CN116287790A - Method for extracting germanium by solvent and preparing germanium concentrate - Google Patents

Abstract

The invention relates to the technical field of extraction of scattered metal germanium, in particular to a method for extracting germanium from hydrolyzed liquid in a Xin Guiwan-base tertiary amine-tartaric acid system and preparing germanium concentrate, which comprises the following steps: a) Mixing the feed liquid, the secondary raffinate and the acidified organic phase, and performing primary extraction; b) Mixing the primary loaded organic phase, hydrolyzed liquid and washing water phase, and performing secondary extraction; c) Mixing the secondary loaded organic phase with sodium hydroxide solution, and performing back extraction; d) Mixing the empty organic phase, sulfuric acid solution and/or acidified liquid, and performing acidification transformation; e) Mixing the back extraction liquid, the partially acidified liquid and magnesium sulfate, hydrolyzing, washing the hydrolyzed filter cake, and drying the washed filter cake to obtain germanium concentrate. The germanium concentrate germanium metal sodium hydroxide unit consumption is low, the grade is high, and the tartaric acid unit consumption is low.

Description

Method for extracting germanium by solvent and preparing germanium concentrate

Technical Field

The invention relates to a method for extracting germanium and preparing germanium concentrate from sulfate solution by adopting a octyldecyl tertiary amine-tartaric acid system, in particular to a method for extracting germanium and preparing germanium concentrate from hydrolyzed liquid for a second time, belonging to the technical field of extraction of rare-earth metal germanium.

Background

The method for extracting germanium and preparing germanium concentrate by adopting a octyldecyl tertiary amine-tartaric acid system generally comprises the steps of preparing feed liquid, extracting, back extracting and preparing back extraction liquid to prepare germanium concentrate.

The material liquid is prepared by leaching germanium-containing material with sulfuric acid solution or sulfuric acid-tartaric acid mixed solution, transferring germanium into solution, and adding or supplementing tartaric acid to form acid sulfate solution containing germanium-tartaric acid complex. The leachate is generally purified, such as gelatin flocculation desilication, reduced iron powder reduction and the like, so as to obtain feed liquid meeting the requirements of industrial continuous extraction.

The extraction is carried out by mixing feed liquid with empty organic phase, and transferring germanium tartaric acid complex into organic phase. The complexing reaction of germanium ions and tartaric acid is as follows:

Ge ⁴⁺ + 3C ₄ O ₆ H ₆ = [ Ge（C ₄ O ₆ H ₄ ） ₃ ] ²⁺ + 6H ⁺ ；

theoretically, 1mol of germanium requires 3mol of tartaric acid for complexation, that is, 1Kg of germanium requires 6.2Kg of tartaric acid for complexation.

The back extraction is to mix sodium hydroxide solution with loaded organic phase, decompose germanium tartaric acid complex and transfer germanium into water phase. In order to meet the requirement of germanium hydrolysis, the cyclic back extraction is generally carried out by using a high-content sodium hydroxide solution, and sodium hydroxide is properly supplemented in the process.

The back extraction liquid is used to prepare germanium concentrate, which is neutralized by acid solution and back extraction liquid to promote germanium hydrolysis, thus obtaining germanium concentrate.

Chinese patent CN 1020711C discloses a method for recovering germanium from germanium-containing acidic solution, using organic phase containing 3% (volume percentage) of tri Xin Guiwan group tertiary amine, extracting germanium from acidic aqueous solution whose PH is regulated to 0.8-1.3 by sulfuric acid, adding at least 2.15kg tartaric acid to each kg of germanium in acidic aqueous solution for complexation, loading organic phase containing 0.45 g/L-1.5 g/L of germanium, washing with fresh water, stripping the washed organic phase with 4.5N-5.0N sodium hydroxide solution, regulating PH 8-11 by adding sulfuric acid into stripping solution, hydrolyzing and filtering at 70-80 ℃ to obtain precipitate, washing water and hydrolyzed solution containing tartaric acid, and back-extracting to implement cyclic use of more than 75% of tartaric acid, and returning the unloaded organic phase for extraction. However, the method has low extractant concentration, high organic phase load, large Vo/Va compared with washing and back extraction, difficult realization of continuous extraction production, inconsistent tartaric acid consumption and sodium hydroxide consumption with production practice, and failure to provide the grade of precipitated germanium metal and the recovery rate of germanium.

Chinese patent CN 101538653B discloses a process for preparing germanium concentrate from germanium-containing industrial liquor, which comprises extracting germanium from germanium-containing industrial liquor with pH value of 0.5-3 by using organic phase containing 20-30% of tetraalkylamine or trialkylamine, adding 3.0-10.0 kg complexing agent per kg germanium in germanium-containing industrial liquor, stripping loaded organic phase by using 5-30% sodium hydroxide or sodium carbonate solution, regulating pH of the stripping liquor by using acid to make secondary hydrolysis, using Mg ²⁺ And (3) taking the plasma metal ions as a secondary hydrolysis sedimentation assisting agent, returning the secondary sediment to primary hydrolysis to produce germanium concentrate with the grade of 11.5%, and recovering the complexing agent from the hydrolysis residual liquid by a crystallization method. However, the complexing agents comprise citric acid, citrate, tartaric acid and tartrate, the recovery method by crystallization method is not fully described, the recovery method is not returned to the system for use, the consumption of sodium hydroxide is not clear, and the grade of germanium concentrate is low.

Chinese patent CN 1020711C indicates that Xin Guiwan-group tertiary amine-tartaric acid system extracts germanium, and only a certain amount of ions can be extracted, only bisulfate ions [ HSO ₄ ^- ]While Chinese patent CN 101538653B indicates that the feed liquid contains Cl ^- 0.56g/L Cl in the raffinate after extraction ^- 160mg/L or less, there is a clear contradiction between the two.

