阅读说明：本技术 一种从含锗烟尘中回收二氧化锗的方法 (Method for recovering germanium dioxide from germanium-containing smoke dust ) 是由 岳喜龙 许�鹏 冯修全 樊红杰 李静 何国英 于 2019-11-18 设计创作，主要内容包括：一种从含锗烟尘中回收二氧化锗的方法,涉及锗冶金技术领域,将含锗烟尘通过两级碱法浸出后,再采用过滤、净化、沉淀的方法回收二氧化锗。采用本发明的工艺方法,锗的回收率可达到90%以上,且可实现氨水、氢氧化钠及镁盐等药剂的循环使用。此工艺过程的提出,对于解决此类烟尘传统酸法处理过程中锗的回收率低、消耗大、回收成本高、资源利用率低、环境污染严重等问题有十分积极的意义。(A method for recovering germanium dioxide from germanium-containing smoke dust relates to the technical field of germanium metallurgy, and the germanium dioxide is recovered by leaching the germanium-containing smoke dust through a two-stage alkaline process and then adopting a method of filtering, purifying and precipitating. By adopting the process method, the recovery rate of germanium can reach more than 90 percent, and the recycling of medicaments such as ammonia water, sodium hydroxide, magnesium salt and the like can be realized. The technical process has positive significance for solving the problems of low recovery rate, high consumption, high recovery cost, low resource utilization rate, serious environmental pollution and the like of the germanium in the traditional acid method treatment process of the smoke dust.)

1. A method for recovering germanium dioxide from germanium-containing smoke dust is characterized by comprising the following steps;

1) primary circulating leaching: under the condition of 40-80 ℃, mixing germanium-containing smoke dust and a first leaching agent consisting of ammonia water and hydrogen peroxide in a first closed container for leaching for 2-5 hours, filtering, washing filter residues, combining filtrate, supplementing ammonia water and hydrogen peroxide, returning to a first closed mixer for continuous leaching, and circulating for 3-5 times to obtain a first germanium-containing solution and first leaching residues;

2) hydrolyzing and precipitating germanium: evaporating and concentrating the first germanium-containing solution to dryness to obtain first crude germanium dioxide;

3) secondary circulating leaching: mixing and leaching the first leaching residue and a second leaching agent at 100-125 ℃ for 2-5 hours, wherein the second leaching agent is at least formed by mixing sodium hydroxide, sodium hypochlorite and sodium carbonate, filtering, washing filter residues, combining filter liquor, supplementing sodium hydroxide, sodium hypochlorite and sodium carbonate, returning to a second closed container for continuous leaching, and circulating for 3-6 times to respectively obtain a second germanium-containing solution and second leaching residue;

4) and (3) depositing germanium by using magnesium salt: mixing and stirring the second germanium-containing solution and magnesium salt in a precipitation kettle at 40-80 ℃ for reaction until the reaction is finished, standing, filtering and washing to respectively obtain alkaline filtrate and germanium-magnesium enriched slag;

5) extracting and separating germanium and magnesium: dissolving germanium and magnesium enriched slag in sulfuric acid or hydrochloric acid solution, taking at least one of di (2-ethylhexyl) phosphate, di (2-ethylhexyl) phosphate and dinonylnaphthalenesulfonic acid as an extracting agent, and respectively obtaining a magnesium-loaded organic phase and germanium raffinate through extraction separation;

6) neutralizing and depositing germanium: neutralizing and hydrolyzing the germanium raffinate with alkali, filtering and drying to respectively obtain second crude germanium dioxide and neutralized liquid;

7) refining germanium dioxide: and purifying and refining the first coarse germanium dioxide and the second coarse germanium dioxide to obtain a germanium dioxide product.

2. The method for recovering germanium dioxide from germanium-containing soot as claimed in claim 1, wherein the mixing mass ratio of the first leaching agent to the germanium-containing soot in the primary circulation leaching process is 3-5: 1; NH in the first mixed leaching agent₃、H₂O₂The concentration of the water-soluble organic solvent is 100-200 g/l and 1-10 g/l.

3. The method as claimed in claim 1, wherein during the hydrolysis germanium precipitation, the evaporated vapor generated by evaporation and concentration is condensed to obtain ammonia water, and the ammonia water is returned to the primary circulation leaching.

4. The method for recovering germanium dioxide from germanium-containing smoke dust according to claim 1, wherein in the secondary cycle leaching process, the mixing mass ratio of the second leaching agent to the first leaching residue is 3-6: 1, and NaOH, NaClO and Na in the second leaching agent are₂CO₃The concentration of the water-soluble organic solvent is 100-200 g/l, 1-10 g/l, 10-50 g/l.

5. The method of claim 1, wherein the second leaching agent further comprises BaCl during the secondary cycle leaching process₂And Fe₂(SO₄)₃Said BaCl₂、Fe₂(SO₄)₃The mixing mass ratio of the first leaching residue to the first leaching residue is 0.01-0.05: 1.

6. The method of claim 1, wherein the magnesium salt is magnesium sulfate or magnesium chloride during the germanium precipitation.

