RU2116363C1 - Metal desorption process - Google Patents

Abstract

FIELD: electroplating industry. SUBSTANCE: in order to bring back 56-99% of metal sorbed from wash bath into electrolyzer, metal-saturated sorbent is treated by eluting solution containing sodium and/or ammonium salts to produce eluate concentrate with makeup, after some lacking component are added, corresponding to commercial electrolyte composition. EFFECT: simplified metal desorption process. 3 cl

Description

 The invention relates to hydrometallurgy of non-ferrous metals, and in particular to a method for desorption of metal from a saturated sorbent, and can be used in electroplating to design a closed waste-free (for metal) production, while solving environmental problems.

 Known methods for the desorption of metals, in particular nickel, copper, zinc from a saturated sorbent by treatment with solutions of acids / 1-5 /, salts / 3, 6, 7 /, mixed solutions of acids and salts / 8, 9 /, salts and alkalis / 10 , 11 /, as well as sequential treatment with solutions of salt and acid / 12 /. However, none of the known methods allows the use of eluates without additional processing in electroplating to form a closed waste-free (metal) production, i.e. returning the eluate as a metal component of the salt component of the electrolyte immediately after elution into the electrochemical bath. As a rule, metal regeneration from the eluate consists in obtaining regeneration products in the form of pure metal salts, suitable for reuse in production with the aim of re-preparing and adjusting the working electrolytes / 13 /, which is accompanied by additional technological stages (cementation, deposition, electrolysis, ion-exchange processing ), each of which is carried out in several stages. For example, copper is usually regenerated by crystallization / 13 /, based on the limited solubility of its salts in an aqueous solution of sulfuric acid: as the concentration of the latter increases, the solubility of copper sulfate decreases - salt crystals precipitate upon cooling. To extract zinc, use the combined cation exchange-anion exchange method / 14 /: the filtrate eluate obtained by desorption of zinc from saturated KU-2 cation exchange resin by filtration with a solution of sodium chloride is sent to anion exchange resin AB-17 in the CI form, where zinc is absorbed as an anionic complex; after regeneration of the anion exchange resin with water, zinc (in the form of chloride) is returned to production. The desorption of nickel from saturated KU-2 cation exchanger is recommended / 15 / to be carried out with 10% solutions of sulfuric acid or sodium sulfate; in this case, the first portions of the sulfate eluate concentrate should be sent to electrodialysis processing, nickel-poor eluates should be sent to the reprocessing of saturated cation exchange resin.

Closest to the proposed method is / 5 /, in which copper was eluted with AB-16G and ANKB-7 ion exchangers saturated with it, with 27-30% sulfuric acid. During desorption, 60–70% of the sorbed copper was removed by the first 0.5–0.7 volumes of the eluate concentrate of the composition, g / l: 40–50 Cu, 50–65 H ₂ SO ₄ ; the remaining 2–3 volumes of copper-poor eluate were used as working back. Electrolyte copper powder was extracted from the concentrate eluate using traditional autoclave reduction technology; sulfuric acid in the process of copper recovery was regenerated and returned to circulation. The method allows to extract copper in the form of metal, which greatly complicates the process of its return to galvanic production, since electrolytes are mainly aqueous salt systems with a complex composition.

 The objective of the present invention is to develop a method of desorption of metals from saturated sorbents to produce a marketable electrolyte of a given composition in one technological stage, which greatly simplifies the creation and design of a closed waste-free (for metal) electrochemical coating method by returning the sorbed-desorbed metal without additional processing of eluates -concentrates in the main production - galvanic bath.

 The technical result of the invention is to simplify the return of 56 - 99% of the sorbed metal after desorption (the first 1-2 volumes of metal-rich eluate) in the form of a commodity electrolyte in a galvanic bath; Registration of a closed waste-free (for metal) galvanic production using poor (for metal) eluates as an eluent solution.

 The technical result is achieved in that the desorption of the metal from the saturated sorbent is carried out with an eluent solution of a composition identical to the composition of the salt component of a commodity electrolyte containing sodium and (or) ammonium salts, reinforced with the equivalent metal content in a commodity electrolyte by the amount of sodium and (or) ammonium salts with anion, the same name anion of a metal-containing component of a commercial electrolyte using poor (for metal) eluates as an eluent of a saturated sorbent.