Chinese patent CN 109929997B discloses a method for producing germanium concentrate by using N235 extractant, extracting germanium from germanium-containing acid solution by using N235-containing organic phase, adding 3.0 kg-5.0 kg of organic complex into each kg of germanium in the germanium-containing acid solution, washing loaded organic phase by using organic acid solution corresponding to 0.1% -5% of organic complex, circularly stripping the washed loaded organic phase with sodium hydroxide solution for several times until the germanium content of strip liquor is above 20g/L, regulating PH of strip liquor by using sulfuric acid to 9-11 for hydrolysis, washing and calcining hydrolysis filter cake to obtain 30% -50% germanium dioxide concentrate, using calcium hydroxide or calcium oxide to causticize hydrolysis filtrate, producing sodium hydroxide solution for return use, and producing calcium-containing precipitate and then using organic complexing agent for return use. The method ensures the extraction rate of germanium, greatly reduces the consumption of sodium hydroxide, improves the grade of germanium concentrate, regenerates and recovers the organic complexing agent of sodium hydroxide and germanium, reduces the environmental treatment cost of waste residue and wastewater, and has good economic benefit and environmental benefit. However, the method uses calcium hydroxide or calcium oxide to causticize sodium sulfate solution, the causticizing efficiency is low, the recovery of the organic complexing agent increases the leaching of calcium-containing precipitate, and the process flow is complicated.

Obviously, improving the grade of germanium concentrate, reducing the unit consumption of germanium metal complexing agent and reducing the unit consumption of germanium metal sodium hydroxide is a core task in a Xin Guiwan-based tertiary amine-tartaric acid system germanium extraction and germanium concentrate preparation method.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a method for extracting germanium and preparing germanium concentrate by using a Xin Guiwan-base tertiary amine-tartaric acid system, wherein the unit consumption of germanium metal sodium hydroxide is low, the grade of germanium metal in germanium concentrate is high, and the unit consumption of germanium metal tartaric acid is low.

The technical scheme of the invention is as follows: a method for solvent extracting germanium and preparing germanium concentrate, comprising the following steps:

mixing a feed liquid, a secondary raffinate and an acidified organic phase, performing primary extraction to obtain a primary raffinate and a primary loaded organic phase, wherein the feed liquid is a sulfate solution of a germanium-containing tartaric acid complex, the secondary raffinate contains complexing agent tartaric acid, the acidified organic phase contains extractant three Xin Guiwan-group tertiary amine, and the primary raffinate is used for recycling other metals;

mixing the primary loaded organic phase, hydrolyzed liquid and washing water phase produced in the step A, and carrying out secondary extraction to produce secondary raffinate and a secondary loaded organic phase, wherein the hydrolyzed liquid and washing water contain complexing agent tartaric acid, and the secondary raffinate is returned to the step A for use;

mixing the secondary loaded organic phase produced in the step B with sodium hydroxide solution, and carrying out back extraction to produce an empty organic phase and a back extraction liquid;

mixing the unloaded organic phase, sulfuric acid solution and/or acidified liquid produced in the step C, and carrying out acidification and inversion to produce an acidified organic phase and acidified liquid, wherein the acidified organic phase is returned to the step A for use, and part of the acidified liquid is returned to the step for use;

e) Mixing the strip liquor produced in the step C, the partially acidified liquor produced in the step D and magnesium sulfate, hydrolyzing to produce hydrolyzed liquor and hydrolyzed filter cakes, washing the hydrolyzed filter cakes with fresh water to produce washed filter cakes and washing water, returning the hydrolyzed liquor and washing water containing complexing agent tartaric acid to the step B for use, and drying the washed filter cakes to produce germanium concentrate.

Xin Guiwan-base tertiary amine extractant is a broad-spectrum anion extractant, and small amount of chloride ions exist in sulfate solution to form complex anions of zinc, cadmium, bismuth, antimony, tin, lead and the like, so that the complex anions are easily extracted into an organic phase by Xin Guiwan-base tertiary amine extractant, and the concentration of impurity metal ions in a loaded organic phase is improved. Preferably, the feed liquid in the step A is subjected to dechlorination pretreatment, and the mass and volume concentration of chloride ions is less than 0.2g/L.

The extraction process of the Xin Guiwan tertiary amine extractant on the metal complex anions is an anion exchange process. To achieve this exchange, the Xin Guiwan-based tertiary amine extractant is acid treated to extract the acid to form an amine salt. The exchange of anions occurs when the organic phase containing the amine salt is contacted with an aqueous solution containing metal complex anions. Obviously, the concentration of amine salt is high, the anion exchange reaction efficiency is high, however, the higher the concentration of amine salt in the loaded organic phase is, the larger the consumption of alkali in back extraction is, and the back extraction liquid is crystallized.

In practice, it is further preferred that the ratio of the amount concentration of trioctyldecyl tertiary amine species as extractant in the acidified organic phase to the amount concentration of germanium species in the feed solution in step A is from 22 to 24:1.

In the case of complete stripping, in order to fully utilize sodium hydroxide in the stripping agent, it is still further preferable that the stripping in the step C is a secondary countercurrent stripping, the secondary loaded organic phase is mixed with the secondary stripping solution to perform primary stripping, the primary stripping solution is produced as the stripping solution, 2.0 g/L-5.0 g/L of free sodium hydroxide is contained, the primary stripping organic phase is produced, and the sodium hydroxide solution is mixed to perform secondary stripping, and the secondary stripping organic phase is produced as the empty loaded organic phase.

And D, adding the partially acidified solution produced in the step D into the back extraction solution produced in the step C, adjusting the PH to be 9-10, and then adding magnesium sulfate for mixed hydrolysis.

More preferably, the magnesium sulfate is used in an amount of 5 to 7 times the weight of germanium in the solution.

In the step E, the washing filter cake contains impurities such as magnesium tartrate, and organic matters are preferably thermally decomposed to improve the grade of germanium concentrate.

Further preferably, the drying temperature of the washed cake is 250 to 300 ℃.

The hydrolysis filtrate and wash water contained not only the major portion of tartaric acid extracted into the organic phase, but also germanium ions that failed to hydrolyse the precipitate and a small amount of free sodium hydroxide. The hydrolysis filtrate is mixed with washing water and the primary load organic phase for secondary extraction, so that the primary load organic phase is washed, partial impurity ions are removed, the primary load organic phase is partially neutralized, and the added sodium hydroxide is fully utilized. The secondary raffinate returns to primary extraction, so that the unit consumption of complexing agent tartaric acid can be obviously reduced. In addition, germanium in the hydrolysis filtrate and the washing water is extracted into the organic phase again, so that the saturated extraction of the organic phase is realized, and the germanium content and purity of the secondary load organic phase are improved.

Preferably, the phase ratio of the secondary extraction in step B is Vo/va=10:3 to 4.