7. The method for recovering germanium dioxide from germanium-containing smoke according to claim 6, wherein the molar ratio of magnesium to germanium in the germanium precipitation process of the magnesium salt is 2-5: 1, the mixing and stirring reaction time is 10-30 min, and the standing time is 30-120 min.

8. The method for recovering germanium dioxide from germanium-containing soot as claimed in claim 1, 6 or 7, wherein the alkaline filtrate separated during the germanium precipitation process of magnesium salt is returned for use as leaching agent in the secondary cycle leaching process.

9. The method of claim 1, wherein during the germanium-magnesium extraction separation, the magnesium-loaded organic phase is stripped with sulfuric acid or hydrochloric acid to obtain a magnesium-containing strip solution, and the magnesium-containing strip solution is evaporated and concentrated to obtain a magnesium salt solution.

10. The method of claim 9, wherein the stripped organic phase is washed with a washing solution to obtain a regenerated organic phase and a washing solution, and the washing solution is returned to neutralize and precipitate germanium.

Technical Field

The invention relates to the field of metallurgical production of germanium.

Background

The germanium-containing smoke dust is low-grade germanium-containing waste residues, is mostly derived from germanium distillation residues, germanium recovery processing wastewater sludge, germanium coal combustion gravity dust and the like, is cloth bag dust obtained after pyrogenic volatilization, is in the form of grey powder, contains 1-3 wt% of germanium, and comprises most of calcium oxide, silicon dioxide and a small amount of metal impurities such as lead, arsenic, zinc, iron and the like. The main components are as follows: 1-3 wt% of germanium, Ca: 5 to 8 wt% of SiO₂：60～75 wt%，As：0.05～0.1 wt%、Zn：0.05～0.1 wt%、Pb：0.01～0.02 wt%，Fe：0.1～0.3 wt%。

Hitherto, the following methods have been used to recover germanium from germanium-containing soot:

1. the pyrogenic recovery method comprises the following steps:

for example, CN201811446047.5 discloses a method for enriching germanium from germanium-containing lignite smoke dust, wherein the germanium-containing lignite smoke dust comprises 0.2-1.5 wt% of germanium, 10-20 wt% of silicon and 10-40 wt% of carbon, the germanium-containing lignite smoke dust, coal powder and vulcanizing agent are uniformly mixed according to the mass ratio of 1: 0.10-0.20: 0.05-0.20 to prepare pellet particles, and the pellet particles are dehydrated and dried at 100 ℃; and (3) placing the dried pellet particles in a closed furnace, heating to 600 ℃, introducing air, continuously heating to 800-1200 ℃, vulcanizing, heating for 2-6 hours to obtain pellet residues, and obtaining the germanium concentrate in a dust collector.

For another example, CN201510354223.2 discloses a method for recovering germanium from lignite smoke dust, which utilizes vacuum reduction-chlorination distillation technology to recover germanium from lignite smoke dust, firstly, putting lignite smoke dust and 5-25 wt% of coke into a vacuum heating furnace together, and performing vacuum reduction reaction at 800-1000 ℃ to obtain a product containing metal Ge, GeO and some impurities such As₂O₃The condensed product of (a); then chlorination distillation is carried out on the condensation product to obtain pure GeCl₄The purity is more than 90%; then to GeCl₄Hydrolyzing to obtain GeO₂。

2. The wet recovery method comprises the following steps:

for example, CN201110132101.0 germanium-containing flue gas germanium leaching and enriching method in power plant discloses a germanium-containing flue gas leaching process in power plant, the method is: firstly, useRepeatedly carrying out acid leaching for 5-10 times, wherein the initial acid is 0.2-0.3N, and the final acid is 0.25-0.05N; then Na is added again₂CO₃Alkaline leaching for 2-3 times with Na₂CO₃The dosage is 20-30% of the input amount, the pH value is 12-14, acidification is carried out after boiling and stirring for 0.5 hour, and stirring is carried out for 15-20 minutes after acidification; precipitating germanium from the solution after acid leaching and alkali leaching by using tannin, performing filter pressing, and performing filter pressing on the tannin precipitation solution by using an acid-resistant medium to obtain a filter cake containing 60-70% of water, namely the tannin germanium; and drying the tannin germanium filter cake until the water content is below 8%, and then roasting to obtain the germanium enriched by 100-120 times.

Also for example, CN201310070847.2 discloses a method for recovering germanium from germanium-containing soot, which comprises crushing and sieving germanium soot, stirring and mixing water and germanium soot uniformly; adding industrial sulfuric acid, and continuously stirring at 85-90 ℃ until no gas is generated in the slurry; adding H under the stirring condition of 50-70 DEG C₂O₂Up to H₂O₂The complete decomposition has no bubble generation; filtering the obtained slurry, adding industrial hydrochloric acid, heating, and distilling for 2-4 hours by using distilled water as an absorbent to obtain a distillate I; and carrying out secondary distillation to obtain a distillate II, hydrolyzing the distillate II, filtering and drying to obtain the high-purity germanium dioxide powder.