 Distinctive features of the invention are: use as a eluent of a solution identical in composition and concentration to the salt component of a commodity electrolyte, fortified with an equivalent metal content in a commodity electrolyte by the amount of sodium and (or) ammonium salts with an anion of the same name as the metal-containing component of a commodity electrolyte using poor (by metal) eluates as an eluting solution. These distinguishing features are significant because make it possible to simplify the process of returning sorbed-desorbed metal to a plating bath and designing a closed waste-free (for metal) plating technology. The proposed method for preparing the composition of the eluting solution is the most optimal, because only the use of such a solution for desorption of metal from a saturated sorbent allows one to obtain 1-2 volumes of the eluate-concentrate composition identical to the composition of the commercial electrolyte, and return them without further processing to the main production. The simplification of the process also occurs due to the repeated use of poor eluates as an eluting solution, which ensures almost waste-free (for metal) production.

 It was experimentally established that commodity electrolytes of a given composition, containing less than 50 g-ion / l of the base metal and a salt component of sodium and (or) ammonium salts, can be regenerated by treating saturated sorbents with specially prepared eluting solutions. When determining the composition of such an eluting solution, one should proceed from the given composition of a commercial electrolyte taking into account that sodium and (or) ammonium cations in the process of passing the eluent solution through a layer of metal-saturated cation exchanger are exchanged for sorbed metal cations in an equivalent ratio, and the concentration introduced with sodium salts and (or) ammonium anions remains virtually unchanged. The composition of such an eluting solution consists of the composition of the salt component of a commodity electrolyte with the addition of an additional quantity per unit volume of sodium and (or) ammonium salts in a ratio equivalent to the content of the base metal in the commodity electrolyte. To prevent an increase in the component nature of a complex system, which is a commodity electrolyte, sodium and (or) ammonium salts are taken with the same anion relative to the metal component of the commodity electrolyte. It was also found that commodity electrolytes containing more than 50 g-ion / l of metal can not be obtained in any amount significant for production by the proposed method, which is apparently limited by the theoretical capacity of the sorbents.

The method is as follows. Based on the composition of the commercial electrolyte and the concentrations of its components, determine the composition and concentration of the components of the eluting solution, prepare it by dissolving the calculated amount of salts in water in a fixed volume; fractional elution; determine the content of metal ions in successive parts of the eluate; determine (according to the analysis) the volume of the eluate concentrate, the concentration of which for metal is identical to the concentration of metal in a commodity electrolyte; this volume of the eluate concentrate after adding the missing components is sent as a commodity electrolyte in a galvanic bath; the remaining metal-poor eluate is used as an eluent repeatedly to produce a marketable electrolyte, thereby achieving practical waste-free (metal) of the proposed method. So, to obtain from the Ni-containing cation exchanger KU-2 commercial Nickel electrolyte of a given composition / 16 /, g / l:
Nickel sulfate NiSO ₄ • 7H ₂ O - 75 (15.7 g-ion / l Ni ²⁺ )
Sodium sulfate Na ₂ SO ₄
10H ₂ O - 50 (22.0 g / l Na ₂ SO ₄ )
Boric acid - 25
Sodium Chloride - 10
containing 15.7 g-ion / l of nickel, an eluting solution is prepared, in one liter of which, in addition to 50 g of Na ₂ SO ₄ • 10H ₂ O (22.0 g of Na ₂ SO ₄ ) and 10 g of NaCl, Na ₂ SO _{4 is} additionally contained in an amount equivalent to the concentration of nickel sulfate in a commodity electrolyte of a given composition, i.e. 37.9 g of Na ₂ SO ₄ . The results of the elution of Nickel from the resin with an eluting solution containing, according to the calculation, 10 g / l sodium chloride and 59.9 g / l Na ₂ SO ₄ (22 + 37.9) are presented in the table. In this case, the KU-2 Ni-resin layer in a 120 ml column containing 5.0530 g nickel ion was washed n times with an eluting solution after draining water (10 g / L NaCl and 59.9 g / L Na ₂ SO ₄ ) , determined its consumption for the complete extraction of metal from the sorbent; at the outlet of the column, the volume of the eluate (V _i ), the nickel content in it (C $\genfrac{}{}{0ex}{}{\text{i}}{\text{Ni}}$ ) From the data given in the table, it follows that part of the eluate concentrate (the first 1.5 column volumes, 180 ml) in terms of nickel content (15.7 g-ion / l) corresponds to the composition of the commercial electrolyte given above / 16 /; the addition of 4.5 g of boric acid to obtain a marketable electrolyte of a given composition in all its components makes it possible to return 56% of sorbed-desorbed nickel to the main production, bypassing additional processing stages to obtain dry reagents. The rest of the eluate (780 ml) with C _Ni ~ 2.8 g / l is used as a ready-made eluent solution for processing a new portion of Ni-resin to obtain a marketable electrolyte of a given composition. The resin in the Na form is washed with water and again used to trap nickel ions from the wash water.

