SU1108077A1 - Method of concentrating boron from solutions - Google Patents

Abstract

1. METHOD FOR CONCENTRATING BORON FROM SOLUTIONS by sorption using as a sorbent a copolymer of styrene with divinylbenzene with Tris (oxymethyl) aminomethane functional groups followed by desorption of boron with a mineral acid solution, characterized in that, to increase the concentration of boron, sorption is carried out on the sorbent pretreated with methanol, and desorption with a solution of sulfuric acid. 2. A method according to claim 1, characterized in that the sorption is carried out on a sorbent pretreated with methanol, taken in an amount of 2-3 volumes per 1 volume of sorbent within 1-2 hours. 3. A method pop. 1 and 2, characterized in that the desorption of SLs is 0.3-0.4 n. a solution of sulfuric acid at a volume ratio in the solution HjSO. : sorbent equal to

Description

The invention relates to the concentration and separation of elements for the following mass spectral detection and can be used in analytical chemistry for quantitative chemical analysis. There is a known method of boron separation using a two-step ion-exchange process. The test solution is successively passed through a cation exchanger (Dowex - 50) to separate it from the cationic component, and then through anion exchanger 1. The disadvantage of this method is the incomplete distribution of boron. The closest to the proposed technical essence and the achieved result is a method of concentrating boron from solutions by sorption using styrene-divinylbenzene copolymer with functional groups of tris (oxymethyl) aminomethane as a sorbent followed by desorption with hydrochloric acid 2. The disadvantage This method is known to have a low boron recovery rate (70%). The purpose of the invention is to increase the concentration of boron. The goal is achieved by the proposed method of concentrating boron from solutions by sorption using as a sorbent a copolymer of styrene with divinylbenzene with tris (oxymethyl) aminomethane groups pretreated with methanol followed by desorption of boron with sulfuric acid. In this case, sorption is carried out on a sorbent pretreated with methanol, taken up in an amount of 2-3 volumes per 1 volume of sorbent for 12 hours. Desorption is carried out in the range of 0.3-0.4 n. sulfuric acid solution at a volume ratio of solution. : sorbent equal to (2-3): 1. The method is carried out as follows. The sorbent with tris- (hydroxymethyl) amino methane is treated with methanol (three volumes) for 1-2 hours. The column is filled with the treated sorbent, then the test solution is passed. Treatment with methanol (swelling of the net copolymer) provides favorable steric conformation of polymer chains containing tris (oxymethyl) aminomethane groups in the complexation reaction with boric acid during sorption. Column sizes are selected c. Depending on the boron content in the analyzed solution. Elution was performed at 0.30, 4 n. sulfuric acid. The use of sulfuric acid (for example, compared with hydrochloric acid, with elution of which the degree of absolute concentration is slightly worse and is 0.01), is due to the fact that for subsequent isotopic analysis of boric acid is subjected to an esterification reaction with an excess of methanol in the presence of dehydrating . Ether couples are sampled by freezing with liquid nitrogen into glass ampoules for mass spectral detection of the boron ihtope composition. Sulfuric acid | remaining in the sample during evaporation of the eluate, performs the role of a water-removing agent in a vacuum unit, and also ensures the purity of the reaction products. The degree of absolute concentration in the case of aluminization is 0.3-0.4 n. reaches 0.004 with 98-100% boron recovery. The use of more concentrated H2SO4 does not benefit in the degree of absolute concentration and complicates the subsequent stage — evaporation of the solution. An example of a 1.0.2 liter solution containing 10 mg / liter V is filtered through a column of sorbent (40 cm long, 0.25 cm in diameter), previously washed with 0.1N. NaOH. Filtration rate of 1 MP / min. Boron washed out 7 ml of 0.4 n. in the form of boric acid. The degree of extraction of boron 70%. PRI mme R 2. 0.5 liter of oceanic water containing 4.5 mg / liter of V is filtered through a column with a sorbent pretreated with 4-6 ml of methanol (within 1-2 hours). Column length 40 cm, diameter 0.25 cm. Filtration rate 1 ml / min. Thief washed out 0.4 n. Hjso. The degree of extraction of boron 98%. The resulting boric acid reacts with 0.8-1 ml of methanol (in a vacuum unit) to boron methyl ether, the vapors of which are taken by freezing with liquid nitrogen into glass ampoules; the ampoules are hermetically sealed and, thus, the test sample is ready for

subsequent mass spectral gas-phase analysis of the isotopic composition of boron.

Example 1 liter of groundwater containing 0.45 mg / liter of B is filtered through a column of sorbent pretreated with 4-6 ml of methanol (within 1-2 hours). Column length 40 cm, diameter 0.25 cm. Filtration rate: 1 ml / min. Boron washed out 4 ml 0.4 n. . The degree of extraction of boron 97%. Further manipulations with the boric acid thus obtained are similar to example 2.

PRI me R 4. 20-30 mg tourmaline

containing 8-12%, decompose 2

by melting a sample of the mineral with NaOH and precipitating iron and aluminum hydroxides. Then the solution is filtered through a column of resin (diameter 0.25 cm, length 40 cm) at a rate of 1. ml / min, after which the resin is washed with 50 ml of distilled water. Then boron washed out with 1 ml of 0.4 n. ., boron recovery rate of 96%.

The table shows the comparative data on the concentration of boron by known and proposed methods.

Without treatment with methanol

(prototype) Processed with methanol

Table continuation

96

0,0044

1: 3,5 j11080 As follows from the presented data, the degree of absolute concentration of boron by the proposed method reaches 0.004 with 98-100% of the degree of extraction of boron. 5 The technical and economic effect of the proposed method is due to an increase in the degree of extraction and concentration of boron, which ensures the accuracy of the subsequent analysis of the analyzed objects; the ability to isolate boron from dilute solutions, for example, natural waters, and rapidity, which is provided by reducing intermediate stages (evaporation of solutions) and alone, in the sorption process.

Claims (3)

1. METHOD OF CONCENTRATION OF BORON FROM SOLUTIONS by sorption using a copolymer of styrene with divinylbenzene with functional groups of tris (oxymethyl) aminomethane as a sorbent followed by desorption of boron with a mineral acid solution, characterized in that, in order to increase the concentration of boron, sorption is carried out on sorbent pretreated with methanol, and desorption with a solution of sulfuric acid. 2. The method according to π. 1, characterized in that the sorption is carried out on a sorbent pretreated with methanol taken in an amount of 2-3 volumes per 1 volume of sorbent for 1-2 hours 3. The way popp. 1 and 2, characterized in that the desorption is 0.3-0.4 N. sulfuric acid solution at a volume ratio of a solution of H ₂ S0 ₄ : sorbent equal to (2-3): 1. SU „„ 1108077 1 1108077