Comprehensive recovery method of zinc-germanium-containing concentrate chlorination distillation residual liquid

Abstract

The comprehensive recovery method comprises the following steps: extracting germanium from a germanium-containing zinc sulfate solution by using an extraction method, reversely extracting the germanium by using acid or alkali to obtain germanium-containing strip liquor, and adding zinc ions as a settling aid for neutralizing, hydrolyzing and precipitating to prepare germanium concentrate; the method comprises the following steps: chloridizing and distilling concentrate containing zinc and germanium, neutralizing distillation residual liquid with ammonium bicarbonate or ammonium carbonate until the pH is equal to 2-3, adding ammonium sulfate for decalcification, filtering CaS04, and continuously neutralizing with ammonium bicarbonate or ammonium bicarbonate until the pH is equal to 6-7 to obtain basic zinc carbonate precipitate; the precipitated liquid is subjected to low-temperature and reduced-pressure evaporation concentration to crystallize ammonium chloride which is used as an electric zinc ingot casting slag former; and the residual germanium-containing crystallization mother liquor is returned to chlorination distillation or is used as a neutralizer of distillation residual liquid. According to the method, the effective components in the zinc-germanium-containing concentrate chlorination distillation raffinate are comprehensively and efficiently recovered, and the germanium-containing chlorination distillation raffinate is well treated.

Description

Technical Field

[0001] The present invention belongs to the field of hydrometallurgy, and specifically relates to a comprehensive recovery method for the residual liquid of chlorinated distillation of zinc-germanium concentrate, that is, extracting germanium from a germanium-containing zinc sulfate solution by an extraction method, and adding Zn to the stripping solution after stripping germanium. 2+ It is used as a precipitation aid to neutralize and hydrolyze the germanium concentrate. The germanium concentrate is subjected to chlorination distillation with CaCl2 as a chloride ion activator to comprehensively recover zinc, ammonium chloride and residual germanium from the distillation residue. Background Art

[0002] The main development direction of the wet extraction technology of germanium is to extract germanium from the germanium-containing zinc sulfate solution by extraction method, and then strip the germanium, and then neutralize and hydrolyze the stripping solution to produce germanium concentrate. In order to make the germanium in the stripping solution be well neutralized and hydrolyzed, Zn is added. 2+ As a sedimentation aid, adding Ca 2+ ,Mg 2+ , Fe 2+ etc. is better. Add Zn according to Zn / Ge = 1 to 1.5 2+ The primary hydrolysis precipitation rate of germanium can reach more than 98%. However, the zinc content of the produced germanium concentrate is 1 to 1.2 times that of the germanium grade. After the germanium concentrate is chlorinated and distilled, zinc is converted into ZnCl 2 or ZnCl4 -2 The distillation residue needs to be recycled. In order to increase the chlorination distillation rate of germanium, CaCl2 needs to be added as a chloride ion activator. Therefore, the chlorination distillation residue of germanium also contains Ca 2+ . At present, the treatment of chlorinated distillation residues containing zinc, calcium, and residual germanium mainly adopts lime or alkali to neutralize to pH=8 so that zinc, calcium, etc. are hydrolyzed and precipitated as hydroxides for recovery. Sodium chloride and calcium chloride in the liquid after hydrolysis and precipitation are not recovered. Even if concentrated crystallization is carried out for recovery, the economic value of sodium chloride and calcium chloride is low, and the products cannot be reused or sold, and can only be stored for treatment. Therefore, after the hydrolysis and precipitation of zinc in the chlorinated distillation residue, the filtrate is mostly incorporated into other wastewater for treatment.