(112,5 + 56,9). В результате получают 180 мл (1,5 объема колонки) элюата концентрата с C_Ni= 23,5 г-ион/л, что соответствует концентрации никеля в товарном электролите нанесения никеля на цинковые отливки, имеющего состав /17/, г/л:
Сернокислый никель NiSO₄ • 7H₂O - 112,5 (23,5 г-ион/л Ni²⁺)
Сернокислый натрий Na₂SO₄ - 112,5
Хлористый аммоний - 22,5
Борная кислота - 15
К этому объему элюата-концентрата (180 мл) добавляют 4,05 г хлористого аммония и 2,7 г борной кислоты; с полученным товарным электролитом возвращают в гальваническую ванну 94,2% сорбированного-десорбированного никеля. 240мл (2 объема колонки) бедного по металлу элюата (C_Ni ≈ 1,1 г-ион/л) используют в качестве элюента для снятия никеля с новой порции насыщенного сорбента. Смолу в Na-форме после промывки водой вновь используют для сорбции никеля из промывных вод.Example 1. The desorption of Nickel from a saturated sorbent KU-2 is as follows. An eluting solution was passed through a layer (120 ml) of Ni-resin containing 4.5240 g of nickel ion nickel with

(112.5 + 56.9). The result is 180 ml (1.5 column volumes) of the eluate of the concentrate with C _Ni = 23.5 g-ion / l, which corresponds to the concentration of nickel in a commercial electrolyte for applying nickel to zinc castings, having the composition / 17 /, g / l:
Nickel sulfate NiSO ₄ • 7H ₂ O - 112.5 (23.5 g-ion / l Ni ²⁺ )
Sodium sulfate Na ₂ SO ₄ - 112.5
Ammonium Chloride - 22.5
Boric acid - 15
To this volume of the eluate concentrate (180 ml), 4.05 g of ammonium chloride and 2.7 g of boric acid are added; with the obtained commercial electrolyte, 94.2% of sorbed-desorbed nickel is returned to the plating bath. 240 ml (2 column volumes) of a metal-poor eluate (C _Ni ≈ 1.1 g-ion / l) is used as an eluent to remove nickel from a new portion of a saturated sorbent. The resin in the Na form after washing with water is again used to sorb nickel from the washings.

Example 2. To obtain a metal component and a salt component of a salable nickel plating electrolyte composition / 18 /, g / l:
Nickel sulfate NiSO ₄ • 7H ₂ O - 200 - 240 (41.8 - 50.2 g-ion / l Ni ²⁺ )
Sodium sulfate Na ₂ SO ₄ • 10H ₂ O - 100 - 150
Sodium Chloride - 10 - 15
Boric acid - 20
through 120 ml of KU-2 Ni-resin containing 5.8368 g of nickel ion, an eluting solution of 145.3 - 187.5 g / l Na ₂ SO ₄ and 10 - 15 g / l is passed at 40 - 45 ^o C NaCl. To 120 ml (one column volume) of the eluate concentrate containing 44.9 g-ion / l of nickel, 1.2 g of boric acid is added, with the resulting commercial electrolyte 87.1% of the sorbed-desorbed metal is returned to the electrolytic bath. Poor eluates (C _Ni ≈ 1-2 g-ion / L) are reused. KU-2 resin in Na-form is washed with 1-2 volumes of water and is again used for sorption of nickel ions from wash water.

Example 3. To obtain a metal component and a salt component of a commodity electrolyte of brilliant copper plating having the composition / 18 /, g / l:
Copper sulfate CuSO ₄ • 5H ₂ O - 100 - 125 (25.5 - 31.8 g-ion / l Cu ²⁺ )
Sodium sulfate Na ₂ SO ₄ • 10H ₂ O - 45 - 60
Ammonium sulfate - 45 - 60
Ethylene diamine - 40 - 60
an eluent solution containing 113 - 126 g / l ammonium sulfate is passed through a layer of Cu-resin KU-2 in a 120 ml column containing 6.4360 g-copper ion; to 180 ml (1.5 column volumes) of the eluate concentrate (C _Cu = 25.5 - 30.1 g-ion / l) add 8.1 - 10.8 g of Na ₂ SO ₄ and 7.2 - 10, 8 g of ethylenediamine; 71–84% of the metal is returned to the main production with the obtained commercial electrolyte. The poor eluate (3-4 column volumes with C _Cu = 0.2-0.5 g-ion / L) is reused to elute copper from a new portion of the sorbent after it is saturated. KU-2 cation exchanger in the NH ₄ form is used for sorption of copper ions from wash water.

