SU387275A1 - METHOD OF ANALYZING EXTRACTORS BASED ON NEUTRAL AIR MIXTURE - Google Patents

Description

one

This invention relates to analytical chemistry, in particular, to the control of the extraction processes of rare scattered elements.

At present, spectrophotometric methods are used to analyze TBP-based extractants with the addition of alkyl phosphoric acids (e.g. D2EHPA) in an inert solvent (usually 1kerosene), which require the use of sophisticated instruments and highly skilled performers.

The purpose of the invention is the development of an accelerated method for the analysis of extractants, which are a mixture of neutral phosphoric and alkylphosphoric acids, which is not useful for the operational control of production.

According to the proposed method, two series of measurements of the dielectric constant (DP) of the extractant based on neutral ethers of phosphoric acid (for example TBP) and alkyl phosphoric acids (for example D2EHPA) are carried out: 1) free extractor; 2) spent with a solution of nitric acid with a concentration of 0.75-1.5.

DP neutral esters of phosphoric acid and alkylphosphoric acids are in the range of 7-9, then: as the DP of the solvent (kerosene) is significantly less - 2. Thus, the first measurement of the DP gives the content of the sum of extracting substances in kerosene.

At Obs; an extra agent with a solution of nitric acid of a certain moderate concentration of TBP 1 transforms into nitric acid complexes, the DP of which is significantly higher than that of the original extractgeite. Alkyl phosphoric acids do not absorb nitric acid from its solutions of moderate concentration. So

Thus, the second of the measurements of DP gives the TBP content in the extractant, which is proportional to the increment of the PD extractant after treatment with nitric acid. The content of alkylphosphoric acid is from the difference.

The proposed method allows the analysis of extractants using an easy-to-use dielectric permittivity meter (electrical capacitance).

Example. To determine the content of D2EHPA and TBP in a kerosene-based extractant, a series of standard mixtures of individual extras with kerosene and

Two graphs of DP extra dependencies on the content are plotted. A series of standards based on TBP is treated with a 1 M solution of nitric acid with an organic: 1 water ratio of 1: I and based on measurements

The DP builds a tertiary plot of the increment of the DP extractant on the TBP content. (

A sample of an extractant of unknown composition after the reaction of absorbed components and washing with water is subjected to measurement of DP, then treated with 1 M solution of nitric acid at an organic: aqueous ratio 1: 1 AND "HOSib" measure DP. PIP: DP increase by the third (Graph TBP. According to the found TBP content, the corresponding DP value is found according to the calibration schedule. This value is subtracted from the DP extractant ino value to the first measurement and 1PO calibration chart for D2EHPK to find the content last.

In a wide range of concentrations of neutral esters of phosphoric acid and alkyl phosphoric acids, the additivity of DP extractant remains and the increment of DP TBP increment after treatment with nitric acid on the content of alkyl phosphoric acid remains low.

Subject invention

Method of analysis. E1Kstrague: nto (in based on a mixture of neutral phosphoric acid esters and alkyl phosphoric acids in inert dilutions on the dielectric constant,

characterized in that, in order to speed up the analysis and differentiated determination of the test substances, the extractant is treated with a solution of 0.75-1.5 mol / l before measuring and the increment of its dielectric value is measured .portsiooealno.e content of neutral ether, which is compared with the dielectric constant of the raw extractant.