[0003] Chinese patent CN10806035A discloses the use of N 235 Technology for recovering indium and germanium from chlorinated distillation residues containing indium and germanium. Indium is InCl 4- or InCl6 -3 Negative ions are N 235 Extraction, residual germanium added tartaric acid and N 235 Extraction, sodium chloride is used for brine electrolysis to recover chlorine and NaOH, suggesting that the comprehensive recovery of germanium concentrate chlorination distillation residue can be carried out by extraction and electrolysis. However, the residue does not contain zinc, and sodium chloride needs to be concentrated to more than 50g / L before electrolysis can be carried out. The process is long, energy consumption is high, and equipment investment is large. Chinese patent CN102732722B discloses that zinc can be ZnCL4-2 Negative ions are N 235 The extraction technology indicates that zinc is mainly present as ZnCl4 under high chloride content and certain pH conditions. -2 Negative ions exist and can be 235 Extraction recovery. 235 After extraction, NaOH must be used for back extraction to obtain a mixed solution of Na2ZnO2 and NaCl. After hydrolysis of zinc precipitation or electrolysis of zinc powder, the NaCl residual liquid needs to be managed. The raffinate after extraction contains a large amount of chloride ions, and calcium ions still need to be treated for wastewater, making the management of the chlorination distillation residual liquid containing zinc-germanium concentrate more complicated. Therefore, the comprehensive recovery of the chlorination distillation residual liquid containing zinc-germanium concentrate cannot be fully achieved by the extraction method. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned technologies for treating the residual liquid of chlorination distillation of zinc-germanium concentrate, the present invention provides a comprehensive recovery method for the residual liquid of chlorination distillation of zinc-germanium concentrate, which comprises the following steps: neutralization is performed in two stages with ammonium carbonate or ammonium bicarbonate, and ammonium sulfate is used for decalcification after the first neutralization; basic zinc carbonate is recovered in the second neutralization; the liquid after zinc recovery is evaporated, concentrated and crystallized to recover ammonium chloride, which is used as a slag-forming agent for electrolytic zinc smelting; the mother liquor containing germanium crystal is returned to the chlorination distillation to recover germanium or to be used as a neutralizing agent. The technical process can realize the comprehensive recovery and utilization of the residual liquid of chlorination distillation of zinc-germanium concentrate, and the recovered product has good economic value; except for the production of a small amount of calcium sulfate slag, there is no other waste slag, wastewater is discharged, the process flow is simple, and the equipment investment is small.

[0005] A comprehensive recovery method for chlorinated distillation residue containing zinc-germanium concentrate, comprising the following steps:

[0006] Step 1, extracting germanium from a germanium-containing zinc sulfate solution by an extraction method, and stripping germanium to obtain a germanium-containing stripping solution;

[0007] Step 2, adding Zn to the germanium-containing stripping solution in step 1 2+ As a precipitation aid, the germanium is then neutralized and hydrolyzed to precipitate the germanium to obtain a zinc-germanium concentrate;

[0008] Step 3, subjecting the zinc-germanium concentrate of step 2 to chlorination distillation under the condition of adding CaCl2 as a chloride ion activator to obtain GeCl4 and a distillation residue containing Ge<0.3g / L, ZnCl2, CaCl2 and 6NHCl;

[0009] Step 4, neutralizing the chlorinated distillation residue in step 3 with lime or NH4HC03 or (NH4)2C03 to a pH of 2 to 3, then adding ammonium sulfate for decalcification, and filtering the CaS04 precipitate to obtain a filtrate;

[0010] Step 5, neutralizing the filtrate of step 4 with ammonium bicarbonate or ammonium carbonate to a pH of 6 to 7 to obtain basic zinc carbonate precipitate and ammonium chloride filtrate;

[0011] Step 6, the ammonium chloride filtrate of step 5 is concentrated by low-temperature and reduced-pressure evaporation to obtain an ammonium chloride crystal product for use as a slag-making agent for metal zinc ingots; the crystallization mother liquor containing residual germanium is returned to step 3 for chlorination distillation or returned to step 4 for use as a neutralizing agent.

[0012] Furthermore, the extraction method in step 1 uses Lix63 or yw100 or 7815 hydroxamic acid extractants, or uses N 235 Amine extractants; germanium stripping is carried out with acid or base.

[0013] Furthermore, the Zn added in step 2 2+ Provided by ZnS04, preferably using the zinc sulfate raffinate containing zinc in step 1, Zn 2+ The dosage is zinc / germanium = 1 to 1.5.

[0014] Furthermore, the low-temperature and reduced-pressure evaporation conditions of the ammonium chloride filtrate in step 6 are: reduced pressure <0.8 atmospheres, temperature 40-60° C., and evaporation and concentration until a large amount of NH 4 Cl crystals are produced.