For another example, CN201610395212.3 discloses a process for extracting GeCl from germanium-containing soot₄The method comprises the following steps: mixing materials: mixing germanium-containing smoke dust and hydrochloric acid according to the weight ratio of 1: 1.25-13.5, and carrying out microwave heating: heating the mixed materials to a temperature higher than the distillation temperature of germanium tetrachloride by microwave for distillation, and stirring simultaneously; collecting the distilled product, i.e. GeCl₄。

Also, CN201110294901.2 discloses a method for recovering germanium from germanium smoke by microwave heating and alkali fusion, in which germanium-containing smoke is mixed with sodium hydroxide and then heated under microwave to obtain alkali fused material; and then adding the mixture into hot water for dissolving, filtering and separating after dissolving, and removing filter residues to obtain the germanium-containing liquid.

In addition, in "rare metals" 2006S1 "discussion of process for extracting germanium from germanium-containing soot", a method of roasting at low temperature, distilling and recovering most of germanium with hydrochloric acid, leaching residue with sodium hydroxide, precipitating tannin, roasting again and distilling to recover germanium is reported.

The method can be used for the recovery and industrial application of most of the germanium-containing smoke dust at present, and adopts the way of acid treatment and subsequent recovery of germanium, or directly utilizes hydrochloric acid distillation to obtain crude germanium tetrachloride. The processes have great problems, such as increased cost due to the use of a large amount of acid liquor, great potential safety hazard of sulfuric acid or hydrochloric acid, great environmental problems caused by the use of a large amount of acid, and the like.

In addition, the related documents and patent technologies disclose secondary pyrogenic volatilization enrichment methods, which have the problems of smoke pollution and germanium loss in slag, and have high energy consumption, and need to use fuels such as coal or coke.

There are also related documents and patents reporting that the conditions of alkali fusion or alkali leaching treatment methods are correspondingly pretreated, a large amount of acid is needed for neutralizing alkali to recover germanium, and the alkali used in the above processes cannot be recycled, so that the economical efficiency is low.

Disclosure of Invention

In view of the above disadvantages, the present invention aims to provide a method for recovering germanium dioxide from germanium-containing soot, which adopts a cheap alkaline agent, and realizes the recycling of the alkaline agent while efficiently recovering germanium.

The method comprises the steps of primary circulating leaching, hydrolysis germanium precipitation, secondary circulating leaching, magnesium salt germanium precipitation, germanium and magnesium extraction separation, neutralization germanium precipitation and germanium dioxide refining, and specifically comprises the following steps:

1) primary circulating leaching: under the condition of 40-80 ℃, mixing germanium-containing smoke dust and a first leaching agent consisting of ammonia water and hydrogen peroxide in a first closed container for leaching for 2-5 hours, filtering, washing filter residues, combining filtrate, supplementing ammonia water and hydrogen peroxide, returning to a first closed mixer for continuous leaching, and circulating for 3-5 times to obtain a first germanium-containing solution and first leaching residues;

2) hydrolyzing and precipitating germanium: evaporating and concentrating the first germanium-containing solution to dryness to obtain first crude germanium dioxide;

3) secondary circulating leaching: mixing and leaching the first leaching residue and a second leaching agent at 100-125 ℃ for 2-5 hours, wherein the second leaching agent is at least formed by mixing sodium hydroxide, sodium hypochlorite and sodium carbonate, filtering, washing filter residues, combining filter liquor, supplementing sodium hydroxide, sodium hypochlorite and sodium carbonate, returning to a second closed container for continuous leaching, and circulating for 3-6 times to respectively obtain a second germanium-containing solution and second leaching residue;

4) and (3) depositing germanium by using magnesium salt: mixing and stirring the second germanium-containing solution and magnesium salt in a precipitation kettle at 40-80 ℃ for reaction until the reaction is finished, standing, filtering and washing to respectively obtain alkaline filtrate and germanium-magnesium enriched slag;

5) extracting and separating germanium and magnesium: dissolving germanium and magnesium enriched slag in sulfuric acid or hydrochloric acid solution, taking at least one of di (2-ethylhexyl) phosphate (P204), di (2-ethylhexyl) phosphate (P507) and dinonylnaphthalene sulfonic acid (DNNSA) as an extracting agent, and extracting and separating to respectively obtain a magnesium-loaded organic phase and germanium raffinate;

6) neutralizing and depositing germanium: neutralizing and hydrolyzing the germanium raffinate with alkali, filtering and drying to respectively obtain second crude germanium dioxide and neutralized liquid;

7) refining germanium dioxide: and purifying and refining the first coarse germanium dioxide and the second coarse germanium dioxide to obtain a germanium dioxide product.

