanium content in the liquid is 0.31-3.37 mg / L, the zinc content is 28.78-58.29 g / L, the iron content is 13.08-24.52 mg / L, the lead content is 0.25-0.45 mg / L, and the silicon dioxide content is 0.60-1.00 mg / L; in terms of mass percentage, the germanium content in the neutralized germanium slag is 1.86-27.13%, the zinc content is 0.32-0.89%, the iron content is 39.85-55.15%, the lead content is 0.56-0.76%, and the silicon dioxide content is 1.36-1.84%.

[0021] Preferably, in step (7), the concentration of hydrochloric acid is 5-8 mol / L, the liquid-solid ratio of hydrochloric acid to neutralized germanium slag is 4:1-8:1, and the leaching time is 60-120 min.

[0022] Preferably, in step (8), the chlorine gas introduction rate is 90-130 g / h, the distillation temperature is 90-110°C, and the distillation time is 2-6 h; the neutralizing agent is calcium oxide, calcium hydroxide or calcium carbonate, the neutralization temperature is 50-70°C, and the neutralization time is 20-40 min; the germanium content in the distillation residue is 4.42-32.19 mg / L, the zinc content is 0.10-1.10 g / L, and the iron content is 49. The content of germanium in the distillation residue is 0.11~2.15%, the content of zinc is 0.20~0.75%, the content of iron is 16.83~17.31%, the content of lead is 5.09~6.43%, and the content of silicon dioxide is 10.96~15.52% in terms of mass percentage.

[0023] The beneficial effects of the present invention are:

[0024] (1) The present invention realizes differential enrichment of zinc and germanium through neutral leaching + high acid leaching, which has higher germanium enrichment efficiency than the existing two-stage leaching;

[0025] (2) The gradient magnetic separation after high acid leaching in the present invention can select materials with different saturation magnetic field strengths, reduce the zinc content of the slag, and the selected magnetic materials can be used as neutralization and precipitation germanium seeds to achieve high-value utilization of difficult-to-leach zinc phases;

[0026] (3) The present invention adds magnetic seed crystals during the neutralization and precipitation of germanium to reduce the surface nucleation energy, promote the hydrolysis of iron ions to precipitate and adsorb germanium, increase the density of precipitated particles, and reduce the adsorption of other metals by the precipitated colloid. The germanium content in the neutralized germanium slag reaches 27.13%;

[0027] (4) The present invention can effectively solve the problems of low germanium content in the germanium slag in the current reported neutralization germanium precipitation process, large amount of waste slag and waste liquid in the subsequent chlorination distillation, and the recovery rate of germanium reaches 93.36%. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with specific implementation modes, but the protection scope of the present invention is not limited to the described contents.

[0030] Example 1: The main components of zinc oxide smoke in this example are shown in Table 1;

[0031] Table 1 Main components of zinc oxide dust (wt. %)

[0032] Ge* Zn Pb Fe <![CDATA[SiO 2 ]]> 382 45.56 17.94 2.49 3.70

[0033] As shown in Table 1, in terms of mass percentage, the germanium content in the smoke of this embodiment is 382 g / t, the zinc content is 45.56%, the lead content is 17.94%, the iron content is 2.49%, and the silicon dioxide content is 3.70%;

[0034] A method for extracting germanium from lead slag by magnetic separation of crystal seeds and coordinated flue gas neutralization (see Figure 1 ), the specific steps are as follows:

[0035] (1) Neutral leaching: adding smoke to waste electrolyte for neutral leaching, and performing liquid-solid separation to obtain neutral leaching solution and neutral leaching residue; the waste electrolyte has a zinc content of 20 g / L and an acidity of 100 g / L; the leaching liquid-solid ratio of the waste electrolyte to smoke is 3:1, the leaching temperature is 50°C, the leaching time is 15 min, the germanium content in the neutral leaching solution is 1.27 mg / L, the zinc content is 135.87 g / L, the iron content is 0.30 g / L, the lead content is 70 mg / L, the silicon dioxide content is 150 mg / L, and the leaching endpoint pH is 2; in terms of mass percentage, the germanium content in the neutral leaching residue is 834.75 g / t, the zinc content is 23.23%, the iron content is 5.30%, the lead content is 39.60%, and the silicon dioxide content is 8.17%;