[0015] Working principle and features of the present invention:

[0016] When germanium is extracted by extraction method and neutralized and hydrolyzed and precipitated after stripping, divalent or trivalent metal ions must be added as precipitation aids to make the hydrolysis and precipitation rate of germanium in the stripping solution reach more than 98%.

[0017] When calcium and magnesium ions are added as precipitation aids, at the optimal hydrolysis precipitation pH of germanium = 9-11, in addition to the formation of calcium germanate or magnesium germanate precipitates, a large amount of Ca(0H)2 or Mg(0H)2 precipitates are also formed, affecting the grade of the germanium concentrate.

[0018] When using trivalent iron or trivalent aluminum, Fe(0H)3 or Al(0H)3 colloid is generated first, and then germanium is adsorbed and precipitated, but it is difficult to filter. 2+ As a precipitation aid, zinc germanate precipitation can be generated. Since zinc has both acid and alkaline properties, excess zinc can generate sodium zincate when the pH is above 9 and dissolve in alkaline solution. It does not exist as Zn(0H)2, so it does not affect the grade of germanium concentrate.

[0019] Using zinc as a precipitation aid, the hydrolysis precipitation rate of germanium is more than 98.5%, and the grade of germanium concentrate is about 30%. Since zinc / germanium is added at a ratio of 1 to 1.5, the content of zinc in the germanium concentrate is more than 1 times that of germanium. After the germanium concentrate is subjected to chlorination distillation, the zinc in the residual liquid can reach more than 20g / L, and the highest can reach 50 to 60g / L, which has recovery value.

[0020] Chlorination distillation of germanium concentrate generally requires the addition of metal chloride as an activator for chloride ions. Since the solubility of CaCl2 in the solution is much greater than that of NaCl, CaCl2 is added as an activator in the chlorination distillation of germanium concentrate. A certain amount of calcium ions are contained in the distillation residue. In order to recover chloride ions, the present invention must decalcify. When the 6N HCl residual liquid is neutralized to pH = 2-3, ammonium sulfate solution is added to generate calcium sulfate precipitation for removal. After filtration, the residual liquid mainly contains ZnCL2, NH4Cl, HCl and residual germanium. Continue to neutralize with ammonium carbonate or ammonium bicarbonate to pH = 6-7, and a large amount of basic zinc carbonate will be precipitated. After filtration, the filtrate mainly contains NH4CL and residual germanium.

[0021] The filtrate is concentrated by low temperature and reduced pressure evaporation, the purpose is to prevent the ammonium chloride from volatilizing and escaping, and to accelerate the evaporation of water and the concentrated crystallization of ammonium chloride. The remaining germanium does not crystallize with the ammonium chloride, but remains in the crystallization mother liquor and is enriched. When the germanium in the crystallization mother liquor is enriched to more than 1g / L, it is returned to the chlorination distillation for recovery. When it is less than 1g / L, it is returned to step 4 for use as a neutralizing agent, and the remaining germanium is not lost.

[0022] The beneficial effect of the present invention is to promote the extraction of germanium from a germanium-containing zinc sulfate solution by an extraction method, and to use Zn 2+ Through the development of the technology of neutralization and hydrolysis precipitation aid, the effective components in the chlorination distillation residue of zinc-germanium concentrate can be comprehensively and efficiently recovered, and the chlorination distillation residue of germanium can be better treated. DETAILED DESCRIPTION

[0023] The present invention is further illustrated by the following examples.

[0024] Embodiment: A comprehensive recovery method for the residual liquor of chlorination distillation of zinc-germanium concentrate, which comprises the following steps: neutralization is performed in two stages with ammonium carbonate or ammonium bicarbonate, and decalcification is performed with ammonium sulfate after the first neutralization; basic zinc carbonate is recovered in the second neutralization; the liquid after zinc recovery is evaporated, concentrated and crystallized to recover ammonium chloride, which is used as a slag-making agent for electrolytic zinc smelting; the mother liquor containing germanium crystallization is returned to the chlorination distillation to recover germanium or to be used as a neutralizing agent. The technical process can realize the comprehensive recovery and utilization of the residual liquor of chlorination distillation of zinc-germanium concentrate, and the recovered product has good economic value; except for a small amount of calcium sulfate slag, there is no other waste slag, wastewater discharge, simple process flow and small equipment investment.