The invention changes the traditional process route of obtaining crude germanium tetrachloride by direct hydrochloric acid distillation, and respectively uses ammonia water and sodium hydroxide as main leaching agents to carry out twice circulating leaching, and after leaching, the germanium dioxide is recovered by adopting a separation and precipitation method. In the process of extracting and separating germanium and magnesium, the effective separation of germanium and magnesium is realized by utilizing the characteristic that bis (2-ethylhexyl) phosphate, bis (2-ethylhexyl) phosphate and dinonyl naphthalene sulfonic acid preferentially extract magnesium. Compared with the traditional hydrochloric acid distillation method, the method provided by the invention has the advantages that the recovery rate of germanium is improved, the recovery rate of germanium can reach above 90.77%, the recycling of main medicaments such as ammonia water, sodium hydroxide, magnesium salts and an extracting agent is realized, the production cost is reduced, the wastewater discharge is reduced, a short-flow and clean process is realized, and the method has a very positive significance for solving the problems of low recovery rate, high consumption, high recovery cost, low resource utilization rate, serious environmental pollution and the like of germanium in the traditional acid method treatment process of the smoke dust.

Furthermore, in the primary circulating leaching process, the mixing mass ratio (namely liquid-solid ratio) of the first leaching agent to the germanium-containing smoke dust is 3-5: 1; NH in the first mixed leaching agent₃、H₂O₂The concentration of the water-soluble organic solvent is 100-200 g/l and 1-10 g/l.

Its main advantage lies in:

1. compared with a hydrochloric acid system, the ammonia water is used as a main leaching system, the leaching of impurities such as arsenic, lead, calcium, iron, silicon and the like can be effectively inhibited, more than 70% of germanium can be recovered, and the effective separation of the germanium from the calcium, the arsenic, the lead, the calcium and the silicon dioxide is realized. 2. The leachate returns to the circulating leaching, the concentration of germanium in the leachate is further improved, after the leachate is circulated for 3-5 times, the concentration of germanium can reach 10-15g/l, even higher, and the subsequent deposition of germanium dioxide is facilitated. 3. The hydrogen peroxide oxidizes the bivalent germanium into tetravalent germanium, so that the leaching rate of the germanium is improved. 4. In the evaporation process, along with the volatilization of ammonia, the germanic acid ammonia is hydrolyzed into germanium dioxide, crude germanium dioxide is smoothly obtained, and the condensed ammonia water returns to be circularly leached, so that the ammonia utilization rate is improved.

And in the hydrolysis germanium precipitation process, condensing the evaporated steam generated by evaporation and concentration to obtain ammonia water. The ammonia water can be used as part of ammonia water in the first leaching agent of the primary cycle leaching for cycle use.

In the secondary cycle leaching process, the mixing mass ratio (namely liquid-solid ratio) of the second leaching agent to the first leaching residue is 3-6: 1, and NaOH, NaClO and Na in the second leaching agent₂CO₃The concentration of the water-soluble organic solvent is 100-200 g/l, 1-10 g/l, 10-50 g/l.

The second leaching agent also comprises BaCl₂And Fe₂(SO₄)₃Said BaCl₂、Fe₂(SO₄)₃The mixing mass ratio of the first leaching residue to the first leaching residue is 0.01-0.05: 1.

Its main advantage lies in:

1. the method is characterized in that sodium hydroxide is used as a main leaching system, so that germanium enters a solution in the form of sodium germanate, and undissolved germanium in a first stage of leaching residue, including germanium silicate, zinc germanate, calcium germanate, tetragonal germanium dioxide and the like, is recovered.

2. The second-stage leachate returns to be circularly leached, so that the concentration of germanium in the leachate is favorably improved; .

3. Sodium hypochlorite is added to generate oxidation, so that bivalent germanium can be oxidized into quadrivalent germanium, the leaching rate of the germanium is improved, and trivalent arsenic is oxidized into pentavalent germanium.

4. Barium chloride and ferric sulfate are added to lead arsenic to form a more stable arsenic-barium-iron-lead-zinc-silicon eutectic compound in the thermokalite solution, thereby realizing the effective separation of germanium from calcium, arsenic, lead, zinc, silicon dioxide and the like.

In the process of depositing germanium by using the magnesium salt, the magnesium salt is magnesium sulfate or magnesium chloride.

The molar ratio of magnesium to germanium in the process of depositing germanium in the magnesium salt is 2-5: 1, the mixing and stirring reaction time is 10-30 min, and the standing time is 30-120 min.

Its main advantage lies in:

1. germanium is precipitated by adopting magnesium salt to obtain germanium-magnesium enriched slag, so that the direct recovery of germanium in the solution of an alkaline system is realized, the whole precipitation process is very rapid, and magnesium germanate precipitated particles are large and easy to filter; magnesium salt is adopted to precipitate and separate germanium, so that a large amount of acid consumed by a neutralization method is avoided.

2. The germanium content in the germanium-magnesium-enriched slag obtained by precipitation is more than 15%, the magnesium salt consumption is too large, the germanium grade is reduced, and the optimal molar ratio of magnesium to germanium is 2-5: 1.

3. The liquid after the magnesium salt is precipitated and the germanium is returned to the second-stage circulating leaching to improve the utilization rate of alkali, and simultaneously, the germanium which is not completely precipitated is returned to be utilized again, so that loss is avoided.

And the alkaline filtrate obtained by separation in the process of depositing germanium in the magnesium salt is used as a leaching agent in the secondary circulating leaching process for return use.