The invention has the beneficial effects that:

the unit consumption of germanium metal sodium hydroxide in germanium concentrate is low: the method adopts the octyldecyl tertiary amine-tartaric acid system to extract germanium and prepare germanium concentrate, and sodium hydroxide is mainly consumed in the following two aspects: a) Decomposing germanium tartaric acid complex anions in the loaded organic phase; b) Other metal complex anions in the loaded organic phase are decomposed. Compared with the prior art, the invention adopts the method for removing the sulfate solution containing germanium tartaric acid complex anionsChlorine pretreatment, namely reducing the concentration of chlorine complex anions in the loaded organic phase, and further reducing the consumption of sodium hydroxide; the concentration ratio of the octyldecyl tertiary amine in the organic phase to the germanium tartaric acid complex anions in the feed liquid is strictly controlled, and the hydrogen sulfate ion [ HSO ] in the loaded organic phase is reduced ^4- ]Further reducing the sodium hydroxide unit consumption; the hydrolysis filtrate and the washing water are mixed with the primary loaded organic phase to carry out secondary extraction, so that the primary loaded organic phase is pre-neutralized, and the concentration and purity of germanium complex anions in the secondary loaded organic phase are improved, thereby reducing the consumption of sodium hydroxide; and the concentration of free sodium hydroxide in the primary stripping liquid is strictly controlled by implementing two-stage stripping, namely, the direct hydrolysis of organic phase loaded metal ions is implemented, so that the surplus of free sodium hydroxide in the primary stripping liquid is avoided, and the consumption of sodium hydroxide is reduced.

Germanium concentrate germanium metal grade is high: the germanium metal grade of the germanium concentrate is improved, and the essence is to improve the content of germanium metal and reduce the content of impurity metal. Compared with the prior art, the method has the advantages that the dechlorination pretreatment is carried out on the feed liquid, the concentration of the tertiary Xin Guiwan tertiary amine in the organic phase is strictly controlled, the hydrolysis filtrate and the washing water are adopted to carry out the preneutralization washing extraction on the primary loaded organic phase, the method is beneficial to improving the germanium metal grade of germanium concentrate, and the magnesium sulfate dosage of the stripping liquid sedimentation assisting agent is strictly controlled, so that the hydrolysis sedimentation rate of germanium in the stripping liquid is ensured, the germanium metal grade of germanium concentrate is also beneficial to being ensured, the magnesium tartrate contained in the washing filter cake is decomposed by controlling the temperature in the drying process, and the germanium metal grade of germanium concentrate is improved.

Germanium concentrate germanium metal complexing agent tartaric acid unit consumption low germanium and tartaric acid forming complex anions [ Ge (C) ₄ O ₆ H4) ₃ ] ^2- The ratio of the substances is 1:3, 6.20kg of tartaric acid is theoretically needed for complexing each kilogram of germanium, the recovery of the tartaric acid serving as a complexing agent is generally concerned, and three methods are mainly adopted: the hydrolysis filtrate is directly returned; crystallizing the hydrolyzed filtrate and returning; the hydrolyzed filtrate is returned after being treated. Compared with the prior art, the complexing agent exists in the secondary raffinate, and the complexing agent is directly extracted back, so that the disposal measures are simple and easy, the direct yield of germanium is ensured, the liquid germanium metal after hydrolysis is prevented from entering the extraction large circulation, and the reduction is greatly realizedThe consumption of the complexing agent tartaric acid is reduced.

Drawings

Fig. 1 is a process flow diagram of a method for preparing germanium concentrate by solvent extraction.

Description of the embodiments

The following detailed description of the invention is presented in conjunction with the drawings and preferred embodiments to enable one skilled in the art to practice the objects of the invention, but the claims of the invention are not limited to the description and the preferred embodiments.

As shown in figure 1, the invention relates to a method for extracting germanium and preparing germanium concentrate from sulfate solution by adopting a octyldecyl tertiary amine-tartaric acid system, which comprises the steps of primary extraction, secondary extraction, back extraction, acidification, hydrolysis, washing and drying.

The feed liquid is a sulfate solution of germanium-containing tartaric acid complex, and can be generally prepared by leaching germanium-containing materials with sulfuric acid solution or sulfuric acid-tartaric acid mixed solution, and adding or supplementing tartaric acid to form a sulfate solution of germanium-containing tartaric acid complex. In order to meet the requirements of industrial continuous extraction, the leaching solution can be subjected to gelatin flocculation desilication, reduced iron powder reduction impurity removal treatment and the like. The invention relates to a decylalkyl tertiary amine as a broad-spectrum extractant, wherein the extraction process is an anion or metal complex anion exchange process, and the dechlorination pretreatment is carried out on feed liquid to ensure that the mass volume concentration of chloride ions is less than 0.2g/L in order to reduce the content of metal chloride complex anions in a loaded organic phase. Measures for dechlorination pretreatment include, but are not limited to, ion exchange, extraction and cuprous salt precipitation.

The organic phase contains trioctyldecyl tertiary amine as extractant, sec-octanol or tributyl phosphate as modifier and No. 260 solvent oil. Clearly, the larger the concentration ratio, the more advantageous the germanium extraction, but at the same time the higher the hydrogen sulphate ion content in the loaded organic phase. Through practical optimization, the concentration ratio is preferably 22-24:1.

Firstly, mixing feed liquid and an acidified organic phase, and performing primary extraction to produce primary raffinate and a primary loaded organic phase, wherein the primary raffinate is used for recycling other metals; then, mixing the primary loaded organic phase with tartaric acid solution phase, performing secondary extraction to produce secondary raffinate and a secondary loaded organic phase, and mixing the secondary raffinate with feed liquid for primary extraction; then, mixing the secondary loaded organic phase with sodium hydroxide solution, and carrying out back extraction to obtain an empty organic phase and a back extraction liquid; mixing the empty organic phase with sulfuric acid solution, carrying out acidification and inversion to produce an acidified organic phase and acidified liquid, returning the acidified organic phase to primary extraction for use, and returning part of the acidified liquid to recycle; and finally, mixing the back extraction liquid, the partially acidified liquid and magnesium sulfate, hydrolyzing to produce hydrolyzed liquid and hydrolyzed filter cake, washing the hydrolyzed filter cake with new water to produce washed filter cake and washing water, returning the hydrolyzed liquid and washing water containing complexing agent tartaric acid to secondary extraction to replace tartaric acid solution for use, and drying the washed filter cake to produce germanium concentrate.