[0036] (2) High acid leaching: the neutral leaching residue is added to a mixed acid solution of sulfuric acid and waste electrolyte for high acid leaching, and concentrated separation is performed to obtain a high acid leaching solution I and a high zinc-lead slag slurry; the acidity of the mixed acid solution is 60.63 g / L, the leaching liquid-solid ratio of the mixed acid solution to the neutral leaching residue is 5:1 in mL:g, the leaching temperature is 65°C, and the leaching time is 60 min;

[0037] (3) Gradient magnetic separation: gradient magnetic separation is performed on the high zinc lead slag slurry to select high Ms material, low Ms material and residual low zinc lead slag slurry respectively, and the low zinc lead slag slurry is separated into high acid leaching solution II and low zinc lead slag by liquid-solid separation; the first gradient magnetic field strength is 0.8T, the second gradient magnetic field strength is 2T, the first gradient magnetic separation obtains high Ms material, and the second gradient magnetic separation obtains low Ms material; in terms of mass percentage, the iron content of the high Ms material is 30%, and the zinc content is 22%; in terms of mass percentage, the iron content of the low Ms material is 35%, and the zinc content is 25%; in terms of mass percentage, the germanium content of the low zinc lead slag leaching slag is 49.31g / t, the zinc content is 18.57%, the iron content is 2.77%, the lead content is 38.59%, and the silicon dioxide content is 14.03%;

[0038] (4) Seed preparation: High Ms material and low Ms material were respectively added with water (dispersant) and ball-milled for 2 h to obtain high Ms seed crystals and low Ms seed crystals;

[0039] (5) Seed addition: adding low Ms seed crystals to the mixture of high acid leaching solution I and high acid leaching solution II to obtain seed crystal-high acid leaching solution; the mixture of high acid leaching solution I and high acid leaching solution II has a germanium content of 156.83 mg / L, a zinc content of 28.81 g / L, an iron content of 4.90 g / L, a lead content of 90 mg / L, a silicon dioxide content of 200 mg / L, an acidity of 20 g / L, and an addition amount of low Ms seed crystals of 1 g / L;

[0040] (6) Neutralization and extraction of germanium: Add an oxidant (air) and a neutralizer (ammonia water) to the seed-high acid leaching solution to neutralize and extract germanium I. The neutralization temperature of neutralization and extraction of germanium I is 45°C, the neutralization pH is 4.5, and the neutralization time is 30 minutes. Then add high Ms seed crystals to neutralize and extract germanium II. The addition amount of the high Ms seed crystals is 0.8 g / L. The neutralization temperature of neutralization and extraction of germanium II is 45°C, the neutralization pH is 4.5, and the neutralization time is 30 minutes. The liquid-solid separation Neutralized liquid and neutralized germanium slag are obtained; the neutralized liquid has a germanium content of 0.31 mg / L, a zinc content of 28.78 g / L, an iron content of 24.52 mg / L, a lead content of 0.45 mg / L, and a silicon dioxide content of 1.00 mg / L; in terms of mass percentage, the neutralized germanium slag has a germanium content of 1.86%, a zinc content of 0.32%, an iron content of 55.15%, a lead content of 1.01%, and a silicon dioxide content of 2.26%;

[0041] (7) Leaching: adding the neutralized germanium slag into hydrochloric acid for leaching to obtain a leached slurry; the hydrochloric acid concentration is 5 mol / L, the liquid-solid ratio of hydrochloric acid to the neutralized germanium slag is 4:1 in mL:g, and the leaching time is 60 min;

[0042] (8) Distillation: Chlorine gas is introduced into the leached slurry and distilled to obtain germanium tetrachloride and residual liquid, a neutralizing agent is added to the residual liquid for neutralization, and liquid-solid separation is performed to obtain distillation residue and distillation residue; the chlorine gas introduction rate is 90 g / h, the distillation temperature is 90°C, and the distillation time is 2 h; the neutralizing agent is calcium oxide, the neutralization temperature is 50°C, and the neutralization time is 20 min; the germanium content in the distillation residue is 4.42 mg / L, the zinc content is 0.81 g / L, the iron content is 137.18 g / L, the lead content is 2.28 g / L, and the silicon dioxide content is 5.09 g / L; in terms of mass percentage, the germanium content in the distillation residue is 0.11%, the zinc content is 0.20%, the iron content is 17.31%, the lead content is 6.35%, and the silicon dioxide content is 14.19%;

[0043] The recovery rate of germanium in this embodiment is 90.62%.