In the germanium-magnesium extraction separation process, the magnesium-loaded organic phase is subjected to back extraction by sulfuric acid or hydrochloric acid to obtain magnesium-containing back extraction liquid, and the magnesium-containing back extraction liquid is evaporated and concentrated to obtain a recyclable magnesium salt solution.

Washing the organic phase after back extraction with alkali liquor to obtain regenerated organic phase and washing alkali liquor, and returning the washing alkali liquor to neutralize and precipitate germanium.

The regenerated organic phase can be used as part of the extractant to return to the germanium and magnesium extraction separation process.

In a word, the method can recover more than 90 percent of germanium from the germanium-containing smoke dust, which is far superior to the conventional direct hydrochloric acid distillation method (only about 70 percent), and has the advantages of high germanium utilization rate, greatly reduced cost, less generation amount of waste water, easy treatment and obvious cleanness and high efficiency because ammonia water, sodium hydroxide, magnesium salt and the like can be fully recycled in the treatment process of the method.

Drawings

FIG. 1 is a schematic process flow diagram of the present invention.

Detailed Description

First, the process route of the present invention is described in detail with reference to fig. 1.

1. Primary circulating leaching:

(1) the mechanism is as follows:

and (3) a germanium leaching process: germanium dioxide dissolves in ammonia water to form ammonia germanate, and germanium monoxide is oxidized to germanium dioxide.

GeO+H₂O₂=GeO₂+H₂O

GeO₂+2NH₃ ^.H₂O = (NH₄)₂GeO₃+H₂O

In the process, impurity metals such as iron, arsenic, calcium, lead, silicon and the like in the germanium-containing smoke dust do not participate in the reaction, and only 30-40 wt% of zinc is converted into complex ions. After cyclic leaching, a germanium solution containing more than 10g/l of germanium can be obtained.

(2) The treatment process comprises the following steps:

adding germanium-containing smoke dust, ammonia water and hydrogen peroxide into a first closed container, heating and maintaining at 40-80 ℃, simultaneously stirring and reacting for 2-5 hours, filtering and separating through a filter to obtain filtrate and filter residues respectively, washing the filter residues to obtain filtrate, combining the two filtrates, supplementing ammonia water and hydrogen peroxide, returning to a first closed mixer for continuous leaching, and repeating the steps for 3-5 times to obtain a first germanium-containing solution and first leaching residues.

The technical conditions for controlling the primary circulation leaching are as follows: the mixing mass ratio of the first leaching agent to the germanium-containing smoke dust is 3-5: 1. NH in the first mixed leaching agent₃、H₂O₂The concentration of the water-soluble organic solvent is 100-200 g/l and 1-10 g/l.

(3) The implementation results are as follows:

after one-time circulating leaching, a first germanium-containing solution and first leaching slag are obtained.

The concentration of germanium in the first germanium-containing solution is more than 10g/l, and the leaching rate of germanium is more than 70%.

2. Hydrolyzing and precipitating germanium:

(1) the mechanism is as follows:

the first germanium-containing solution is an ammonia water system, the ammonia concentration is gradually reduced along with the evaporation, germanic acid ammonia is decomposed to generate germanium dioxide precipitate, and the germanium dioxide precipitate is washed after being evaporated to dryness to obtain germanium dioxide. The ammonia water obtained by condensing and recovering the steam in the evaporation process can return to the primary cycle leaching process.

(NH₄)₂GeO₃——GeO₂+2NH₃

+H₂O

(2) The treatment process comprises the following steps:

and adding the first germanium-containing solution into an evaporation tank for continuous heating evaporation until the first germanium-containing solution is evaporated to dryness, connecting the evaporation tank with a condenser, and condensing and recovering the evaporated gas to obtain ammonia water. And after the hydrolysis germanium precipitation is finished, taking out the precipitate in the tank, adding water for washing, and filtering and drying to obtain first crude germanium dioxide.

(3) The treatment effect is as follows:

the content of germanium in the obtained first coarse germanium dioxide is more than 60 percent, and the recovery rate of germanium is more than 99.5 percent.

And condensing the evaporated steam generated by evaporation and concentration, and returning all the ammonia water obtained by condensation to one-time cyclic leaching for utilization.

3. Secondary circulating leaching:

(1) the mechanism is as follows:

in the germanium-containing smoke dust, calcium germanate, germanium silicate and acid-insoluble germanium dioxide are contained, the germanium is difficult to recover by an ammonia water system in a one-time circulating leaching process, and the part of germanium is easy to leach in an alkali thermal oxidation leaching process, and the related reaction equation is as follows:

GeO+2 NaOH= Na₂GeO₂+H₂O

Na₂GeO₂+NaClO = Na₂GeO₃+NaCl

GeO₂+2NaOH= Na₂GeO₃+H₂O

CaGeO₃+ 2NaOH = Na₂GeO₃+Ca(OH)₂

GeSiO₃+ 4NaOH = Na₂GeO₃+Na₂SiO₃+2H₂O

Na₂SiO₃+ Ca(OH)₂= CaSiO₃+2NaOH

ZnSiO₃+ 4NaOH = Na₂ZnO₂+Na₂SiO₃+2H₂O

PbSiO₃+ 4NaOH = Na₂PbO₂+Na₂SiO₃+2H₂O

in the reaction process, the reaction of arsenic is complex, 3-valent arsenic is oxidized into 5-valent arsenic, and finally the arsenic forms a more stable arsenic-barium-iron-lead-zinc eutectic compound in a hot alkali solution to be separated and removed. The excess barium combines with sulfate to form insoluble barium sulfate. In this process, the loss of germanium is less, and the related reaction equation is as follows:

As₂O₅+6NaOH=2 Na₃AsO₄+3H₂O

As₂O₃+6 NaOH+NaClO = 2Na₃AsO₄+NaCl+3H₂O

2AsO₄ ^3-+3Ba²⁺= Ba₃AsO₄)₂

2AsO₄ ^3-+3Pb²⁺= Pb₃(AsO₄)₂

AsO₄ ^3-+Fe³⁺= FeAsO₄

Ba²⁺+SO₄ ^2-= BaSO₄

the addition of sodium carbonate also promotes the conversion of calcium and lead into insoluble calcium carbonate and lead carbonate, and at the same time, the silicon dissolved out by alkali is converted into insoluble calcium silicate and lead silicate, thereby inhibiting the leaching of silicon.

Na₂PbO₂+Na₂CO₃+2H₂O=PbCO₃+4NaOH

Na₂SiO₃+Ca(OH)₂= CaSiO₃+2NaOH

And (3) carrying out cyclic leaching treatment on the first leaching residue obtained by the once cyclic leaching again by using the filtered leaching solution, and filtering and washing the first leaching residue after the cyclic leaching treatment is carried out for 3-6 times to obtain second leaching residue and a second germanium solution.

The second leaching slag generated in the secondary cycle leaching process can return to the pyrogenic process volatilization process to enrich germanium again.

(3) The treatment process comprises the following steps:

and adding the first leaching residue, sodium hydroxide, sodium hypochlorite, sodium carbonate, barium chloride, ferric sulfate and water into a second closed container, heating, keeping the temperature at 100-125 ℃, and stirring for leaching for 2-5 hours. Here, the second leaching agent is composed of a mixture of sodium hydroxide, sodium hypochlorite, sodium carbonate, barium chloride, iron sulfate and water.

The technical conditions for controlling the secondary circulation leaching are as follows: the mixing mass ratio of the second leaching agent to the first leaching residue is 3-6: 1, and NaOH, NaClO and Na in the second leaching agent₂CO₃The concentration of the water-soluble organic solvent is 100-200 g/l, 1-10 g/l, 10-50 g/l. With BaCl₂、Fe₂（SO₄）₃The mixing mass ratio of the first leaching residue to the first leaching residue is 0.01-0.05: 1.

And filtering and separating the reaction product by a filter after the reaction is finished, washing filter residues to obtain second leaching residues, combining the filtrate and the washing solution, returning the combined filtrate to a second closed container, supplementing sodium hydroxide, sodium hypochlorite and sodium carbonate according to controlled technical conditions, adding barium chloride and ferric sulfate, performing leaching reaction on the obtained product and the first leaching residues again, and circulating the reaction for 3-6 times to finally obtain a second germanium-containing solution and the second leaching residues.

(4) The treatment effect is as follows:

and after secondary circulating leaching treatment, obtaining a second germanium solution and second leaching residues, wherein the concentration of germanium in the second germanium solution is more than 5g/l, and the leaching rate of germanium is more than 70%.

4. And (3) depositing germanium by using magnesium salt:

(1) the mechanism is as follows: magnesium sulfate or magnesium chloride is added into the alkali solution as magnesium salt, and free germanium in the solution is combined with magnesium to quickly form magnesium germanate precipitate.

The main reaction is as follows:

Na₂GeO₃+2MgSO₄/MgCl₂=MgGeO₃+Na₂SO₄/2NaCl

the excess magnesium is precipitated as magnesium hydroxide. The magnesium hydroxide has good adsorption and flocculation effects, and is beneficial to the precipitation and recovery of germanium.

Mg²⁺+2NaOH=Mg(OH)₂

(2) The treatment process comprises the following steps:

and mixing and stirring the second germanium-containing solution and the magnesium salt solution in a precipitation kettle at 40-80 ℃ for reaction for 10-30 min, standing for 30-120 min after the reaction is finished, and filtering and washing to obtain alkaline filtrate and germanium-magnesium enriched slag respectively.

The molar ratio of magnesium to germanium in the process of depositing germanium from magnesium salt is 2-5: 1.

The alkaline filtrate can be returned to the secondary cycle leaching to fully utilize the alkali.

(3) The treatment effect is as follows:

and after the magnesium salt germanium precipitation reaction is finished, filtering, washing and drying to obtain germanium magnesium enriched slag containing more than 16% of germanium, wherein the recovery rate of germanium precipitation is more than 97%.