[0025] The specific implementation steps are as follows:

[0026] Step 1, extracting germanium from the germanium-containing zinc sulfate solution by an extraction method, and stripping germanium to obtain a germanium-containing stripping solution. The extraction method can be to use hydroxamic acid or hydroxamic acid to chelate the germanium, to strip germanium with a high acid solution or an ammonium sulfate mixed solution, or to use N 235Amines are used to extract germanium anions, and NaOH is used to back-extract germanium.

[0027] Step 2, adding Zn to the germanium stripping solution in step 1 2+ It is used as a precipitation aid for neutralization and hydrolysis to obtain zinc-germanium concentrate.

[0028] Step 3, the germanium concentrate of step 2 is subjected to chlorination distillation using CaCl2 as a chloride ion activator to obtain GeCl4 and a chlorination distillation residue containing zinc, calcium, and residual germanium. The residue contains about 200g / L of chloride ions, more than 20g / L of zinc, less than 0.3g / L of residual germanium, and about 6N of HCl.

[0029] Step 4, neutralizing the chlorinated distillation residue in step 3 with lime or ammonium carbonate or ammonium bicarbonate to a pH of 2-3, then adding ammonium sulfate to decalcify to less than 1 g / L, and filtering the calcium sulfate to obtain a filtrate.

[0030] Step 5, further neutralizing the filtrate of step 4 with ammonium carbonate or ammonium bicarbonate to pH=6-7 to obtain basic zinc carbonate precipitate and ammonium chloride filtrate.

[0031] Step 6, the ammonium chloride filtrate of step 5 is concentrated by low temperature and reduced pressure evaporation to obtain ammonium chloride crystal product for use as a slag making agent for metal zinc ingot or for sale. When the germanium-containing crystal mother liquor reaches a germanium content of more than 1g / L, it is returned to chlorination distillation to recover germanium. When it is less than 1g / L, it is returned to step 4 for use as a neutralizing agent.

[0032] Example 1:

[0033] A company uses N 235 The kerosene extractant extracts germanium from the germanium-containing zinc sulfate solution, and the germanium is stripped with a NaOH solution. After repeated recycling and enrichment, the stripping solution contains 15.6 g / L germanium and 8.3 g / L zinc. The raffinate is used to supplement Zn at a total zinc / germanium ratio of 1.2. 2+ , then neutralized to pH=10 for hydrolysis. Obtain zinc germanate hydrolysis precipitate, the liquid after hydrolysis contains Ge0.5g / L. Dry the zinc germanate precipitate to obtain germanium concentrate containing 28.3% germanium and 33.5% zinc. Then use 5% CaCl2, 12N hydrochloric acid, liquid / solid=2 for chlorination distillation to obtain GeCl4 and distillation residue containing 0.3g / L Ge, 25.3g / L Zn, 8.5g / L Ca, and 6N HCL, and carry out comprehensive recovery and treatment of the distillation residue.

[0034] Step 1, neutralize with ammonium carbonate to pH=3, and add (NH4)2S04 to decalcify to 0.8g / L.

[0035] Step 2: After filtering, continue to neutralize with ammonium carbonate or ammonium bicarbonate to pH=6.5 to obtain a large amount of basic zinc carbonate precipitate and a precipitate filtrate containing Zn<1 g / L.

[0036] Step 3, evaporating and concentrating at a temperature of 50° C. and reducing the pressure to 0.8 atm for 8 hours to obtain NH 4 Cl crystal product and a crystallization mother liquor containing 0.85 g / L of germanium.

[0037] In step 4, the crystallization mother liquor is returned to step 1 for use as a neutralizing agent, and the ammonium chloride product is used as a slag agent for electro-zinc smelting.

[0038] The comprehensive recovery rate of zinc is 95.2%, and the direct recovery rate of ammonium chloride product is 65.3%.

