RU2110323C1 - Catalyst for extraction of copper from spent solutions and method of its production - Google Patents

Abstract

FIELD: production of catalysts, applicable for extraction of copper from solutions, industrial sewage and sewage water. SUBSTANCE: catalyst contains 0.5 to 5.0 mass percent of copper on carbon carrier having a high specific surface. This catalyst is obtained by precipitation of metal on carrier by impregnation of carrier with a solution of complex copper salt - diammine hypophosphite dihidrate with a subsequent heat treatment at 90 to 150 C for 10 to 30 min. EFFECT: enhanced efficiency. 2 cl, 1 tbl

Description

 The invention relates to a technology for producing catalysts, and can be used to extract copper from solution, industrial effluents and wastewater.

 Known catalyst based on the acetate complex of palladium 11 [1] for the extraction of copper from alkaline waste solutions using a reducing agent - carbon monoxide.

 The main disadvantages of the catalyst are the use of precious metals and toxic carbon monoxide.

 A known catalyst is sheet copper, in the presence of which copper ions are reduced from spent solutions with formalin [2].

 Disadvantages: shallow degree of purification; the need for heating solutions and equipment for this; the difficulties associated with the fact that copper is released in the form of fine particles, which to separate from the pulp is a very laborious process.

 Closest to the proposed catalyst is considered, consisting of granular material with a large specific surface area, containing a noble metal in the form of a film on the surface of granules, occupying more than 50% of this surface [3].

 The specified catalyst is used for the separation of metals from spent copper - and / or nickel-containing electrolytes, in the presence of a complexing agent and a reducing agent - formalin.

 The main disadvantage is the high cost of it and technologies based on its use.

 The problem of creating an economical catalyst, and with its help, cheaper technology for the extraction of metals from solutions. For this purpose, a catalyst based on finely dispersed copper deposited on a granular porous material, with a ratio of components, wt.%: Copper of 0.5-5.0; carbon carrier - the rest.

2,087; 1,808; 1,278 для меди).Quantitative analysis of the copper content in the solid residue after burning a portion of the catalyst and its oxidative dissolution was carried out by iodometric titration, with an accuracy of ± 0.2% (0.5 g sample). The phase composition was determined by x-ray diffraction by x-ray diffraction indices (

2.087; 1.808; 1.278 for copper).

Индексы дифракции наблюдались при увеличении содержания на носителе или при увеличении температуры его прокалки при изготовлении катализатора описанным ниже способом.The results of chemical analysis of the obtained samples of the catalysts correspond to the above% -mass ratios. Their phase analysis corresponded to the finely dispersed deposited phase in the absence of diffraction indices on the X-ray diffraction patterns, characteristic of particles with an average size of not more than 40 ±

Diffraction indices were observed with an increase in the content on the support or with an increase in its calcination temperature in the manufacture of the catalyst as described below.

As carbon granular materials, industrial activated carbons of various grades with a high specific surface (about 800 - 1200 m ² / g) and a total porosity of 0.6-1.5 cm ³ / g were used.

 A known method of preparing a catalyst "metal on a carrier" by treating the carrier with an aqueous solution of a metal salt, followed by drying, calcining and reduction with an aqueous solution of hydrazine hydrate, or in a stream of hydrogen for a long time [4].

Т. е. ионы Cu восстанавливаются до Cu^o за счет окисления гипофосфит - иона, H₂PO₂.The main disadvantages of the prototype are the complexity and multi-stage process, the use of toxic or explosive reducing agents, and the need for additional equipment for their supply to the reactor. The proposed catalyst is obtained by the method in which the carrier, previously calcined at 110-150 ^o C, to remove moisture adsorbed in it, is impregnated "by moisture capacity" with an aqueous solution of ammonium complex of copper hypophosphite, then dried and calcined at 90 - 150 ^o C, during 10-30 minutes, until the complex decomposes according to the reaction:

That is, Cu ions are reduced to Cu ^o due to the oxidation of the hypophosphite - ion, H ₂ PO ₂ .

 The resulting catalyst was washed with water (to remove by-products) and dried in air.

The specified ammonia complex of copper hypophosphite is obtained by dissolving 0.2-1.3 mol of CuSO ₄ • 5H ₂ O in 1 liter of distilled water and gradually adding 0.2-1.0 mol of calcium hypophosphite, Ca (H ₂ PO ₂ ) ₂ . The precipitated precipitate of calcium sulfate is filtered off, 0.8-5.2 mol of aqueous, 25% ammonia solution is added to the filtrate with cooling, and a dark blue aqueous solution of the ammonia complex is obtained, which is stable during storage for a long time [5] - diamminodihypophosphite dihydrite copper.

