RU2363749C1 - Method of extracting germanium from solutions - Google Patents

Abstract

FIELD: chemistry. ^ SUBSTANCE: invention relates to hydrometallurgy of rare metals and can be used in treating sulphurous solutions and tar-water from coke and by-product processing, containing germanium. Germanium is extracted from aqueous solutions using cation-exchange chelating extraction agents from the class of hydroxyoximes (LIX 63), alkyloxyquinolines (Kelex 100 or LIX 26), bis(2,4,4-trimethylpentyl)dithiophosphinic acid (CYANEX 301) and others in the presence of rhodonide ions in the initial aqueous solution with concentration of 0.1-1.0 mol/l. Germanium is re-extracted from the extract using caustic soda solutions. ^ EFFECT: increased extraction capacity of the system during extraction of germanium from sulphurous solutions and reduced content of chelating extraction agent in organic phase, as well as carrying out extraction in a wide acidity range. ^ 5 tbl, 7 ex

Description

The invention relates to hydrometallurgy of rare metals and can be used in the processing of germanium-containing sulfate solutions and tar tar waters of coke production.

There is a method of extracting germanium from sulfuric acid solutions and tar resin waters of coke production [Naboychenko S. S., Lebed A. B., Maltsev G. I. et al. A method for extracting and concentrating germanium from solutions. Patent 2293779 Russia, IPC С22В 41/00, С22В 3/20; LLC Mednogorsk Copper-Sulfur Plant, No. 2005101950/02; Declared January 27, 2005; Publ. 02/20/2007, bull. No. 5], which includes the precipitation of germanium in the form of sparingly soluble organic compounds with a mixture of hydroxycarboxylic acid and a long chain amine. As hydroxy acids, tartaric, citric or oxalic acids are used, and as an amine, N-cetylpyridinium chloride or alkyldimethylbenzylammonium chloride in a molar ratio of from 2 to 6 each per mole of germanium.

The disadvantage of this method is the incomplete deposition of germanium, especially in systems with citric acid and N-cetylpyridinium chloride (degree of extraction of germanium in the precipitate, ε = 68.2%), also with tartaric acid and alkyldimethylbenzylammonium chloride (ε = 50.2-64.9 %). The disadvantages of the method include the duration of the process of deposition of germanium and the need to sediment the resulting suspension (12 hours!) Before filtering the pulp.

According to another method [Grever T.N., Loginova E.E., Zaitseva N.G. The study of the selective sorption of germanium and molybdenum from sulfuric acid solutions of complex composition // Bulletin of universities. Non-ferrous metallurgy. (1994), No. 3, p.66-72] the extraction of germanium from sulfate solutions obtained by leaching converter dusts of copper-Nickel production, containing, g / l: 2.4-8 Zn; 3-14.5 Ni; 0.1-0.6 Mo, 20 N ₂ SO ₄ and others, as well as 10 ÷ 60 mg / l Ge, are sorbed using AN-31 anion exchange resin in the Cl form. Germanium is desorbed by sodium hydroxide (NaOH) solutions. The disadvantages of the method are the low sorption rate of germanium (τ = 30-40 hours), as well as the low mechanical stability of the anion exchange resin. The disadvantages of the method include the difficulty of regeneration of the ion exchanger.

The closest in technical essence and the achieved result to the claimed method is a prototype method [G.M. Ritchie, A.V. Ashbrook EXTRACTION. Principles and application in metallurgy. M., Metallurgy, 1983, 408]. Germanium extraction (p.149-150) is carried out using a cation exchange chelating extractant from the class of hydroxy oximes - LIX 63, containing N, O-donor atoms. The active component of LIX 63 is 5.8-diethyl-7-hydroxy-dodecane-6-oxime.