[0039] Example 2:

[0040] Use P 204 _ Hydroxamic acid kerosene extractant, extract germanium from the germanium-containing zinc sulfate solution, use ammonium sulfate solution to strip germanium, and use it repeatedly to enrich the ammonium sulfate stripping solution to 30.5g / L of germanium. Then add Zn at a ratio of zinc / germanium = 1.5 2+ , neutralized with NaOH to pH=11 to hydrolyze and precipitate germanium. The hydrolysis residue contains 0.8g / L germanium, and the hydrolysis precipitate is dried to obtain a germanium concentrate containing 40% zinc and 32.5% germanium. Then, the germanium concentrate is chlorinated and distilled according to the chlorination distillation conditions of Example 1, and the basic zinc carbonate and ammonium chloride of the distillation residue are comprehensively recovered according to the steps of Example 1. The comprehensive recovery rate of zinc is 93.2%, and the direct recovery rate of ammonium chloride product is 63.5%. The crystallization mother liquor contains 1.3g / L germanium, which is returned to the chlorination distillation to recover germanium.

[0041] The invention uses ammonium carbonate or ammonium bicarbonate for two-stage neutralization, and uses ammonium sulfate for decalcification after the first stage of neutralization; the second stage of neutralization recovers basic zinc carbonate; the liquid after zinc recovery is evaporated, concentrated and crystallized to recover ammonium chloride, which is used as a slag-making agent for electrolytic zinc metal casting; the mother liquor containing germanium crystal is returned to the chlorination distillation to recover germanium or to be used as a neutralizing agent. The technical process can realize the comprehensive recovery and utilization of the residual liquid of the chlorination distillation of zinc-germanium concentrate, and the recovered product has good economic value; except for the output of a small amount of calcium sulfate slag, there is no other waste slag, wastewater discharge, simple process flow and small equipment investment.

[0042] The above examples are only used to further illustrate the present invention, and the present invention is not limited thereto.

Claims

1. A comprehensive recovery method for chlorinated distillation residue containing zinc-germanium concentrate, characterized in that: The following steps are involved: Step 1, extracting germanium from a germanium-containing zinc sulfate solution by an extraction method, and stripping germanium to obtain a germanium-containing stripping solution; Step 2, adding Zn to the germanium-containing stripping solution in step 1 2+ As a precipitation aid, the germanium is then neutralized and hydrolyzed to precipitate the germanium to obtain a zinc-germanium concentrate; Step 3, subjecting the zinc-germanium concentrate of step 2 to chlorination distillation under the condition of adding CaCl2 as a chloride ion activator to obtain GeCl4 and a distillation residue containing Ge<0.3g / L, ZnCl2, CaCl2 and 6NHCl; Step 4, neutralizing the chlorinated distillation residue in step 3 with lime or NH4HC03 or (NH4)2C03 to a pH of 2 to 3, then adding ammonium sulfate for decalcification, and filtering the CaS04 precipitate to obtain a filtrate; Step 5, further neutralizing the filtrate of step 4 with ammonium bicarbonate or ammonium carbonate to a pH of 6 to 7 to obtain basic zinc carbonate precipitate and ammonium chloride filtrate; Step 6, the ammonium chloride filtrate of step 5 is concentrated by low-temperature and reduced-pressure evaporation to obtain an ammonium chloride crystal product for use as a slag-making agent for metal zinc ingots; the crystallization mother liquor containing residual germanium is returned to step 3 for chlorination distillation or returned to step 4 for use as a neutralizing agent.

2. A comprehensive recovery method for chlorinated distillation residue containing zinc-germanium concentrate as claimed in claim 1, characterized in that: The extraction method of step 1 uses Lix63 or YW100 or 7815 hydroxamic acid extractant, or uses N 235 Amine extractants; germanium stripping is carried out with acid or base.

3. A comprehensive recovery method for chlorinated distillation residue containing zinc-germanium concentrate as claimed in claim 1, characterized in that: The Zn added in step 2 2+ Provided by ZnS04, preferably using the zinc sulfate raffinate containing zinc in step 1, Zn 2+ The dosage is zinc / germanium = 1 to 1.

5.

4. A comprehensive recovery method for chlorinated distillation residue containing zinc-germanium concentrate as claimed in claim 1, characterized in that: The low-temperature and reduced-pressure evaporation conditions of the ammonium chloride filtrate in step 6 are: reduced pressure <0.8 atmospheres, temperature 40-60° C., and evaporation and concentration until a large amount of NH 4 Cl crystals are produced.