Selecting germanium-containing zinc oxide powder from certain company and sulfuric acid solution to make two-stage countercurrent leaching to obtain leaching solution, adding bone glue into the leaching solution to flocculate and desilice, adding reduced iron powder into the desilication solution to reduce copper and ferric ions to obtain purifying solution containing Zn ²⁺ 110.5g/L、 Mn ²⁺ 21.1g/L、Fe ³⁺ 0.020g/L、 Fe ²⁺ 3.25g/L、 Cd ²⁺ 3.28g/L、 Ge ⁴⁺ 1.20g/L、Ni ²⁺ 0.045g/L、Co ²⁺ 0.008g/L、 Cu ²⁺ Undetected, F ^- 0.080g/L、CL ^- 3.15g/L、T _AS 0.12g/L、 Sb 0.010g/L、SiO ₂ 0.045g/L、H ₂ SO ₄ 17.8g/L。

Comparative example 1:

the mass concentration of germanium in the purifying liquid is 0.0165mol/L, and the ratio of the mass concentration of trioctyldecyl tertiary amine serving as an extractant in the organic phase to the mass concentration of germanium in the liquid is 15:1 an organic phase containing trioctyldecyl tertiary amine was formulated. The newly prepared organic phase and 100g/L sulfuric acid solution are mixed for 10 minutes according to the ratio Vo/Va=2:1, and the mixture is stood for layering, so that an upper acidified organic phase is obtained, and the loaded organic phase contains 24.0g/L of bisulfate ions.

Taking 10.0L of purified liquid, adding 72.0g of tartaric acid, uniformly mixing to obtain a sulfate solution of a germanium-containing tartaric acid complex, namely a feed liquid, extracting the sulfate solution with 5.0L of acidified organic phase in a small three-stage countercurrent mixing clarifier, and standing for 10 minutes at the temperature of 30-35 ℃ for 10 minutes to obtain raffinate, wherein the raffinate contains Zn, compared with Vo/Va=1:2 ²⁺ 109.3g/L、 Mn ²⁺ 21.1g/L、Fe ³⁺ 0.020g/L、 Fe ²⁺ 3.25g/L、 Cd ²⁺ 1.23g/L、 Ge ⁴⁺ 0.542g/L、Ni ²⁺ 0.045g/L、Co ²⁺ 0.008g/L、 Cu ^{2 +} Undetected, F ^- 0.080g/L、CL ^- 0.21g/L、T _AS 0.12g/L、 Sb 0.010g/L、SiO ₂ 0.045g/L、H ₂ SO ₄ The extraction rates of zinc, cadmium, germanium, chlorine and tartaric acid are 1.08%, 62.50%, 54.83%, 93.33% and 99.86% respectively, and the concentration of zinc, cadmium, germanium, chlorine, hydrogen sulfate ions and tartaric acid in the loaded organic phase is 2.4g/L, 4.1g/L, 1.316g/L, 5.88g/L, 19.20g/L and 14.38g/L respectively.

Comparative example 2:

the mass concentration of germanium in the purifying liquid is 0.0165mol/L, and the ratio of the mass concentration of trioctyldecyl tertiary amine serving as an extractant in the organic phase to the mass concentration of germanium in the liquid is 30:1 an organic phase containing trioctyldecyl tertiary amine was formulated. The newly prepared organic phase and 100g/L sulfuric acid solution are mixed for 10 minutes according to the ratio Vo/Va=2:1, and the mixture is stood for layering, so that an upper acidified organic phase is obtained, and the loaded organic phase contains 48.02g/L of bisulfate ions.

Taking 10.0L of purified liquid, adding 72.0g of tartaric acid, uniformly mixing to obtain a sulfate solution of a germanium-containing tartaric acid complex, namely a feed liquid, extracting the sulfate solution with 5.0L of acidified organic phase in a small three-stage countercurrent mixing clarifier, and standing for 10 minutes at the temperature of 30-35 ℃ for 10 minutes to obtain raffinate, wherein the raffinate contains Zn, compared with Vo/Va=1:2 ²⁺ 108.6g/L、 Mn ²⁺ 21.1g/L、Fe ³⁺ 0.020g/L、 Fe ²⁺ 3.25g/L、 Cd ²⁺ 0.25g/L、 Ge ⁴⁺ 0.007g/L、Ni ²⁺ 0.045g/L、Co ²⁺ 0.008g/L、 Cu ^{2 +} Undetected, F ^- 0.080g/L、CL ^- 0.16g/L、T _AS 0.12g/L、 Sb 0.010g/L、SiO ₂ 0.045g/L、H ₂ SO ₄ 26.30g/L and 0.010g/L tartaric acid, wherein the extraction rates of zinc, cadmium, germanium, chlorine and tartaric acid are respectively 1.72%, 92.37%, 99.42%, 94.92% and 99.86%, and the concentration of zinc, cadmium, germanium, chlorine, bisulfate ions and tartaric acid in the loaded organic phase are respectively 3.80g/L, 6.06g/L, 2.386g/L, 5.98g/L, 31.02g/L and 14.38g/L.

Comparative example 3:

the control 1 and the control 2 are combined to obtain 10.0L of mixed load organic phase, the concentration of zinc, cadmium, germanium, chlorine, hydrogen sulfate ions and tartaric acid is respectively 3.10g/L, 5.06g/L, 1.848g/L, 5.93g/L, 25.11g/L and 14.38g/L, the mixed load organic phase and the 5.0L of fresh water are extracted in a small-sized secondary countercurrent mixing clarifier, compared with Vo/Va=2:1, the temperature is 30-35 ℃, the mixing time is 10 minutes, and the mixture is kept stand for 10 minutes to obtain washing water containing Zn ²⁺ 1.64g/L、 Cd ²⁺ 0.07g/L、 Ge ⁴⁺ 0.015g/L、CL ^- 1.01g/L、H ₂ SO ₄ The elution rates of zinc, cadmium, germanium, chlorine, bisulfate ions and tartaric acid were 26.45%, 0.69%, 0.40%, 8.52%, 6.49% and 0.32%, respectively, and the concentrations of zinc, cadmium, germanium, chlorine, bisulfate ions and tartaric acid in the loaded organic phase were 2.28g/L, 5.02g/L, 1.84g/L, 5.42g/L, 23.48g/L and 14.33g/L, respectively, at 3.26g/L, 0.093g/L, tartaric acid.