According to this method, from a sulfate solution containing, g / l: 0.2-5 Ge and 120 H ₂ SO ₄ , as well as a small amount of other impurities (4.6 Zn; 0.3 Cu; 2.0 Fe ²⁺ ) germanium is recovered with concentrated LIX 63 (2.27 mol / L active ingredient). (Commodity LIX 63 is a mixture of 70% active extractant and 30% aliphatic diluent-Phillips SX-11, respectively, its molar concentration is 2.27 mol / L [LIX®63, Technical Bulletin, Cognis Corporation (USA)]. Extraction is carried out at O: B = 1: 1, the concentration of sulfuric acid should be above 90 g / L. Reextraction of germanium from the organic phase is carried out with sodium hydroxide solutions (150 g / l NaOH).

A significant disadvantage of this method is the low extraction ability of LIX 63, as a result of which it is necessary to use an extractant with a high concentration of 2.27 mol / L in the process. In addition, effective extraction of Ge takes place only for strongly acidic solutions (H ₂ SO ₄ > 90 g / l), which is also a disadvantage, since this leads to an increased consumption of acid, and subsequently an alkaline reagent to neutralize it.

The technical result of the invention is to increase the extraction of germanium from sulfuric acid solutions (degree of extraction of germanium, ε). As a result, it is possible to reduce the content of cation exchange chelating extractant (HR) in the organic phase, as well as conducting extraction in a less acidic region than in the known prototype method.

This goal is achieved in that, in contrast to the known method for the extraction of germanium from sulfuric acid solutions, including extraction of germanium with a cation exchange chelating extractant in a diluent and reextraction of germanium with sodium hydroxide solutions, the extraction process is carried out in the presence of the thiocyanate ion in the aqueous phase at a molar concentration of 0, 1-1.0 mol / L.

As cation exchange chelating extractants (HR), reagents containing N, O- can be used; S, S and O, O donor atoms. When using extractants containing N, O-donor atoms, it is preferable to use extractants from the class of hydroxy oximes, in particular LIX 63, or derivatives of alkyloxyquinoline, for example 7-alkenyl-8-hydroxyquinoline (trademark Kelex 100 or LIX 26) [Kelex®100, Technical Bulletin 1241, Ashland Chemicals (USA)]. When using extractants containing 8.8-donor atoms, it is possible to use bis (2,4,4, -trimethylpentyl) dithiophosphinic acid, trademark CYANEX 301 [CYANEX®301, Technical Bulletin, Cytec, (Canada)]. Beta-diketones, for example 1-phenyl-1,3-decanedione, trademark LIX 54 [LIX54®-100., Can be used as extragens with O, O donor atoms. Technical Bulletin, Cognis Corporation (USA)] or other oxygen-containing reagents.

The increase in germanium extraction from solutions by cationic chelating extractants in the presence of a thiocyanate ion is apparently due to the formation of a triple complex in the organic phase (Ge-HR-SCN), i.e. when the thiocyanate ion is included in the extracted germanium compound.

As the supplier of the thiocyanate ion, any salts with singly charged cations (for example, NaSCN, NH ₄ SCN or KSCN) can be used.

The process is proposed to be carried out at a concentration of thiocyanate ion in the aqueous phase of 0.1-1.0 mol / l and with acidity of solutions ≤100 g / l in sulfuric acid. At other concentrations of the thiocyanate ion, the extraction of germanium worsens or its extraction improves slightly.

As solvents, ordinary solvents from a number of aliphatic hydrocarbons (kerosene, petroleum paraffins, etc.) are used; modifiers (2-ethylhexanol, octanol-1) can be used.

The following are examples of the proposed method.

Example 1

Table 1 shows the data on the extraction of germanium from sulfuric solutions with solutions of LIX 63 (5,8-diethyl-7-hydroxy-dodecane-6-oxime) in kerosene in the absence and presence of a thiocyanate ion in the aqueous phase. The compositions of the extractants, the initial aqueous solutions, as well as the experimental conditions are given in table 1. For comparison, the table shows the data on the extraction of germanium with a solution of LIX 63 in an aliphatic diluent - Phillips SX-11 (experiment 11, prototype method).