[0044] Example 2: The main components of zinc oxide smoke in this example are shown in Table 2;

[0045] Table 2 Main components of zinc oxide dust (wt. %)

[0046] Ge* Zn Pb Fe <![CDATA[SiO 2 ]]> 1591 55.79 10.34 1.74 2.48

[0047] As shown in Table 2, in terms of mass percentage, the germanium content in the smoke of this embodiment is 1591 g / t, the zinc content is 59.79%, the lead content is 10.34%, the iron content is 1.74%, and the silicon dioxide content is 2.48%;

[0048] A method for extracting germanium from lead slag by magnetic separation of crystal seeds and coordinated flue gas neutralization (see Figure 1 ), the specific steps are as follows:

[0049] (1) Neutral leaching: adding smoke to waste electrolyte for neutral leaching, and performing liquid-solid separation to obtain neutral leaching solution and neutral leaching residue; the waste electrolyte has a zinc content of 46.66 g / L and an acidity of 123 g / L; the leaching liquid-solid ratio of the waste electrolyte to smoke is 5:1, the leaching temperature is 60°C, the leaching time is 30 min, the germanium content in the neutral leaching solution is 3.18 mg / L, the zinc content is 146.27 g / L, the iron content is 0.13 g / L, the lead content is 50 mg / L, the silicon dioxide content is 120 mg / L, and the leaching endpoint pH is 3; in terms of mass percentage, the germanium content in the neutral leaching residue is 5731.30 g / t, the zinc content is 20.32%, the iron content is 6.10%, the lead content is 37.62%, and the silicon dioxide content is 9.02%;

[0050] (2) High acid leaching: the neutral leaching residue is added to a mixed acid solution of sulfuric acid and waste electrolyte for high acid leaching, and concentrated separation is performed to obtain a high acid leaching solution I and a high zinc-lead slag slurry; the acidity of the mixed acid solution is 73.72 g / L, the leaching liquid-solid ratio of the mixed acid solution to the neutral leaching residue is 6:1 in mL:g, the leaching temperature is 85°C, and the leaching time is 90 min;

[0051] (3) Gradient magnetic separation: gradient magnetic separation is performed on the high zinc lead slag slurry to select high Ms material, low Ms material and residual low zinc lead slag slurry respectively, and the low zinc lead slag slurry is subjected to liquid-solid separation to obtain high acid leaching solution II and low zinc lead slag; the first gradient magnetic field strength is 0.5T, and the second gradient magnetic field strength is 1.7T. The first gradient magnetic separation obtains high Ms material, and the second gradient magnetic separation obtains low Ms material; in terms of mass percentage, the iron content of the high Ms material is 35%, and the zinc content is 26%; in terms of mass percentage, the iron content of the low Ms material is 40%, and the zinc content is 30%; in terms of mass percentage, the germanium content of the low zinc lead slag leaching slag is 349.96g / t, the zinc content is 14.71%, the iron content is 3.30%, the lead content is 37.91%, and the silicon dioxide content is 23.90%;

[0052] (4) Seed preparation: High Ms material and low Ms material were respectively added with ethanol (dispersant) and ball milled for 4 h to obtain high Ms seed crystals and low Ms seed crystals;

[0053] (5) Seed addition: adding low Ms seed crystals to the mixture of high acid leaching solution I and high acid leaching solution II to obtain seed crystal-high acid leaching solution; the mixture of high acid leaching solution I and high acid leaching solution II has a germanium content of 897.32 mg / L, a zinc content of 57.56 g / L, an iron content of 4.70 g / L, a lead content of 70 mg / L, a silicon dioxide content of 150 mg / L, and an acidity of 35 g / L, and the amount of low Ms seed crystals added is 0.6 g / L;