Washing the loaded organic phase 2.0L and mixing with 1.0L200g/L sodium hydroxide solution for back extraction, comparing Vo/Va=2:1, the temperature is 30-35 ℃ and the mixing time is 10 minutes, standing for 10 minutes to obtain a back extraction liquid, precipitating the back extraction liquid, and vacuum filtering to obtain filtrate containing Zn ²⁺ 4.54g/L、 Cd ²⁺ 0.03g/L、 Ge ⁴⁺ 3.67g/L、CL ^- The stripping rates of zinc, germanium, chlorine, hydrogen sulfate ion and tartaric acid are respectively 99.56%, 99.73%, 99.91%, 99.98% and 99.96%, the concentration of zinc, germanium, chlorine, hydrogen sulfate ion and tartaric acid in the loaded organic phase is respectively 0.01g/L, 0.005g/L and 0.005g/L, and cadmium is insoluble in sodium hydroxide solution and is a main precipitation component, and the concentration of zinc, germanium, chlorine, hydrogen sulfate ion and tartaric acid in the loaded organic phase is not measured or countedCalculating the cadmium back extraction rate and the concentration of the empty organic phase, supplementing 60.0g of sodium hydroxide to the back extraction filtrate, mixing the back extraction filtrate with 2.0L of washing load organic phase, back extracting, repeating the operation for 3 times, consuming 380.0g of accumulated sodium hydroxide to obtain 1.0L of back extraction filtrate containing Zn ²⁺ 22.70g/L、 Cd ²⁺ 0.06g/L、 Ge ⁴⁺ 18.35g/L、CL ^- 54.15g/L, naOH g/L140.0 g/L, 234.75g/L sulfate ion and 143.0g/L tartaric acid.

Taking 1.0L of back extraction filtrate, dropwise adding 92.0mL (about 170.0 g) of concentrated sulfuric acid under stirring to regulate pH9.0, heating to 75 ℃, reacting for 2.0 hours at a constant temperature, and vacuum filtering to obtain 87.6g of filter cake, thereby obtaining 1.0L of filtrate containing Zn ²⁺ 0.80g/L、 Cd ²⁺ 0.06g/L、 Ge ⁴⁺ 8.54g/L、CL ^- 54.15g/L, 143.0g/L tartaric acid, and 53.46 percent of germanium hydrolysis precipitation rate. Taking 1.0L of filtrate, adding 60.0g of magnesium sulfate heptahydrate according to 7 times of germanium amount under stirring, heating to 75 ℃, preserving heat, reacting for 2.0 hours, vacuum filtering to obtain 240.0g of filter cake, obtaining 1.0L of filtrate containing Zn ²⁺ 0.35g/L、 Cd ²⁺ 0.05g/L、 Ge ⁴⁺ 3.48g/L、CL ^- 47.4g/L, 124.9g/L tartaric acid, 59.25 percent of germanium hydrolysis precipitation rate and 12.66 percent of tartaric acid precipitation rate. Mixing 327.6g of twice hydrolyzed filter cakes, adding 1.0L of fresh water, mixing, stirring and washing for 1.0 hour at 75 ℃, vacuum filtering to obtain 262.4g of washed filter cakes, drying at 250 ℃ to obtain 131.2g of germanium concentrate, 11.23% of germanium, 14.73g of folded germanium metal, 1.0L of washing filtrate and 1.0L of Ge-containing germanium ⁴⁺ 0.14g/L, 2.34g/L tartaric acid, 0.94 percent of germanium elution and 12.93 percent of tartaric acid elution. The accumulated germanium hydrolysis precipitation rate is 80.82 percent, the tartaric acid recovery rate is 88.98 percent, and the unit consumption of germanium metal sodium hydroxide of germanium concentrate is 25.55g NaOH/gGe.

Examples

The mass concentration of germanium in the purifying liquid is 0.0165mol/L, and the ratio of the mass concentration of trioctyldecyl tertiary amine serving as an extractant in the organic phase to the mass concentration of germanium in the liquid is 22:1 an organic phase containing trioctyldecyl tertiary amine was formulated. Mixing the newly prepared organic phase with 100g/L sulfuric acid solution according to the ratio Vo/Va=2:1 for 10 minutes, standing and layering to obtain an upper acidified organic phase and acidified liquid, wherein the loaded organic phase contains 35.2g/L of bisulfate ions.

Taking a purifying liquid 1Dechlorination is carried out on 0.0L by macroporous strong base ion exchange resin to obtain an adsorbed liquid containing Cl ^- 0.19g/L. Adding 72.0g of tartaric acid into the adsorbed solution, uniformly mixing to obtain a sulfate solution of a germanium-containing tartaric acid complex, namely a feed liquid, extracting the sulfate solution and 5.0L of acidified organic phase in a small three-stage countercurrent mixer-settler, and standing for 10 minutes at 30-35 ℃ for 10 minutes at a temperature of 30-35 ℃ to obtain raffinate containing Zn, wherein Vo/Va=1:2 ²⁺ 110.2g/L、 Mn ²⁺ 21.1g/L、Fe ³⁺ 0.020g/L、 Fe ²⁺ 3.25g/L、 Cd ²⁺ 2.78g/L、 Ge ⁴⁺ 0.005g/L、Ni ²⁺ 0.045g/L、Co ²⁺ 0.008g/L、 Cu ²⁺ Undetected, F ^- 0.080g/L、CL ^- Go undetected, T _AS 0.12g/L、 Sb 0.010g/L、SiO ₂ 0.045g/L、H ₂ SO ₄ The extraction rates of zinc, cadmium, germanium, chlorine and tartaric acid are respectively 0.27%, 15.24%, 99.58%, 100% and 99.86%, and the concentration of zinc, cadmium, germanium, chlorine, bisulfate ions and tartaric acid in the loaded organic phase are respectively 0.6g/L, 1.0g/L, 2.39g/L, 0.4g/L, 25.2g/L and 14.38g/L.

Examples

The mass concentration of germanium in the purifying liquid is 0.0165mol/L, and the ratio of the mass concentration of trioctyldecyl tertiary amine serving as an extractant in the organic phase to the mass concentration of germanium in the liquid is 24:1 an organic phase containing trioctyldecyl tertiary amine was formulated. The acidified solution of example 1 was supplemented with sulfuric acid to 100g/L free sulfuric acid, mixed with a freshly prepared organic phase for 10 minutes according to Vo/va=2:1, allowed to stand for delamination to obtain an upper acidified organic phase and an acidified solution, and the loaded organic phase contained 38.4g/L bisulfate ions.