Table 1 Germanium extraction with solutions of LIX 63 in kerosene in the absence and presence of a thiocyanate ion in the aqueous phase The original aqueous solution; g / l: 0.2 Ge; 25 H ₂ SO ₄ ; (No. 1) 0.2 Ge; 25 H ₂ SO ₄ ; NH ₄ SCN (No. 2-10); 0.2 Ge; 100 H ₂ SO ₄ ; (No. 11) Extraction conditions: Т = 22 ° С, τ = 2 h, O: В = 1: 1 Experience number concentration ε,% LIX 63 NH ₄ SCN, mol / L Germany, mg / l mol / l % (wt.) water phase org phase one 2.27 70 - 67.0 133 66.7 2 2.27 70 0.1 11.6 188.4 94.2 3 2.27 70 0.25 6.2 193.8 96.9 four 2.27 70 1,0 2,8 197,2 98.6 5 2.27 70 2.0 2,4 197.6 98.8 6 0.056 1.75 1,0 22.5 177.5 88.8 7 0.113 3,5 1,0 16,0 184.0 92.0 8 0.227 7.0 1,0 5.8 194.2 97.1 9 0.56 17.5 1,0 2,8 197,2 98.6 10 1.12 35 1,0 2,3 197.7 98.9 11 (proto
type of) 2.27 70 - 28.6 171.4 85.7

The table shows that at a constant concentration of the extractant with an increase in the content of rhodanide in the initial aqueous solution, a significant increase in the extraction of germanium is observed (No. 2-5), especially in comparison with systems where there is no Rodanide ion (No. 1 and 11). An increase in the degree of extraction is also observed with a constant concentration of rhodanide ion and an increase in the concentration of extractant (No. 6-10). In all cases, the extraction of Ge by the proposed method (No. 2-10) is higher than by the known (No. 11).

It is seen that the range of optimal concentrations of rhodanide in the initial aqueous solution is in the range of 0.1-1.0 mol / L. When the concentration of rhodanide ion is less than 0.1 M, the extraction of germanium worsens, at more than 1.0 M its extraction improves slightly (No. 2-5). It is seen that, depending on the conditions, the concentration of the extractant can be significantly reduced with a sufficiently high extraction of germanium (No. 6-10). The acidity of the aqueous phase during the extraction of germanium by the proposed method (25 g / l H ₂ SO ₄ ; No. 2-10) is less than by the known

(100 g / l H ₂ SO ₄ ; No. 11).

Example 2

Analogously to example 1, germanium was extracted from sulfuric solutions with Kelex 100 extractant (7-alkenyl-8-hydroxyquinoline) in a diluent in the absence and presence of a thiocyanate ion in the aqueous phase. The compositions of extractants, initial aqueous solutions, experimental conditions, as well as the data obtained are given in table.2. For comparison, the table shows the data on the extraction of germanium with a solution of LIX 63 in an aliphatic diluent - Phillips SX-11 (No. 10, prototype method).

The table also shows that in all cases, the extraction of Germany by the proposed method is significantly higher (No. 2-9) than by the known (No. 10, prototype). Moreover, the concentration of the chelating reagent (Kelex 100) in the solvent according to the proposed method is much lower than in the known. The acidity of the aqueous phase during the extraction of Germany by the proposed method (25 g / l H ₂ SO ₄ ; No. 2-9) is also less than by the known (100 g / l H ₂ SO ₄ ; No. 10).

table 2 Germanium extraction with Kelex 100 solutions in a diluent in the absence and presence of a thiocyanate ion in the aqueous phase Organic phase: Kelex 100 in kerosene + 10% octanol-1 The original aqueous solution; g / l: 0.225 Ge; 25 H ₂ SO ₄ ; (No. 1); 0.225 Ge; 25 H ₂ SO ₄ ; NH ₄ SCN (No. 2-5); 0.2 Ge; 25 H ₂ SO ₄ ; NH ₄ SCN (No. 6-9) 0.2 Ge; 100 H ₂ SO ₄ ; (No. 10) Extraction conditions: Т = 22 ° С, τ = 2 h, O: В = 1: 1 Experience number concentration ε,% LIX 63 NH ₄ SCN, mol / L Germany, mg / l mol / l % (mass.) water phase org phase one 0.05 1.72 - 91 134 59.5 2 0.05 1.72 0.05 13.0 212 94.2 3 0.05 1.72 0.10 9,4 215.6 95.8 four 0.05 1.72 0.25 1,6 223.4 99.3 5 0.05 1.72 0.50 0.1 224.9 99.9 6 0.02 0.69 0.25 8.0 192 96.0 7 0,03 1,03 0.25 3.4 196.6 98.3 8 0.04 1.38 0.25 1,5 198.5 99.3 9 0.05 1.72 0.25 1.4 198.6 99.3 10 (proto-
type of) 2.27 (LIX 63) 70 - 28.6 171.4 85.7