[0054] (6) Neutralization and extraction of germanium: Add an oxidant (oxygen) and a neutralizer (sodium hydroxide) to the seed-high acid leaching solution to neutralize and extract germanium I. The neutralization temperature of neutralization and extraction of germanium I is 60°C, the neutralization pH is 5.0, and the neutralization time is 45 minutes. Then add high Ms seed crystals to neutralize and extract germanium II. The addition amount of the high Ms seed crystals is 0.5 g / L. The neutralization temperature of neutralization and extraction of germanium II is 60°C, the neutralization pH is 5.0, and the neutralization time is 45 minutes. The neutralized liquid and the neutralized germanium slag are separated; the germanium content in the neutralized liquid is 1.79 mg / L, the zinc content is 57.50 g / L, the iron content is 23.54 mg / L, the lead content is 0.35 mg / L, and the silicon dioxide content is 0.75 mg / L; in terms of mass percentage, the germanium content in the neutralized germanium slag is 9.90%, the zinc content is 0.60%, the iron content is 49.16%, the lead content is 0.73%, and the silicon dioxide content is 1.57%;

[0055] (7) Leaching: adding the neutralized germanium slag into hydrochloric acid for leaching to obtain a leached slurry; the hydrochloric acid concentration is 7 mol / L, the liquid-solid ratio of hydrochloric acid to the neutralized germanium slag is 6:1 mL:g, and the leaching time is 90 min;

[0056] (8) Distillation: Chlorine gas is introduced into the leached slurry and distilled to obtain germanium tetrachloride and residual liquid, a neutralizing agent is added to the residual liquid for neutralization, and liquid-solid separation is performed to obtain distillation residue and distillation residue; the chlorine gas introduction rate is 110 g / h, the distillation temperature is 95°C, and the distillation time is 4 hours; the neutralizing agent is calcium hydroxide, the neutralization temperature is 60°C, and the neutralization time is 30 minutes; the distillation residue contains germanium 15.66 mg / L, zinc 0.10 g / L, iron 81.53 g / L, lead 1.10 g / L, and silicon dioxide 2.36 g / L; in terms of mass percentage, the germanium content of the distillation residue is 0.65%, zinc 0.42%, iron 17.11%, lead 5.09%, and silicon dioxide 10.96%;

[0057] The recovery rate of germanium in this embodiment is 91.99%.

[0058] Example 3: The main components of zinc oxide smoke in this example are shown in Table 3;

[0059] Table 3 Main components of zinc oxide dust (wt. %)

[0060] Ge* Zn Pb Fe <![CDATA[SiO 2 ]]> 2998 67.88 6.13 0.97 1.53

[0061] As shown in Table 3, in terms of mass percentage, the germanium content in the smoke of this embodiment is 2998 g / t, the zinc content is 67.88%, the lead content is 6.13%, the iron content is 0.97%, and the silicon dioxide content is 1.53%;

[0062] A method for extracting germanium from lead slag by magnetic separation of crystal seeds and coordinated flue gas neutralization (see Figure 1 ), the specific steps are as follows:

[0063] (1) Neutral leaching: adding smoke to waste electrolyte for neutral leaching, and performing liquid-solid separation to obtain neutral leaching solution and neutral leaching residue; the waste electrolyte has a zinc content of 60 g / L and an acidity of 160 g / L; the leaching liquid-solid ratio of the waste electrolyte to smoke is 6:1, the leaching temperature is 70°C, the leaching time is 40 min, the germanium content in the neutral leaching solution is 5.00 mg / L, the zinc content is 164.76 g / L, the iron content is 0.058 g / L, the lead content is 30 mg / L, the silicon dioxide content is 100 mg / L, and the leaching endpoint pH is 4; in terms of mass percentage, the germanium content in the neutral leaching residue is 14349.47 g / t, the zinc content is 24.47%, the iron content is 4.52%, the lead content is 29.64%, and the silicon dioxide content is 7.40%;