Taking 10.0L of purified liquid, extracting and dechlorinating the purified liquid by using an amine extractant solvent to obtain raffinate containing Cl ^- 0.16g/L. Adding 72.0g of tartaric acid into the raffinate, uniformly mixing to obtain a sulfate solution of germanium-containing tartaric acid complex, namely a feed liquid, extracting the sulfate solution and 5.0L of acidified organic phase in a small three-stage countercurrent mixing clarifier, wherein the temperature is 30-35 ℃ and the mixing time is 10 minutes compared with Vo/Va=1:2, and standing for 10 minutes to obtain raffinate containing Zn ²⁺ 110.2g/L、 Mn ²⁺ 21.1g/L、Fe ³⁺ 0.020g/L、 Fe ²⁺ 3.25g/L、 Cd ²⁺ 2.78g/L、 Ge ⁴⁺ 0.002g/L、Ni ²⁺ 0.045g/L、Co ²⁺ 0.008g/L、 Cu ²⁺ Undetected, F ^- 0.080g/L、CL ^- Go undetected, T _AS 0.12g/L、 Sb 0.010g/L、SiO ₂ 0.045g/L、H ₂ SO ₄ The extraction rates of zinc, cadmium, germanium, chlorine and tartaric acid are respectively 0.27%, 15.24%, 99.83%, 100% and 99.86%, and the concentration of zinc, cadmium, germanium, chlorine, bisulfate ions and tartaric acid in the loaded organic phase are respectively 0.6g/L, 1.0g/L, 2.40g/L, 0.32g/L, 25.8g/L and 14.38g/L.

Examples

10.0L of mixed load organic phase is obtained by combining the example 1 and the example 2, the concentration of zinc, cadmium, germanium, chlorine, hydrogen sulfate ions and tartaric acid is respectively 0.6g/L, 1.0g/L, 2.40g/L, 0.36g/L, 25.50g/L and 14.38g/L, and the mixed load organic phase is extracted in a small-sized two-stage countercurrent mixing clarifier with 5.0L of 40.0g/L tartaric acid solution, compared with Vo/Va=2:1, the temperature is 30-35 ℃, the mixing time is 10 minutes, the washing water is obtained after standing for 10 minutes, and the Zn-containing washing water is obtained ²⁺ 0.72g/L、 Cd ²⁺ 0.07g/L、 Ge ⁴⁺ 0.015g/L、CL ^- 0.36g/L、H ₂ SO ₄ 3.26g/L, 41.26g/L tartaric acid, and zinc, cadmium, germanium, chlorine and bisulfate ions elution rates of 60.0%, 3.50%, 0.31%, 50.0% and 6.39%, respectively, and concentrations of zinc, cadmium, germanium, chlorine, bisulfate ions and tartaric acid in the loaded organic phase of 0.24g/L, 0.965g/L, 2.39g/L, 0.18g/L, 23.87g/L and 13.75g/L, respectively.

The organic phase with washing load is mixed with 0.4L of 80.0g/L sodium hydroxide solution for back extraction, and the organic phase is directly hydrolyzed, compared with Vo/Va=5:1, the temperature is 30-35 ℃, the mixing time is 10 minutes, and the back extraction liquid is obtained after standing for 10 minutes, and is a suspension with precipitation, and the back extraction liquid contains 5.38g/L germanium, 5.0g/L free sodium hydroxide and 61.88g/L tartaric acid. The organic phase is regenerated by mixing and back-extracting the primary back-extracted organic phase with 0.4L of 80.0g/L sodium hydroxide solution, the temperature is 30-35 ℃ and the mixing time is 10 minutes compared with Vo/Va=5:1, and the secondary back-extracted liquid and the empty organic phase are obtained after standing for 10 minutes, wherein the secondary back-extracted liquid is a clear solution, and contains 0.75g/L germanium, 78.4g/L free sodium hydroxide and 6.86g/L tartaric acid. This operation was repeated to run out 10L of the wash load organic phase, yielding 2.0L of the primary stripping suspension and 0.4L of the secondary stripping solution, which consumed 160.0g of sodium hydroxide, recovered 134.8g of tartaric acid, and recovered 98.04%.

Taking 2.0L of primary back extraction suspension, adding the acidized solution obtained in the embodiment 2 under stirring, regulating the pH value to 9.0, heating to 75 ℃, adding 53.8g of magnesium sulfate heptahydrate according to 5 times of the germanium amount, reacting for 1.5 hours under heat preservation, and carrying out vacuum suction filtration to obtain 215.6 g of hydrolysis filter cake, thereby obtaining 2.0L of hydrolysis filtrate, 2.38g/L of germanium and 51.2g/L of tartaric acid. Adding 1.0L of fresh water into the hydrolyzed filter cake, stirring and washing for 1.0 hour at 75 ℃, and carrying out vacuum suction filtration to obtain 188.2g of water-washed filter cake, wherein the water-washed filter cake is 1.0L, and the germanium content is 0.45g/L and the tartaric acid content is 7.5g/L.

The water washed filter cake was dried at 250℃to give 74.56g of milky white powder, 24.66 g of germanium, which was 18.39g of germanium metal. And the germanium metal direct recovery rate of the germanium concentrate is 76.65 percent by the amount of germanium in the loaded organic phase, and the unit consumption of the germanium metal sodium hydroxide of the germanium concentrate is 8.70g/g.

Example 4:

taking an empty organic phase containing an extractant, namely octyl decyl tertiary amine in example 3, wherein the mass concentration of germanium in the purifying liquid is 0.0165mol/L, and the ratio of the mass concentration of the extractant, namely trioctyldecyl tertiary amine in the organic phase to the mass concentration of germanium in the liquid is 23:1. example 2 the acidified solution was adjusted with sulfuric acid to 100g/L sulfuric acid solution, mixed with the empty organic phase for 10 minutes according to Vo/va=2:1, and allowed to stand for demixing to give the upper acidified organic phase, which contained 36.8g/L bisulfate ions.