Example 3

Table 3 shows the data on the extraction of germanium from sulfuric solutions with solutions of Cyanex 301 (bis (2,4,4, -trimethylpentyl) dithiophosphinic acid) in kerosene in the absence (No. 1, 5, 8) and presence (No. 2-4, 6, 7) of the thiocyanate ion in the aqueous phase. The compositions of the extractants, the initial aqueous solutions, as well as the experimental conditions are given in table.3. For comparison, the table shows the data on the extraction of germanium with a solution of LIX 63 in an aliphatic diluent - Phillips SX-11 (No. 8, prototype method).

It can be seen that in all cases, the introduction of thiocyanate significantly improves germanium extraction and Ge extraction by the proposed method (No. 2-4, 6, 7) higher than by the known (No. 11). It is also seen that an increase in the concentration of rhodanide ion is higher than 1.0 mol / L, is unjustified.

Table 3 Germanium extraction with solutions of Cyanex 301 in kerosene in the absence and presence of a thiocyanate ion in the aqueous phase The original aqueous solution; g / l: 0.2 Ge; 100 H ₂ SO ₄ ; NH ₄ SCN (No. 2-7); 0.2 Ge; 100 H ₂ SO ₄ ; (No. 1, 8) Extraction conditions: Т = 22 ° С, τ = 2 h, O: В = 1: 1 Experience number concentration ε,% LIX 63 NH ₄ SCN, mol / L Germany, mg / l mol / l % (wt.) water phase org phase one 0.1 4.6 - 158 42 21.0 2 0.1 4.6 0.5 26 174 87.0 3 0.1 4.6 1,0 9 191 95.5 four 0.1 4.6 2.0 7 193 96.5 5 0.5 23 - 75 125 62.5 6 0.5 23 0.25 traces (<0.1) 200 ≈100 7 0.5 23 0.5 traces (<0.1) 200 ≈100 8 (proto-
type of) 2.27 (LIX 63) 70 - 28 172 85.7

Example 4

This example illustrates the possibility of using oxygen-containing chelating organic acids for the extraction of germanium in the presence of a thiocyanate ion. The results are shown in Table 4, where LIX 54 is beta-diketone (1-phenyl-1,3-decanedione), and P2EHFNA is poly (2-ethylhexyl) phosphonitrile acid (TU 95.104.86).

Table 4 Extraction of germanium by oxygen-containing chelating extractants in kerosene in the absence and presence of a thiocyanate ion in the aqueous phase Extractant: LIX-54 (No. 1, 2); P2EGFNA (No. 3, 4) The original aqueous solution; g / l: 0.185 Ge; 100 H ₂ SO ₄ ; (No. 1, 3); 0.185 Ge; 100 H ₂ SO ₄ ; 1,0 M NH ₄ SCN (No. 2,4) Extraction conditions: Т = 22 ° С, τ = 2 h, O: В = 1: 1 Experiment number
that extractant concentration LIX 63 NH ₄ SCN, Germany, mg / l ε,% mol / l % (wt.) mol / l water phase org phase one LIX-54 1,0 32 - 170 fifteen 8.0 2 LIX-54 1,0 32 1,0 48 137 74.0 3 P2EGFNA 0.5 21 - 157 28 15.0 four P2EGFNA 0.5 21 1,0 37 148 80.0

As can be seen from the table, in the presence of a thiocyanate ion, it is possible to efficiently extract germanium using oxygen-containing chelating organic acids, which is practically impossible in the absence of thiocyanate.