Example 1. 100 g of activated carbon brand AGM with a total pore volume of 0.60 cm ³ / g and S _beats . = 1070 m ² / g with stirring is introduced into 60 ml of a 1M aqueous ammonia solution of Cu (H ₂ PO ₂ ) ₂ containing 3.8 g of copper (in terms of metal). Impregnated "by moisture capacity", the support is dried in air at room temperature, or at 50 ^° C (to speed up drying) to remove water, then calcined in air at 120 ^° C for 15 minutes, cooled, washed with water, and dried.

Пример 2. Берут уголь марки СКТ-2 с суммарным объемом пор 0,7 см³/г и S_уд. = 1200 м²/г обрабатывают 70 мл 1М раствора по примеру 1, при 160^oC в течение 10 мин.The resulting catalyst, according to the analysis, contains: copper - 3.7 wt.%, (Theoretical 3.8 wt.%). The deposited phase is X-ray amorphous (hereinafter referred to as R.A.); the average particle size of copper is less than

Example 2. Take coal brand SKT-2 with a total pore volume of 0.7 cm ³ / g and S _beats. = 1200 m ² / g is treated with 70 ml of 1M solution according to example 1, at 160 ^o C for 10 minutes

: 2,087; 1,808; 1,278. Средний размер частиц более

Пример 3. Берут уголь марки КАД-иодный, обрабатывают при 150^oC в течение 10 мин. По данным РФА полученный катализатор рентгеноаморфен.The copper content in the resulting catalyst is 4.5 wt.% (Theory. 4.43%). The applied phase gives the following diffraction indices

: 2,087; 1.808; 1.278. Average particle size over

Example 3. Take coal brand KAD-iodine, treated at 150 ^o C for 10 minutes According to XRD data, the resulting catalyst is X-ray amorphous.

Example 4. According to the conditions of example 1, the treatment is carried out at 90 ^o C for 30 minutes The catalyst is X-ray amorphous.

 Examples with other parameters and processing conditions are summarized in the table.

однако имеет место неполное разложение комплекса (в промывных водах отмечено наличие ионов меди).As can be seen from the table, if the conditions for heat treatment of the carrier are not observed (Example 2), the average particle size of copper increases, which negatively affects the effect of copper extraction from solution (due to a decrease in catalytic activity, a decrease in the dispersion of the deposited particles). With a decrease in the calcination temperature (example 5), even with an increase in its time (example 6), the particle size of copper is about

however, there is an incomplete decomposition of the complex (the presence of copper ions is noted in the washings).

 A decrease in the copper content in the catalyst (Example 7) is undesirable, because its activity decreases, and an increase (Example 8) leads to the formation of coarse particles and a decrease in the total pore volume. The results of checking the activity of the catalyst samples obtained by the examples described above are summarized in the table. For purification (copper extraction), alkaline spent solutions of chemical copper plating were taken containing a complexing agent (Trilon B) and formalin.

The extraction of copper is carried out as follows: take 1 g of the obtained catalyst - "copper on the carrier" and immersed in a glass with 1 l of the processed solution of the composition, g / l:
CuSO ₄ • 5H ₂ O - 15.0
Trilon B - 30.0
NaOH - 15.0
KCNS - 0.02
add 20 ml of a 37% solution of (aqueous) formalin and mix at room temperature for 30-60 minutes until the solution is completely discolored, which indicates the completion of the process of recovery of copper ions and the precipitation of its dispersed particles on a carrier.

As can be seen from the table (see columns NN 7–9), a catalyst containing 0.5–5.0 wt% copper on a support obtained by impregnating a carbon support with an aqueous solution of copper diamminodihyposphite dihydrate under effective heat treatment at 90–150 ^o C for 10 to 30 minutes

The catalyst obtained by the proposed method is not inferior in terms of the degree of copper extraction from solutions to known catalysts (the residual content of Cu ²⁺ is 0.1 - 0.2 mg / l, while it is economical (does not contain expensive platinum group metals), the catalyst preparation method simple (only two stages), available reagents, low temperatures are used.

Claims (1)

1. The catalyst for the extraction of copper from spent solutions containing highly dispersed metal particles on a carbon carrier, characterized in that the metal contains copper with an average particle size of less than

in the following ratio of components, wt.%:
Copper - 5.0
Media - Other
2. A method of producing a catalyst for the extraction of copper from spent solutions by impregnating the carrier with a solution of a metal salt, followed by drying and heat treatment, characterized in that the complex salt is used as a metal salt - copper diamminodihypophosphite dihydrate in an amount providing a copper content of 0.5 - 5.0 wt.%, With an average particle size of less than

and heat treatment is carried out at 90 - 150 ^o C for 10 to 30 minutes

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