Taking 20.0L of purified solution, dechlorinating by a cuprous salt precipitation method to obtain dechlorinated solution, wherein the solution contains Cl ^- 0.18g/L. 144.0g of tartaric acid is added into the dechlorinated liquid, the mixture is uniformly mixed to obtain a sulfate solution of germanium-containing tartaric acid complex, namely a feed liquid, the sulfate solution and 10.0L of acidified organic phase are subjected to primary extraction in a small three-stage countercurrent mixer-settler, and compared with Vo/Va=1:2, the temperature is 30-35 ℃ and the mixing time is 10 minutes, and the mixture is kept stand for 10 minutes to obtain primary raffinate containing Zn ²⁺ 110.2g/L、 Mn ²⁺ 21.1g/L、Fe ³⁺ 0.020g/L、 Fe ²⁺ 3.25g/L、 Cd ²⁺ 2.78g/L、 Ge ⁴⁺ 0.005g/L、Ni ²⁺ 0.045g/L、Co ²⁺ 0.008g/L、 Cu ²⁺ Undetected, F ^- 0.080g/L、CL ^- Go undetected, T _AS 0.12g/L、 Sb 0.010g/L、SiO ₂ 0.045g/L、H ₂ SO ₄ The extraction rates of zinc, cadmium, germanium, chlorine and tartaric acid are respectively 0.27%, 15.24%, 99.58%, 100% and 99.86%, and the concentration of zinc, cadmium, germanium, chlorine, hydrogen sulfate ions and tartaric acid in the primary loaded organic phase are respectively 0.6g/L, 1.0g/L, 2.39g/L, 0.4g/L, 25.4g/L and 14.38g/L.

Mixing the hydrolysis filtrate and washing water in example 3 to obtain 3.0L mixed solution, carrying out secondary extraction on 1.737g/L germanium-containing and 36.63g/L tartaric acid and 10.0L primary loaded organic phase in a small secondary countercurrent mixer-settler, and standing for 10 minutes at 30-35 ℃ for 10 minutes at the temperature of 30-35 ℃ to obtain secondary raffinate containing Ge, wherein Vo/Va=10:3 ⁴⁺ The extraction rates of germanium and tartaric acid are respectively 93.09 percent and 14.11 percent, and the concentration of germanium and tartaric acid in the secondary load organic phase is respectively 2.93g/L and 16.10g/L.

Mixing 2.0L of the secondary loaded organic phase with 0.4L of 80.0g/L sodium hydroxide solution for back extraction, and directly hydrolyzing the organic phase, wherein the temperature is 30-35 ℃ for 10 minutes compared with Vo/Va=5:1, and standing for 10 minutes to obtain a back extraction liquid, wherein the back extraction liquid is a suspension with precipitation, and contains 5.18g/L germanium, 2.0g/L free sodium hydroxide and 73.82g/L tartaric acid. The organic phase is regenerated by mixing and back-extracting the primary back-extracted organic phase with 0.4L of 80.0g/L sodium hydroxide solution, the temperature is 30-35 ℃ and the mixing time is 10 minutes compared with Vo/Va=5:1, and the secondary back-extracted liquid and the empty organic phase are obtained after standing for 10 minutes, wherein the secondary back-extracted liquid is a clear solution, and contains 0.68g/L germanium, 78.2g/L free sodium hydroxide and 6.66g/L tartaric acid. This operation was repeated, using up 10L of the wash load organic phase, yielding 2.0L of the primary stripping suspension and 0.4L of the secondary stripping solution, which consumed 160.0g of sodium hydroxide, 158.3g of tartaric acid recovered, and a recovery rate of 98.32%.

Taking 2.0L of primary back extraction suspension, adding acidified solution to adjust the pH value to 9.0 under stirring, heating to 75 ℃, adding 36.3g of magnesium sulfate heptahydrate according to 7 times of the germanium amount, reacting for 1.5 hours under heat preservation, and vacuum filtering to obtain 262.3g of hydrolysis filter cake, and obtaining 2.0L of hydrolysis filtrate, 2.48g/L of germanium and 54.41g/L of tartaric acid. Adding 1.0L of fresh water into the hydrolyzed filter cake, stirring and washing for 1.0 hour at 75 ℃, and carrying out vacuum suction filtration to obtain 209.5g of water-washed filter cake, thereby obtaining 1.0L of water-washed cake, 0.52g/L of germanium-containing and 8.34g/L of tartaric acid.

The water washed filter cake was dried at 300℃to give 94.41g of milky white powder, 25.23 g of germanium, and 23.82g of reduced germanium metal. And the germanium metal recovery rate of the germanium concentrate is 81.30 percent based on the germanium amount of the loaded organic phase, and the unit consumption of the germanium metal sodium hydroxide of the germanium concentrate is 6.72g/g.

Examples

Taking an empty organic phase containing an extractant, namely octyl decyl tertiary amine in example 4, wherein the mass concentration of germanium in the purifying liquid is 0.0165mol/L, and the ratio of the mass concentration of the extractant, namely trioctyldecyl tertiary amine in the organic phase to the mass concentration of germanium in the liquid is 23:1. example 4 the acidified solution was adjusted with sulfuric acid to 100g/L sulfuric acid solution, mixed with the empty organic phase for 10 minutes according to Vo/va=2:1, and allowed to stand for demixing to give the upper acidified organic phase, which contained 36.8g/L bisulfate ions.

Taking 20.0L of purified solution, dechlorinating by a cuprous salt precipitation method to obtain dechlorinated solution, wherein the solution contains Cl ^- 0.17g/L. Mixing the dechlorinated liquid with the secondary raffinate of the example 4, adding 51.8g of tartaric acid, uniformly mixing to obtain a sulfate solution of a germanium-containing tartaric acid complex, namely a feed liquid, carrying out primary extraction on the sulfate solution and 10.0L of acidified organic phase in a small three-stage countercurrent mixing clarifier, and standing for 10 minutes at 30-35 ℃ for 10 minutes at the temperature of 30-35 ℃ for obtaining primary raffinate which contains Ge compared with Vo/Va=1:2 ⁴⁺ The extraction rates of germanium and tartaric acid are 99.52 percent and 99.84 percent respectively, and the concentration of germanium and tartaric acid in the primary loaded organic phase is 2.42g/L and 14.59g/L respectively.

Mixing the hydrolysis filtrate and washing water in example 4 to obtain 3.0L mixed solution, carrying out secondary extraction on 1.827g/L germanium-containing solution and 39.05g/L tartaric acid and 10.0L primary loaded organic phase in a small secondary countercurrent mixer-settler, wherein the temperature is 30-35 ℃ for 10 minutes and the mixing time is 10 minutes compared with Vo/Va=10:3, and standing for 10 minutes to obtain secondary raffinate which contains Ge ⁴⁺ 0.15g/L, 32.33g/L tartaric acid, and germanium and tartaric acid extraction rates respectivelyThe concentrations of germanium and tartaric acid in the secondary loaded organic were 2.97g/L and 16.61g/L, respectively, at 91.79% and 17.21%.