[0064] (2) High acid leaching: the neutral leaching residue is added to a mixed acid solution of sulfuric acid and waste electrolyte for high acid leaching, and concentrated separation is performed to obtain a high acid leaching solution I and a high zinc-lead slag slurry; the acidity of the mixed acid solution is 79.77 g / L, the leaching liquid-solid ratio of the mixed acid solution to the neutral leaching residue is 8:1 in mL:g, the leaching temperature is 95°C, and the leaching time is 120 min;

[0065] (3) Gradient magnetic separation: gradient magnetic separation is performed on the high zinc-lead slag slurry to select high Ms material, low Ms material and residual low zinc-lead slag slurry respectively, and the low zinc-lead slag slurry is subjected to liquid-solid separation to obtain high acid leaching solution II and low zinc-lead slag; the first gradient magnetic field strength is 0.2T, and the second gradient magnetic field strength is 1.5T. The first gradient magnetic separation obtains high Ms material, and the second gradient magnetic separation obtains low Ms material; in terms of mass percentage, the iron content of the high Ms material is 45%, and the zinc content is 32%; in terms of mass percentage, the iron content of the low Ms material is 50%, and the zinc content is 35%; in terms of mass percentage, the germanium content of the low zinc-lead slag leaching slag is 910.74g / t, the zinc content is 16.84%, the iron content is 2.54%, the lead content is 31.04%, and the silicon dioxide content is 6.48%;

[0066] (4) Seed preparation: High Ms material and low Ms material were respectively added with ethylene glycol (dispersant) and ball milled for 6 h to obtain high Ms seed crystals and low Ms seed crystals;

[0067] (5) Seed addition: adding low Ms seed crystals to the mixture of high acid leaching solution I and high acid leaching solution II to obtain seed crystal-high acid leaching solution; the mixture of high acid leaching solution I and high acid leaching solution II has a germanium content of 1684.98 mg / L, a zinc content of 58.34 g / L, an iron content of 2.61 g / L, a lead content of 50 mg / L, a silicon dioxide content of 120 mg / L, and an acidity of 50 g / L, and the amount of low Ms seed crystals added is 0.5 g / L;

[0068] (6) Neutralization and extraction of germanium: Add an oxidant (air) and a neutralizer (ammonia water) to the seed-high acid leaching solution to carry out neutralization and extraction of germanium I. The neutralization temperature of neutralization and extraction of germanium I is 70°C, the neutralization pH is 5.5, and the neutralization time is 60 min. Then add high Ms seed crystals to carry out neutralization and extraction of germanium II. The addition amount of the high Ms seed crystals is 0.3 g / L. The neutralization temperature of neutralization and extraction of germanium II is 70°C, the neutralization pH is 5.5, and the neutralization time is 60 min. The liquid-solid separation is 1:1. Neutralized liquid and neutralized germanium slag are obtained; the germanium content in the neutralized liquid is 3.37 mg / L, the zinc content is 58.29 g / L, the iron content is 13.08 mg / L, the lead content is 0.25 mg / L, and the silicon dioxide content is 0.60 mg / L; in terms of mass percentage, the germanium content in the neutralized germanium slag is 27.13%, the zinc content is 0.89%, the iron content is 39.85%, the lead content is 0.76%, and the silicon dioxide content is 1.84%;

[0069] (7) Leaching: adding the neutralized germanium slag into hydrochloric acid for leaching to obtain a leached slurry; the hydrochloric acid concentration is 8 mol / L, the liquid-solid ratio of hydrochloric acid to the neutralized germanium slag is 8:1 mL:g, and the leaching time is 120 min;

[0070] (8) Distillation: Chlorine is introduced into the leached slurry and distilled to obtain germanium tetrachloride and residual liquid, a neutralizing agent is added to the residual liquid for neutralization, and liquid-solid separation is performed to obtain distillation residue and distillation residue; the chlorine introduction rate is 130 g / h, the distillation temperature is 110°C, and the distillation time is 6 hours; the neutralizing agent is calcium carbonate, the neutralization temperature is 70°C, and the neutralization time is 40 minutes; the germanium content in the distillation residue is 32.19 mg / L, the zinc content is 1.10 g / L, the iron content is 49.56 g / L, the lead content is 0.82 g / L, and the silicon dioxide content is 1.98 g / L; in terms of mass percentage, the germanium content in the distillation residue is 2.15%, the zinc content is 0.75%, the iron content is 16.83%, the lead content is 6.43%, and the silicon dioxide content is 15.52%;

[0071] The recovery rate of germanium in this embodiment is 93.36%.