5. Extracting and separating germanium and magnesium:

(1) the mechanism is as follows:

in the germanium-magnesium enriched slag, germanium mainly exists in the form of magnesium germanate and is easily dissolved in sulfuric acid or hydrochloric acid. Therefore, after leaching, metal ions in the solution mainly comprise germanium and magnesium, the concentration of other impurity ions is low, the magnesium can be preferentially extracted under certain conditions by the bis (2-ethylhexyl) phosphate (P204), the bis (2-ethylhexyl) phosphate (P507) and the dinonylnaphthalenesulfonic acid (DNNSA), the germanium is not extracted basically, and the magnesium and the germanium have large extraction separation coefficients, so that the germanium and the magnesium are separated by adopting an extraction method.

(2) The treatment process comprises the following steps:

dissolving the germanium-magnesium enriched slag in a sulfuric acid or hydrochloric acid solution, taking at least one of di (2-ethylhexyl) phosphate (P204), di (2-ethylhexyl) phosphate (P507) and dinonylnaphthalene sulfonic acid (DNNSA) as an extracting agent, extracting and separating magnesium in the solution after the germanium-magnesium enriched slag is dissolved in the acid, and respectively obtaining a magnesium-loaded organic phase and a germanium-containing raffinate.

And carrying out back extraction on the loaded organic phase by adopting sulfuric acid or hydrochloric acid with certain concentration to obtain an organic phase and magnesium back extraction solution. Concentrating and crystallizing the stripping solution, and returning the obtained crystalline magnesium salt to the precipitation kettle for recycling.

The organic phase is washed by sodium hydroxide solution, a small part of germanium in the organic phase is back extracted, and then the organic phase is used as an extracting agent to return to the extraction separation process. The organic phase alkaline wash was used as raffinate neutralizer.

(3) The effect is as follows:

after extraction separation treatment, the magnesium concentration in the raffinate is lower than 0.1g/l, and the concentration ratio of germanium and magnesium is higher than 50.

6. Neutralizing and depositing germanium:

(1) the mechanism is as follows:

the raffinate is neutralized with alkali, and when the pH is neutral or weakly alkaline, germanium in the solution is hydrolyzed into germanium dioxide precipitate, so that the germanium dioxide precipitate is recovered.

The reaction formula is as follows:

Ge(SO₄)₂/GeCl₄+4NaOH=GeO₂+2Na2SO4/4NaCl+2H₂O

(2) the treatment process comprises the following steps:

and (3) performing neutralization hydrolysis on the germanium-containing raffinate, controlling the pH value to be 7-8 by using sodium hydroxide and an organic phase alkaline washing solution as a neutralizing agent, filtering, washing and drying to respectively obtain second crude germanium dioxide and neutralized liquid. The neutralized liquid is discharged after reaching the standard after being treated by waste water.

(3) The treatment effect is as follows:

after the treatment of neutralizing and germanium precipitation, the content of germanium in the obtained second coarse germanium dioxide is more than 60 percent.

7. Refining germanium dioxide:

the first coarse germanium dioxide and the second coarse germanium dioxide are mixed and then are subjected to hydrochloric acid distillation, rectification and hydrolysis by adopting a traditional method to obtain a high-purity germanium dioxide product meeting the requirements of GB/T11069-2017.

Second, specific application example:

A. collecting 3000g germanium-containing smoke dust containing Ge2.22%, Zn0.11%, Ca3.78%, Pb0.12%, and SiO₂69.75%、As0.056%。

B. 3000ml of ammonia water solution with the ammonia concentration of 120g/l is prepared, 1000g of germanium-containing smoke dust and the ammonia water solution are added into a reactor, 50ml of hydrogen peroxide with the concentration of 30% is added, the reactor is sealed, heating and stirring are carried out, the reaction temperature is controlled to be 50 ℃, and the reaction is continuously carried out for 3 hours under stirring. And opening the discharge valve, and pumping the material into the closed filter under negative pressure for filtering. Washing the filter residue with water.

And mixing the washing solution with the filtrate, carrying out leaching reaction with the germanium-containing smoke again, repeating the leaching for 3 times according to the conditions and the steps, and finally obtaining a first leaching residue and a first germanium solution (14.85 g/l of germanium). The leaching rate of germanium is 71.3%.

C. And adding the first germanium-containing solution into a closed evaporation tank for evaporation deamination until the solution is evaporated to dryness, taking out precipitates in the tank, washing and drying to obtain first crude germanium dioxide with the germanium content of 60.33%, and returning the washing solution to the evaporation tank for treatment. The process has substantially no loss of germanium.

The closed evaporating pot is connected with a condenser to collect the condensed ammonia solution. The ammonia solution returns to the primary cycle leaching process.

D. Adding the first leaching residue of the B and the prepared alkali leaching solution into a closed container for hot alkali oxidation leaching, wherein the secondary circulation leaching conditions are as follows:

the mixed leaching solution is medium NaOH, NaClO and Na₂CO₃The concentrations of (a) were 150g/l, 8g/l and 30g/l, respectively. BaCl₂、Fe₂(SO4)₃The adding amount is 1 percent of the first leaching residue, the liquid-solid ratio is controlled to be 3: 1, the leaching temperature is 100 ℃, and the leaching time is 5 hours.

