Method of extracting silver ions from low-concentration silver nitrate solutions

FIELD: chemistry.

SUBSTANCE: method includes passing the solution through polymer fibre for sorption of silver ions. After passing the solution, silver ions contained in the fibre are reduced to a metal state with 0.02 M aqueous solution of a mixture of ascorbic acid with glucose in ratio of 1:9. Silver metal is then extracted by burning the silver-containing fibre in an air atmosphere at temperature of 450-500°C, followed by washing the formed silver reguli.

EFFECT: recovering silver ions from industrial waste water, improved method of extracting silver from process solutions used when producing textile materials with antimicrobial properties.

2 ex

 

The invention relates to a method for selection of silver ions from dilute solutions based on sorption of silver ions polymer fiber containing thioamide group, followed by reduction of silver ions to metal, and can be used in resource-saving technologies, aimed at the selection and regeneration of scarce expensive component of silver ions from wastewater industries.

The method for extracting silver ions from dilute solutions of silver nitrate, comprising passing the solution through a polymer fiber (see e.g. U.S. patent No. 3821137, C08b 23/00, publ. 28.06.1974 year).

The disadvantage of this method is the lack of conditions in which the subsequent allocation of sorbed silver, and it is not the type of reductant reagent, the composition of the recovery system, its concentration, the water ratio processing fibers containing silver ions, and temporary conditions recovery of silver ions in the phase of fiber, as well as conditions for the allocation of metallic silver (temperature combustion fiber containing metallic silver).

The basis of the invention is tasked to improve the method of extraction of silver ions from dilute aqueous solutions of silver salts and to provide the division of silver from technological solutions, used in obtaining textile materials with antimicrobial properties.

The problem is solved in that in the method of extraction of silver ions from dilute solutions containing silver ions, comprising passing the solution through a polymer fiber, the restoration of silver to the metallic state conduct 0.02 M aqueous solution of a mixture of ascorbic acid with glucose at a ratio of 1:9, and the selection of metallic silver is made by burning silver-containing fibers in an atmosphere of air at a temperature of 450-500°C, followed by washing the resulting Korolkov silver.

Since the restoration of silver to the metallic state conduct 0.02 M aqueous solution of a mixture of ascorbic acid with glucose at a ratio of 1:9, and the selection of metallic silver is made by burning silver-containing fibers in an atmosphere of air at a temperature of 450-500°C, followed by washing the resulting Korolkov silver, provides a selection of silver from the technological solutions used in obtaining textile materials with antimicrobial properties.

The extraction of silver ions from dilute solutions of silver nitrate is as follows.

Example 1

50 g chemisorptive fiber containing tion the derivative group in the amount of 2.8 mEq/g, placed in the column and passed through it at room temperature a solution of silver nitrate with a concentration of 4.3 g/l at a speed bandwidth solution of 200 ml/hour until the breakthrough, which is judged by the content of silver in the filtrate. The filtrate is analyzed by the content of silver ions by the above method.

For recovery of silver ions contained in the fiber, the fiber is placed in a 0.02 M aqueous solution of a mixture of ascorbic acid with glucose at a ratio of 1:9, the water ratio of 100 ml/g and maintained at a temperature of 100°C for 120 minutes. At the end of processing fiber drained, washed and dried at a temperature of 100°C. Metallic silver produce by burning fibers in a porcelain crucible in a muffle furnace in air atmosphere at a temperature of 450°C for 30 minutes. The Regulus of silver weighed after washing. The silver content is 290 mg.

Example 2

A solution containing 4 g/l of silver nitrate, 0.15 g/l of iron nitrate, 20 g/l of copper nitrate, 0.0025 g/l of zinc nitrate was passed at room temperature through chemisorption fiber containing 2.5 mEq/g thioamide groups.

The composition of the filtrate (iron nitrate Fe(NO3)3- 0.15 g/l, copper nitrate Cu(NO3)2- 20 g/l, zinc nitrate (Zn(NO3)2- 0/0015 g/l) confirms the selectivity of silver extraction data chemisorptive fiber is in the above-described conditions.

Recovery of silver ions contained in the fiber, conduct, placing chemisorptive fiber in a 0.02 M aqueous solution of a mixture of ascorbic acid with glucose at a ratio of 1:9, the water ratio of 100 ml/g, and incubated at 90°C for 150 minutes. At the end of processing fiber drained, washed and dried at a temperature of 100°C. Metallic silver produce by burning fibers in a porcelain crucible muffle furnace in air at 500°C for 20 minutes. The Regulus of silver weighed after washing. The content of silver is 250 mg

Technical control process for the recovery of silver from spent process solutions provide titrimetric, to which 5 ml of the filtrate add 1 ml salesonline alum (concentration 40 g/l) and titrated with constant stirring 0.1 M solution of Redonda potassium KSCN until yellow. The calculation of the degree of extraction of silver ions (R) is carried out by the formula:

R=100-(ν1-ν2)1080ν1,%,

where ν1the number of KSCN solution, followed by titration of the working samples technological rest the RA, ml;

ν2the number of KSCN solution, followed by titration of the working sample of the effluent, Jr.

The method of extraction of silver ions from dilute solutions of silver nitrate, comprising passing the solution through a polymer fiber for sorption of silver ions, characterized in that after passing a solution of silver ions contained in the fiber, reduced to the metallic state of 0.02 M aqueous solution of a mixture of ascorbic acid with glucose at a ratio of 1:9, and produce metallic silver by burning silver-containing fibers in an atmosphere of air at a temperature of 450-500°C, followed by washing the resulting Korolkov metallic silver.



 

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