[0072] The specific implementation modes of the present invention are described in detail above, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for extracting germanium from lead slag by using magnetically separated crystal seeds in coordination with smoke neutralization, characterized in that: The specific steps are as follows: (1) Neutral leaching: Adding germanium-containing zinc oxide dust into the waste electrolyte for neutral leaching, and performing liquid-solid separation to obtain neutral leaching solution and neutral leaching residue; (2) High acid leaching: The neutral leaching residue is added to a mixed acid solution of sulfuric acid and waste electrolyte for high acid leaching, and high acid leaching solution I and high zinc-lead slag slurry are obtained by dense separation; (3) Gradient magnetic separation: Gradient magnetic separation is performed on the high zinc lead slag slurry to select high Ms material, low Ms material and residual low zinc lead slag slurry respectively, and the low zinc lead slag slurry is liquid-solid separated to obtain high acid leaching solution II and low zinc lead slag; The first gradient magnetic field strength is 0.2~0.8T, the second gradient magnetic field strength is 1.5~2T, the first gradient magnetic separation obtains high Ms material, and the second gradient magnetic separation obtains low Ms material; (4) Seed preparation: high Ms material and low Ms material are respectively prepared by ball milling to obtain high Ms seed crystals and low Ms seed crystals; (5) Seed addition: adding low-Ms seed crystals to the mixture of high-acid leaching solution I and high-acid leaching solution II to obtain seed crystal-high-acid leaching solution; (6) Neutralization and germanium extraction: Add an oxidant and a neutralizer to the seed-high acid leaching solution to neutralize and extract germanium I, then add a high Ms seed to neutralize and extract germanium II, and separate the liquid and solid to obtain the neutralized liquid and neutralized germanium slag; (7) Leaching: adding the neutralized germanium slag into hydrochloric acid for leaching to obtain leached slurry; (8) Distillation: Chlorine gas is introduced into the leached slurry and distillation is performed to obtain germanium tetrachloride and residual liquid. A neutralizing agent is added to the residual liquid for neutralization, and the liquid-solid separation is performed to obtain distillation residue and distillation residual liquid.

2. The method for extracting germanium from lead slag by magnetic separation of crystal seeds in coordination with smoke neutralization according to claim 1, characterized in that: In terms of mass percentage, the germanium content in the smoke from step (1) is 382-2998 g / t, the zinc content is 45.56-67.88%, the lead content is 6.13-17.94%, the iron content is 0.97-2.49%, and the silicon dioxide content is 1.53-3.70%; the zinc content in the waste electrolyte is 20-60 g / L, and the acidity is 100-160 g / L.

3. The method for extracting germanium from lead slag by using magnetically separated crystal seeds in coordination with smoke neutralization according to claim 1 or 2, characterized in that: In step (1), the leaching liquid-solid ratio of the waste electrolyte to the smoke is 3:1-6:1, the leaching temperature is 50-70°C, the leaching time is 15-40 min, the germanium content in the neutral leaching solution is 1.27-5.00 mg / L, the zinc content is 135.87-164.76 g / L, the iron content is 0.058-0.30 g / L, the lead content is 30-70 mg / L, the silicon dioxide content is 100-150 mg / L, and the leaching endpoint pH is 2-4; in terms of mass percentage, the germanium content in the neutral leaching residue is 834.75-14349.47 g / t, the zinc content is 20.32-24.47%, the iron content is 4.52-6.10%, the lead content is 29.64-39.60%, and the silicon dioxide content is 7.40-9.02%.