Example 5

Sulfate solution containing, g / l: 0.18 Ge; 3.5 Zn; 0.2 Cu, 28 H ₂ SO ₄ and 0.25 M ammonium thiocyanate, were contacted for 1 hour at O: B = 1: 1 and a temperature of 22 ° C with an organic phase containing 0.05 M Kelex 100 + 10% octanol-1 in kerosene. The phases were separated; germanium in the aqueous phase (raffinate) was analyzed. Found in the raffinate of 0.007 g / l of germanium, respectively, its extraction into the organic phase was 96.1%. According to the prototype, the germanium recovery is 85.7%.

Example 6

The solution simulating germanium suprasmal water with pH = 2.5 was acidified with concentrated sulfuric acid to a final acidity of 26 g / l, after which ammonium thiocyanate was introduced into the solution to a concentration of 0.25 mol / l. The germanium content in the acidified solution was 53 mg / L. This solution was contacted for 1 hour at O: B = 1: 1 and a temperature of 22 ° C with an organic phase containing 0.56 M LIX 63 + 10% octanol-1 in kerosene. The phases were separated; germanium in the aqueous phase (raffinate) was analyzed. 2.6 mg / L of germanium was found in the raffinate; accordingly, its extraction into the organic phase was 95.1%. According to the prototype, the germanium recovery is 85.7%.

Example 7

From a sulfuric acid solution containing 0.2 g / l of germanium, 50 g / l of sulfuric acid and 0.5 mol / l of ammonium thiocyanate, germanium was extracted for 1 hour at O: B = 1: 1 and a temperature of 22 ° C with the organic phase containing 0.56 M LIX 63 + 10% octanol-1 in kerosene. The phases were separated; germanium in the aqueous phase (raffinate) was analyzed. Found in raffinate 0.006 g / l of germanium, respectively, its concentration in the organic phase is 0.194 g / l. Recovery to the organic phase is 97.0%.

Under the same conditions, germanium was extracted with an organic phase containing 0.05 M Kelex 100 + 10% octanol-1 in kerosene. After extraction, germanium was found in the raffinate 0.0005 g / l, respectively, its concentration in the organic phase is 0.1995 g / l. Recovery to the organic phase is 99.75%.

Germanium was similarly extracted with an organic phase containing 0.5 M Cyanex 301 + 10% octanol-1 in kerosene. After extraction, germanium was found in the raffinate of 0.001 g / l, respectively, its concentration in the organic phase is 0.199 g / l. Recovery to the organic phase is 99.5%.

The obtained extracts were treated with an alkali solution with a concentration of 150 g / l NaOH at O: B = 5: 1 to reextract germanium from the organic phase.

The data are presented in table.5.

Table 5 Reextraction of Germany from extracts Organic phase: I - 0.56 M LIX 63; II - 0.05 M Kelex 100; III - 0.5 M Cyanex 301; diluent - kerosene + octanol-1 Stripping agent: solution of 150 g / l NaOH Reextraction conditions: Т = 22 ° С, τ = 1 h, O: В = 5: 1 Organic
kay phase germanium content, mg / l ε,% initial org phase org phase after reextraction reextract I 194.0 4.0 950.0 98.0 II 199.5 7.5 960.0 96.5 III 199.0 6.0 965.0 97.1

As can be seen, in all cases, regardless of the composition of the organic phase (extract), back-extraction is quite effective.

The claimed invention is industrially applicable, because it can be used in the production of both for the processing of germanium-containing solutions of metallurgical industries, and for tar water coke production. The proposed extractants are commercially available and commercially available.

The implementation of the proposed method in comparison with known solutions has the following advantages:

- simplicity and efficiency of germanium extraction;

- expanding the range of acidity of processed solutions;

- expanding the range of extractants used;

- the use of extractants with a low concentration in the diluent.

Claims (1)

A method for extracting germanium from aqueous solutions, including extraction of germanium with a cation exchange chelating extractant in a diluent and reextraction of germanium with sodium hydroxide solutions, characterized in that the extraction is carried out in the presence of a thiocyanate ion in the aqueous phase at a concentration of 0.1-1.0 mol / l.