RU2378402C2 - Extraction method of germanium from sulfuric solutions - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method of germanium extraction from sulfuric solutions includes germanium extraction by organic phase with chelating extractant, containing N,O- donor atoms, in diluter and germanium re-extraction by solution of caustic soda. Additionally extraction is implemented by organic phase in the form of mixture of chelating extractant, containing N,O-donor atoms, with bis-(2,4,4,-trimethyl amyl) dithiophosphonic acids (CYANEX 301) in diluter at molar ratio of chelating extractant and CYANEX 301 in organic phase =0.25÷4.5:1.

EFFECT: increasing of extraction ability of system at extraction of germanium from sulfuric solutions, reduction of chelating extractant content in organic phase, implementation of extraction in area of low acidity.

3 tbl, 5 ex

Description

The invention relates to hydrometallurgy of metals and can be used in the processing of sulfate solutions containing germanium.

The need to create the present invention is caused by the complexity of existing methods for extracting germanium from these solutions.

The known method [Olsen T., Foster L. et al. Solvent extraction of Ga and Ge from ores deposit Apex. // Proceedings of Symp. "Precious and Rare Metal", Albuquer N.M., April 6-8, 1988, Amsterdam etc., 1989, p.531-545], in which germanium from the sulfate solution, after removal of copper by cementation, is precipitated with sulfide in the form of sulfide.

The disadvantages of the method are: the need to use a toxic reagent (hydrogen sulfide); high consumption of sulfuric acid in the process, since the precipitation of GeS ₂ takes place only at high acidity (> 50 g / l H ₂ SO ₄ ); precipitation is difficult to filter. It should be noted that, from a technological point of view, further processing of sulfide sludge is rather cumbersome.

According to another method [Grever T.N., Loginova E.E., Zaitseva N.G. The study of selective sorption of germanium and molybdenum from sulfuric acid solutions of complex composition // Bulletin of universities. Non-ferrous metallurgy (1994), No. 3, pp.66-72] extraction of germanium from sulfate solutions obtained by leaching dust from smelters of a copper-nickel plant (6–15 mg / l Ge, 10-15 g / l H ₂ SO ₄ ), is carried out by sorption using anion exchange resin AN-31. Anion exchange resin contains secondary and tertiary amino groups, as well as hydroxyl groups. Germanium is desorbed by sodium hydroxide (NaOH) solutions. The disadvantage of this method is the low chemical (oxidation of hydroxy groups) and mechanical stability of the anion exchange resin, which does not allow its repeated use in sorption-desorption cycles. The disadvantages of the method include the high cost of the sorbent.

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., Publishing House "Metallurgy", 1983, 408 p.]. According to this method, the extraction of germanium (p.149-150) is carried out using a chelating extractant, from the class of α-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: 0.2-5.0 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 a concentrated solution of LIX 63 (2.27 mol / L of 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 solutions of sodium hydroxide (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 in the process. As a rule, an extractant without dilution is used, with a concentration of 2.27 mol / L. In addition, effective extraction 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 then an alkaline reagent to neutralize it.

The technical result of the invention is to increase the extraction ability of the system when extracting germanium from sulfuric acid solutions (increase in the distribution coefficients of germanium, D _Ge ). As a result, it is possible to reduce the content of chelating extractant (HR) in the organic phase, as well as conducting extraction in a much 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 the extraction of germanium with a chelating extractant containing N, O-donor atoms in a diluent and reextraction of germanium with sodium hydroxide solutions, the process is carried out in the presence of bis (2.4 , 4, -trimethylpentyl) -dithiophosphinic acid at a molar ratio of chelating extractant to bis (2,4,4-trimethylpentyl) dithiophosphinic acid = 0.25 ÷ 4.5: 1.

As chelating extractants containing N, O-donor atoms (HR), extractants from the class of α-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)].

Bis (2,4,4-trimethylpentyl) dithiophosphinic acid (HA) under the brand name CYANEX 301 is manufactured by Cytec [CYANEX®301, Technical Bulletin, Cytec (Canada)].

The improvement in the extraction of germanium by mixtures of extractants, in comparison with individual extractants, exceeding their additive contribution, is caused by the manifestation of a synergistic effect (S). The synergism is apparently caused by the formation of a triple complex in the organic phase (Ge-HR-CYANEX 301).

It is proposed to use mixtures with a molar ratio of chelating extractant (HR): CYANEX 301 (HA) = 0.25 ÷ 4.5: 1 and with acidity of solutions below 90 g / l in sulfuric acid.

At different HR: HA ratios, germanium extraction is impaired, or its recovery is not significantly improved.