Mixing 2.0L of secondary loaded organic phase with 0.4L of 80.0g/L sodium hydroxide solution for back extraction, and directly hydrolyzing the organic phase, wherein the temperature is 30-35 ℃ for 10 minutes compared with Vo/Va=5:1, and standing for 10 minutes to obtain a back extraction liquid, wherein the back extraction liquid is a suspension with precipitation, and contains 5.15g/L germanium, 3.0g/L free sodium hydroxide and 73.62g/L tartaric acid. The organic phase is regenerated by mixing and back-extracting the primary back-extracted organic phase with 0.4L of 80.0g/L sodium hydroxide solution, the temperature is 30-35 ℃ and the mixing time is 10 minutes compared with Vo/Va=5:1, and the secondary back-extracted liquid and the empty organic phase are obtained after standing for 10 minutes, wherein the secondary back-extracted liquid is a clear solution, and contains 0.63g/L germanium, 78.5g/L free sodium hydroxide and 9.42g/L tartaric acid. This operation was repeated to obtain 2.0L of a primary stripping suspension and 0.4L of a secondary stripping solution by using 10L of the washing load organic phase, and 160.0g of sodium hydroxide was consumed by the primary stripping solution, 162.3g of tartaric acid was recovered, and the recovery rate was 97.71%.

Taking 2.0L of primary back extraction suspension, adding acidified solution to adjust the pH value to 9.0 under stirring, heating to 75 ℃, adding 31.0g of magnesium sulfate heptahydrate according to 6 times of the germanium amount, reacting for 1.5 hours under heat preservation, and vacuum filtering to obtain 261.5g of hydrolysis filter cake, and obtaining 2.0L of hydrolysis filtrate, 2.43g/L of germanium and 58.46g/L of tartaric acid. Adding fresh water 2.0L into the hydrolyzed filter cake, stirring and washing for 1.0 hour at 75 ℃, and carrying out vacuum suction filtration to obtain 209.3g of water-washed filter cake, thereby obtaining 2.0L of water-washed cake, 0.22g/L of germanium-containing and 8.54g/L of tartaric acid.

The filter cake was washed with water and dried at 280℃to give 94.30g of milky white powder, 25.43 g of germanium, 23.98g of reduced germanium metal.

The statistics of the results of the implementation are shown in Table 1 and Table 2. According to the material liquid germanium metal amount, the germanium metal recovery rate of germanium concentrate reaches 99.92%; the unit consumption of germanium metal tartaric acid in germanium concentrate is 1.35g/g; the unit consumption of germanium metal sodium hydroxide in germanium concentrate is 6.67g.

TABLE 1 germanium metal statistical balance table

Table 2 statistical balance table for tartaric acid

Claims (7)

1. A method for solvent extracting germanium and preparing germanium concentrate, which is characterized by comprising the following steps:

mixing a feed liquid, a secondary raffinate and an acidified organic phase, performing primary extraction to obtain a primary raffinate and a primary loaded organic phase, wherein the feed liquid is a sulfate solution of a germanium-containing tartaric acid complex, the secondary raffinate contains complexing agent tartaric acid, the acidified organic phase contains extractant three Xin Guiwan-group tertiary amine, and the primary raffinate is used for recycling other metals;

mixing the primary loaded organic phase, hydrolyzed liquid and washing water phase produced in the step A, and carrying out secondary extraction to produce secondary raffinate and a secondary loaded organic phase, wherein the hydrolyzed liquid and washing water contain complexing agent tartaric acid, and the secondary raffinate is returned to the step A for use;

mixing the secondary loaded organic phase produced in the step B with sodium hydroxide solution, and carrying out back extraction to produce an empty organic phase and a back extraction liquid;

mixing the unloaded organic phase, sulfuric acid solution and/or acidified liquid produced in the step C, and carrying out acidification and inversion to produce an acidified organic phase and acidified liquid, wherein the acidified organic phase is returned to the step A for use, and part of the acidified liquid is returned to the step for use;

e) Mixing the strip liquor produced in the step C, the partially acidified liquor produced in the step D and magnesium sulfate heptahydrate, hydrolyzing to produce hydrolyzed liquor and hydrolyzed filter cakes, washing the hydrolyzed filter cakes with fresh water to produce washed filter cakes and washing water, returning the hydrolyzed liquor and washing water containing complexing agent tartaric acid to the step B for use, and drying the washed filter cakes to produce germanium concentrate.

2. The method for extracting germanium and preparing germanium concentrate by using solvent according to claim 1, wherein the mass and volume concentration of chloride ions in the feed liquid in the step A is less than 0.2g/L after dechlorination pretreatment.

3. The method for extracting germanium and preparing germanium concentrate by using solvent according to claim 1 or 2, wherein the ratio of the concentration of trioctyldecyl tertiary amine substance as extractant in the acidified organic phase to the concentration of germanium substance in the feed liquid in the step A is 22-24:1.

4. The method for extracting germanium and preparing germanium concentrate by using solvent according to claim 3, wherein the back extraction in the step C is a secondary countercurrent back extraction, the secondary loaded organic phase is mixed with the secondary back extraction liquid to perform primary back extraction, the primary back extraction liquid is produced as the back extraction liquid, the free sodium hydroxide is contained in the primary back extraction liquid by 2.0g/L to 5.0g/L, the primary back extraction organic phase is produced and mixed with sodium hydroxide solution to perform secondary back extraction, and the secondary back extraction organic phase is produced as the empty loaded organic phase.

5. The method for extracting germanium and preparing germanium concentrate by using solvent according to claim 4, wherein the hydrolysis in step E is performed by adding the partially acidified solution produced in step D into the strip solution produced in step C, adjusting PH=9-10, adding magnesium sulfate according to 5-7 times of the weight of germanium in the solution, and mixing and hydrolyzing.

6. The method for extracting germanium and preparing germanium concentrate by using solvent according to claim 5, wherein the drying temperature of the washed filter cake in the step E is 250-300 ℃.

7. The method of solvent extraction of germanium and production of germanium concentrate according to any one of claims 1, wherein the ratio of the secondary extractions in step B is Vo/Va = 10:3 to 4.

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