4. The method for extracting germanium from lead slag by using magnetically separated crystal seeds in coordination with smoke neutralization according to claim 1, characterized in that: The acidity of the mixed acid solution in step (2) is 60.63-79.77 g / L, the leaching liquid-solid ratio of the mixed acid solution to the neutral leaching residue is 5:1-8:1 in mL:g, the leaching temperature is 65-95°C, and the leaching time is 60-120 min.

5. The method for extracting germanium from lead slag by using magnetic seed separation in coordination with flue dust neutralization according to claim 1, characterized in that: In step (3), the high Ms material has an iron content of 30-45% and a zinc content of 22-32% by mass; the low Ms material has an iron content of 35-50% and a zinc content of 25-35% by mass; the low zinc lead slag has a germanium content of 49.31-910.74 g / t, a zinc content of 14.71-18.57%, an iron content of 2.54-3.30%, a lead content of 31.04-38.59%, and a silicon dioxide content of 6.48-23.90% by mass.

6. The method for extracting germanium from lead slag by using magnetic seed separation in coordination with flue dust neutralization according to claim 1, characterized in that: The mixed solution after mixing the high acid leaching solution I and the high acid leaching solution II in step (5) has a germanium content of 156.83-1684.98 mg / L, a zinc content of 28.81-58.34 g / L, an iron content of 2.61-4.90 g / L, a lead content of 50-90 mg / L, a silicon dioxide content of 120-200 mg / L, an acidity of 20-50 g / L, and an added amount of low Ms seed crystals of 0.5-1 g / L.

7. The method for extracting germanium from lead slag by using magnetically separated crystal seeds in coordination with dust neutralization according to claim 1, characterized in that: In step (6), the oxidant is air, oxygen, hydrogen peroxide, ozone, potassium permanganate or manganese dioxide, and the neutralizer is ammonia water, sodium hydroxide, calcium hydroxide, zinc oxide or sodium carbonate; the neutralization temperature of neutralization and extraction of germanium I is 45-70°C, the neutralization pH is 4.5-5.5, and the neutralization time is 30-60 min; the amount of high Ms seed crystal added is lower than the amount of low Ms seed crystal added in step (5), the amount of high Ms seed crystal added is 0.3-0.8 g / L, the neutralization temperature of neutralization and extraction of germanium II is 45-70°C, the neutralization pH is 4.5-5.5, and the neutralization time is 30-60 min.

8. The method for extracting germanium from lead slag by using magnetically separated crystal seeds in coordination with smoke neutralization according to claim 1 or 7, characterized in that: After the neutralization in step (6), the germanium content in the liquid is 0.31-3.37 mg / L, the zinc content is 28.78-58.29 g / L, the iron content is 13.08-24.52 mg / L, the lead content is 0.25-0.45 mg / L, and the silicon dioxide content is 0.60-1.00 mg / L; in terms of mass percentage, the germanium content in the neutralized germanium slag is 1.86-27.13%, the zinc content is 0.32-0.89%, the iron content is 39.85-55.15%, the lead content is 0.56-0.76%, and the silicon dioxide content is 1.36-1.84%.

9. The method for extracting germanium from lead slag by using magnetic seed separation in coordination with flue dust neutralization according to claim 1, characterized in that: In step (7), the concentration of hydrochloric acid is 5-8 mol / L, the liquid-solid ratio of hydrochloric acid to neutralized germanium slag is 4:1-8:1, and the leaching time is 60-120 min.

10. The method for extracting germanium from lead slag by using magnetic seed separation in coordination with flue dust neutralization according to claim 1, characterized in that: In step (8), the chlorine gas introduction rate is 90-130 g / h, the distillation temperature is 90-110°C, and the distillation time is 2-6 h; the neutralizing agent is calcium oxide, calcium hydroxide or calcium carbonate, the neutralization temperature is 50-70°C, and the neutralization time is 20-40 min; the germanium content in the distillation residue is 4.42-32.19 mg / L, the zinc content is 0.10-1.10 g / L, and the iron content is 49.56- The content of germanium in the distillation residue is 0.11~2.15%, the content of zinc is 0.20~0.75%, the content of iron is 16.83~17.31%, the content of lead is 5.09~6.43%, and the content of silicon dioxide is 10.96~15.52% in terms of mass percentage.

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