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 individual extractants LIX 63 (5,8-diethyl-7-hydroxy-dodecane-6-oxime), CYANEX 301 (bis (2,4,4-trimethylpentyl) dithio-phosphinic acid) as well as their mixtures in a diluent. 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 (No. 6, prototype method). The table shows that, with an increase in the content of CYANEX 301 in the mixture of extractants, there is a significant increase in the distribution coefficients of germanium (D _{HR + HA} ), (No. 2-5), i.e. in this system, a synergistic effect (S) takes place, which is especially noticeable at the molar ratio HR: HA = 3 ÷ 4.5: 1 (No. 4, 5). With a lower content of HA, its value is relatively low (No. 2, 3), with a larger content, it increases slightly.

The table also shows that under optimal conditions, the extraction of Germany by the proposed method is significantly higher (No. 4, 5) than by the known (No. 6, prototype). In this case, the concentration of the chelating reagent (LIX 63) in the solvent according to the proposed method is much lower than in the known, 0.88 M and 2.27 M, respectively. In addition, the acidity of the aqueous phase in the extraction of germanium by the proposed method (25 g / l H ₂ SO ₄ ; No. 2-5) is also much less than by the known (100 g / l H ₂ SO ₄ ; No. 6).

Example 2

Analogously to example 1, germanium was extracted from sulfuric solutions with individual extractants Kelex 100 (7-alkenyl-8-hydroxyquinoline), CYANEX 301, as well as their mixtures in a diluent. The compositions of extractants, initial aqueous solutions, experimental conditions, as well as the obtained data 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. 6, prototype method).

The table shows that, with an increase in the content of CYANEX 301 in the extractant mixture, as in the previous case, there is a significant increase in the distribution coefficients of germanium (D _{HR + HA} ), (No. 2-5). The synergistic effect (S) is especially noticeable with the molar ratio HR: HA = 0.25 ÷ 1: 1 (No. 3-5). With a lower content of HA, its value is relatively low (No. 2), with a higher content, the extraction of germanium practically does not increase (No. 5).

Table 1 Germanium extraction from sulfate solutions by individual extractants (LIX 63, CYANEX 301), as well as their mixtures in kerosene + 10% octanol-1 Extractants: HR - LIX 63; ON - CYANEX 301; HR + ON - a mixture of LIX 63 and CYANEX 301 Initial aqueous solution, g / l: 0.2 Ge; 25.0 H ₂ SO ₄ ; (No. 1-5); 0.2 Ge; 100.0 H ₂ SO ₄ ; (No. 6) Extraction conditions: Т = 22 ° С, τ = 2 h, O: В = 1: 1 No. The composition of the mixture, M * D _{HR + HA} ε _{HR + HA} ,% Composition HR, M D _HR ε _HR ,% Composition ON, M D _ha ε _HA ,% ** S one - - - 0.88 1,07 51.7 - - - - 2 0.88M HR + 0.05M ON 1.94 66.0 - - - 0.05 0.24 19.3 1.48 3 0.88M HR + 0.1M AT 3.25 76.5 - - - 0.1 0.27 21,2 2.42 four 0.88M HR + 0.2M ON 15.66 94.0 - - - 0.2 0.29 22.5 11.5 5 0.88M HR + 0.3M ON 17.0 94.5 - - - 0.3 0.34 25,4 12.05 6 - - - 2.27 HR (prototype) 6.0 85.7 - - - - * D = С _Ge (org.) / С _Ge (в.) - distribution coefficient of germanium; ** S - synergistic effect = D _{HR + HA} / D _HR + D _HA , where D _HR and D _HA are the distribution coefficients of germanium by individual extractants (LIX63 and CYANEX 301), respectively, and D _{HR + HA} - in a mixture of extractants

The table also shows that in all cases, the extraction of Germany by the proposed method is significantly higher (No. 2-5) than by the known (No. 6, prototype). The concentration of the chelating reagent (Kelex 100) in the solvent according to the proposed method is much lower than in the known, 0.05 M and 2.27 M, respectively. The acidity of the aqueous phase during the extraction of germanium by the proposed method (25 g / l H ₂ SO ₄ ; No. 2-5) is also significantly less than by the known (100 g / l H ₂ SO ₄ ; No. 6).

Example 3

Table 3 shows the data on the extraction of germanium from sulfate solutions with individual extractants LIX 63, CYANEX 301, as well as their mixtures in a diluent at a constant concentration of CYANEX 301 and a variable concentration of LIX 63. The compositions of the extractants, initial aqueous solutions, and experimental conditions are given in table. 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. 5, prototype method).

From table 3 it is seen that in all cases, the technological parameters of the proposed method (No. 2-4) are better than the known (No. 5) - higher germanium extraction and lower concentration of LIX 63 and sulfuric acid.