And after the leaching reaction is finished, opening a discharge valve to a filter for filtering, adding water to filter residues for washing, combining the filtrate with a washing solution, then preparing a leaching solution again, and leaching the first leaching residue according to the conditions and the steps. This was repeated 5 times to obtain a second leaching residue and a second germanium solution (containing 6.79g/l of germanium). The leaching rate of germanium is 73.39%.

E: adding the second germanium-containing solution into a precipitation kettle, stirring, adding a magnesium salt solution prepared by magnesium sulfate, standing, filtering and washing after the reaction is finished to obtain germanium-magnesium enriched slag and a precipitated solution, and returning the precipitated solution to the secondary cycle leaching process.

The technical parameters of the control are as follows: the molar ratio of magnesium to germanium is 5: 1, the reaction temperature is 40 ℃, the mixing and stirring time is 30min, and the standing time is 60 min.

Filtering to obtain germanium-magnesium enriched slag containing 17.27% of germanium. The recovery rate of germanium is 97.46%.

F: adding the germanium-containing enriched slag into a dissolving tank, adding a sulfuric acid solution for dissolving, filtering a dissolved solution, then, entering an extractor for extraction and separation, taking saponified P204 and P507 as magnesium extractants, performing oil-water separation, performing back extraction on an organic phase by using sulfuric acid to obtain a magnesium sulfate solution containing 68g/l magnesium, concentrating, and returning to the process of magnesium salt germanium precipitation for reuse. The concentration ratio of Ge to Mg in the raffinate was 60.5: 1.

G. Adding raffinate into a precipitation tank, adding 30% liquid caustic soda for neutralizing and precipitating germanium, and filtering and drying to obtain 60.43% second crude germanium dioxide. The recovery rate of germanium is 99.06%.

H. Purifying and refining the first coarse germanium dioxide and the second coarse germanium dioxideDistilling, rectifying and hydrolyzing to obtain GeO meeting GB/T11069-₂-5 the high purity germanium dioxide product of claim.

G. The above example procedure analyzed data:

1. primary circulating leaching:

directory

Weight (D)

Ge

Zn

Ca

Pb

SiO2

As

Germanium-containing smoke

3000g

2.22%

0.11%

3.78%

0.12%

69.75%

0.056%

First germanium solution

3200ml

14.85g/l

0.33g/l

0.01 g/l

0.005 g/l

0.002 g/l

0.005 g/l

First leaching residue

2670g

0.710%

0.08%

4.22%

0.13%

78.41

0.06%

Germanium leaching rate

71.3%

33%

/

/

/

/

2. Hydrolyzing and precipitating germanium:

directory

Weight (D)

Ge

Zn

Ca

Pb

SiO2

As

First germanium solution

3200ml

14.850g/l

0.33g/l

0.01 g/l

0.005 g/l

0.002 g/l

0.005 g/l

First coarse germanium dioxide

78.75g

60.33%

1.34%

0.04%

0.02%

0.01%

0.02%

Aqueous ammonia

3180ml

Germanium recovery

99.98%

3. Secondary circulating leaching:

directory

Weight (D)

Ge

Zn

Ca

Pb

SiO2

As

First leaching residue

2670g

0.710%

0.08%

4.22%

0.13%

78.41

0.06%

Second germanium solution

2050ml

6.79g/l

0.08 g/l

0.005 g/l

0.005 g/l

0.005g/l

0.001g/l

Second leaching residue

2736g

0.18%

0.072%

Leaching rate

73.39%

4.80%

/

2.95%

/

0.08%

4. And (3) depositing germanium by using magnesium salt:

directory

Weight (D)

Ge

Zn

Ca

Pb

SiO2

As

Mg

Second germanium solution

2050ml

6.79g/l

0.08 g/l

0.005 g/l

0.005 g/l

0.005g/l

0.001g/l

/

Germanium-magnesium enriched slag

79.65g

17.27%

0.20%

0.01%

0.01%

0.05%

0.01%

22.44%

Alkaline filtrate

2400ml

0.67g/l

0.06 g/l

/

/

/

/

/

Germanium recovery

98.83%

5. Extracting and separating germanium and magnesium, neutralizing and precipitating germanium:

directory

Weight (D)

Ge

Zn

Ca

Pb

SiO2

As

Mg

Germanium-magnesium enriched slag

79.65g

17.27%

0.20%

0.01%

0.01%

0.05%

0.01%

22.44%

Second coarse germanium dioxide

22.46

60.43%

0.01%

0.01%

0.01%

0.001%

0.001%

0.99%

Liquid after germanium precipitation

700ml

0.20g/l

/

/

/

/

/

/

Magnesium salt solution

300ml

0.013g/l

0.40g/l

/

/

/

0.02g/l

59.5g/l

Germanium recovery

98.66%

6. Refining germanium dioxide:

in conclusion, the recovery rate of the germanium product is as follows: 60.78 × 999994%/(3000 × 2.22%) = 91.26%.