Example 4. To obtain a metal component and a salt component of a commercial electrolyte of a semi-brilliant copper coating composition / 16, p. 113 / g / l:
Copper sulfate CuSO ₄ • 5H ₂ O - 90 (22.9 g-ion / l Cu ²⁺ )
Ammonium nitrate - 40
Ammonium sulfate - 80
22% ammonia - 180 ml / l
An eluting solution containing 40 g / l ammonium nitrate and 127 g / l ammonium sulfate is passed through a KU-2 Cu-resin layer in a 120 ml column containing 6.2270 g of copper ion. To 1.9 column volumes (228 ml) of the eluate concentrate (C _Cu = 27.1 g-ion / L, add 41 ml of 22% ammonia; 99.2% of the sorbed-desorbed metal is returned to the main production with the resulting commercial electrolyte Two volumes of a column of lean eluate (C _Cu ≈ 0.2 g / L) are used as the eluting solution repeatedly. The resin in the NH ₄ form, after washing with water, is used to sorb copper ions from the washings.

Example 5. To obtain a metal component and a salt component of a commercial zinc electrolyte composition / 16, p. 82 /, g / l:
Zinc sulfate ZnSO ₄ • 7H ₂ O - 120 - 150 (27.1 - 34.1 g-ion / l Zn ²⁺ )
Dispersant NF - 50 - 100 ml / l
Ammonium Chloride - 200 - 250
Acetic acid (or ammonium acetic acid) - 30 - 35
an eluting solution of 200-250 g / l ammonium chloride and 55-69 g / l ammonium sulfate is passed through a KU-2 Zn-resin layer in a 100 ml column containing 6.2570 g-zinc ion; to 200 ml (two column volumes) of the eluate concentrate (C _Zn = 30.8 g-ion / l) add the calculated amount of NF dispersant, acetic acid (or ammonium acetic acid) and 98.5% of the sorbed-desorbed metal is returned to the main production . A poor eluate (200 ml, C _Zn = 0.5 g-ion / L) is used as an eluent to obtain a marketable electrorelate. The sorbent KU-2 in the NH ₄ form after washing with water is used to sorb zinc ions.

 Thus, the proposed method allows without additional processing of eluate concentrates to return to the main production in one cycle 56 - 99% sorbed-desorbed metal, simplifies the design of a closed waste-free (metal) galvanic production and environmental problems.

Sources of information:
1. Ionites in non-ferrous metallurgy ./// Ed. K.B. Lebedev. M .: Metallurgy. 1975.

 2. A.S. N 1,458405, 1989; A.S. N 1475952, 1989.

 3. US patent N 3380804, 1969.

 34. Ion exchange in metallurgy and wastewater treatment. // Alma-Ata, 1972 (Kazmekhanobr. Syu. N 10), p. 39.

 5. Extraction and sorption in the metallurgy of nickel, cobalt and copper. M.: Tsvetmetinformation. 1970, p. 945.

 6. Materials of the All-Union meeting on wastewater treatment of chemical fiber enterprises. Kiev. Gosgorizdat. 1963. p. 183.

 7. V. A. Derevyankin et al. // University News. Ser. "Non-ferrous metallurgy". 1981, N 3, p. 47 - 50.

 8. I.N. Plaksin et al. // DAN SSSR, 1959, v. 129, No. 6, p. 1351; t. 124, No. 1, p. 153 - 154.

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 10. Wastewater and circulating water treatment of non-ferrous metallurgy enterprises. // M., Metallurgy, 1971 (Kazmekhanobr. Sat. N2), p. 74.

 11. I.V. Khanov et al. // Abstracts of the report. All-Union Conf. "Chemistry and technology of rare, non-ferrous metals and salts." Frunze, 1986, p. 56.

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 13. Electroplating. Reference // Ed. A.M. Ginberg et al. M .: Metallurgy, 1987, p. 702.

 14. S.M. Balakin et al. // Ion exchange materials in the national economy. M.: Publishing House of VDNH USSR, 1977, p.75.

 15. A.E. Orenshtein // Environmental protection and safety in galvanic production. Seminar materials. M .: 1982, p. 65.

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 17. Ref. Guide to Electroplating // Ed. V.I. Lightyear. M.: Metallurgy, 1972, part 1, p. 396.

 18. Reference chemist. M. - L .: Chemistry, vol. V, 1966, p. 944 - 946.

Claims (3)

 1. A method of desorption of a metal, comprising treating a saturated sorbent with an eluting solution and washing with water, characterized in that the desorption of the metal is carried out with an eluting solution of composition and concentration identical to the composition and concentration of the salt component of a commodity electrolyte, fortified with an equivalent amount of sodium salts in a commodity electrolyte and ( or) ammonium with an anion of the same name as the anion of the metal-containing component of a commodity electrolyte.  2. The method according to p. 1, characterized in that the salt component of a commercial electrolyte contains sodium and (or) ammonium salts.  3. The method according to claim 1, characterized in that the poor (metal) eluates are used as an eluting solution.

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