Example 4

Sulfate solution containing, g / l: 0.18 Ge; 3.5 Zn; 0.2 Cu and 28.0 H ₂ SO ₄ were contacted for 1 hour at O: B = 1: 1 and a temperature of 22 ° C with an organic phase containing 0.88 M LIX 63 + 0.3 M CYANEX 301+ 10% octanol-1 in kerosene. The phases were separated; germanium in the aqueous phase (raffinate) was analyzed. 0.012 g / l of germanium was found in the raffinate, respectively, its extraction into the organic phase was 93.3%. According to the prototype, the germanium recovery is equal to 85.7%.

table 2 Germanium extraction from sulfate solutions by individual extractants (KELEX 100, CYANEX 301), as well as their mixtures in kerosene + 10% octanol-1 Extractants: HR - KELEX 100; ON - CYANEX 301; HR + ON - a mixture of KELEX 100 and CYANEX 301 Initial aqueous solution, g / l: 0.2 Ge; 25.0 H ₂ SO ₄ ; (No. 1-5); 0.2 Ge; 100.0 H ₂ SO ₄ ; (No. 6) Extraction conditions: Т = 22 ° С, τ = 2 h, O: В = 1: 1 No. The composition of the mixture, M D _{HR + HA} ε _{HR + HA} ,% Composition HR, M D _HR ε _HR ,% Composition ON, M D _ha ε _HA ,% S one - - - 0.05 1.47 59.5 - - - - 2 0.05M HR + 0.025M ON 13.3 93.0 - - - 0,025 0.21 17.4 7.9 3 0.05M HR + 0.05M ON 32,3 97.0 - - - 0.05 0.24 19.3 18.9 four 0.05M HR + 0.1M AT 51.6 98.1 - - - 0.1 0.27 21,2 29.3 5 0.05M HR + 0.2M ON 124 99,2 - - - 0.2 0.29 22.5 70.45 6 - - - 2.27 HR (prototype) 6.0 85.7 - - - -

Table 3 Germanium extraction from sulfate solutions by individual extractants (LIX 63, CYANEX 301), as well as their mixtures in kerosene + 10% octanol-1 Extractants: HR - LIX 63; ON - CYANEX 301; HR + ON - a mixture of LIX 63 and CYANEX 301 Initial aqueous solution, g / l: 0.1 Ge; 25.0 H ₂ SO ₄ ; (No. 1-4); 0.2 Ge; 100.0 H ₂ SO ₄ (No. 5) Extraction conditions: Т = 22 ° С, τ = 1 h, O: В - 1: 1. (No. 5; τ = 2 h) No. The composition of the mixture, M D _{HR + HA} ε _{HR + HA} ,% Composition HR, M D _HR ε _HR ,% Composition ON, M D _ha ε _HA ,% S one - - - - - - 0.2 0.29 22.5 - 2 0.57M HR + 0.2M AT 7.2 87.8 0.57 HR 0.78 43.8 - - - 6.8 3 0.88M HR + 0.2M ON 14.3 93.5 0.88 HR 0.99 49.8 - - - 11,2 four 1.14M HR + 0.2M AT 16.6 94.3 1.14 HR 1.14 53.3 - - - 11.6 5 - - - 2.27 HR (prototype) 6.0 85.7 - - - -

Example 5

From a sulfuric acid solution containing 1.58 g / l of germanium and 50 g / l of sulfuric acid, germanium was extracted for 1 hour at O: B = 1: 1 and a temperature of 22 ° C with an organic phase containing 0.88 M LIX 63 +0.2 M CYANEX 301 + 10% octanol-1 in kerosene. The phases were separated; germanium in the aqueous phase (raffinate) was analyzed. 0.09 g / l of germanium was found in the raffinate; accordingly, its concentration in the organic phase is 1.49 g / l. Extraction into the organic phase is 94.3%.

The obtained extract, for reextraction of germanium from the organic phase, was treated with an alkali solution with a concentration of 200 g / l NaOH at O: B = 5: 1 for 1 hour and a temperature of 22 ° C.

The phases were separated; germanium was analyzed in a reextract. Found in a re-extract of 6.85 g / l Germany. The extraction of germanium into the reextract in one step was 91.9%.

Claims (3)

1. A method of extracting germanium from sulfuric acid solutions, comprising extracting germanium with an organic phase with a chelating extractant containing N, O-donor atoms in a diluent and re-extracting germanium with a sodium hydroxide solution, characterized in that the extraction is carried out with an organic phase in the form of a mixture of a chelating extractant containing N, O-donor atoms, with bis (2,4,4-trimethylpentyl) dithiophosphinic acid (CYANEX 301) in a diluent at a molar ratio of chelating extractant and CYANEX 301 in the organic phase = 0.25 ÷ 4.5: 1. 2. The method according to claim 1, characterized in that as a chelating extractant containing N, O-donor atoms, α-hydroxy oxime - LIX 63 is used and extraction is carried out at a molar ratio of LIX63 and CYANEX 301 in the organic phase = 3.0 ÷ 4.5: 1. 3. The method according to claim 1, characterized in that as a chelating extractant containing N, O-donor atoms, alkyloxyquinolines - Kelex 100 or LIX 26 are used and extraction is carried out at a molar ratio of Kelex 100 or LIX 26 and CYANEX 301 in the organic phase 0.25 ÷ 1: 1.