Method of extracting cerium

FIELD: chemistry.

SUBSTANCE: invention relates to methods of extracting cerium (IV) from sulphate solutions by extraction and can be used for concentration of cerium (IV) from ore, processing solutions with a complex salt composition and for analytical purposes. Extraction is carried out from 0.5-2.0 M sulphate solution with 0.32% 2-methyl-8,9-dihydro[1,2,4]triazolo[1,5-α]quinazolin-6(7H)-one solution, dissolved in methylene chloride. The phase contact time is 15 min. After demixing, the organic phase is separated and re-extraction is performed.

EFFECT: conducting the process in milder conditions without using concentrated acid solutions and high output of cerium.

1 dwg, 2 ex

 

The invention relates to a method of extraction of cerium(IV) sulphate solutions by the method of extraction and can be used for concentration of cerium(IV) from ores, production of solutions of complex salt composition and analytical purposes.

As extractants for the extraction of cerium used naphthenic acid (RU 2320738, C22B 59/00), tributyl phosphate (EN 2293134, C22B 59/00).

The extraction of cerium naphthenic acid, dissolved in decane, the output of metal is 73,5% (Devyatkin M. Extraction of cerium naphthenic acids // Vestnik of MSTU, 2007. - V.10, №4. - S-620).

For the extraction of cerium tributyl phosphate reservation oxidation of cerium to the tetravalent state for satisfactory separation from other lanthanides. The disadvantage of the use of tributyl phosphate as an extractant is an expensive method, using aggressive concentrated solutions of acids, duration and multi-stage processes of extraction and re-extraction (Skorik N.A. About the extraction of tetravalent cerium from nitric acid solutions by tributyl phosphate/ NA Skorik, A.G. Sakovich, IV Kotlyarova // Ukr. neorg. chemistry, 1980. - V.25, No. 10. - S-2778).

The method for extracting rare earth elements (REE) from phosphogypsum, including the processing of phosphogypsum with a solution of sulfuric acid, filtering and highlighting of the floor, the military solution is the sum of the REE (Pushkin GY and other Use of ion exchanger KMDF to highlight REE of phosphate and sulfate solutions. Problems of atomic science and technology. Series: Chemical problems of nuclear power, 1992, B.5, p.77-80). REE allocate adsorption on the ion exchanger KMDF. The degree of extraction does not exceed 71%. The disadvantage of this method is the low degree of extraction of cerium, the high cost of ion exchanger and the long duration of the process.

After processing of phosphogypsum with sulfuric acid according to the method described in the patent of the Russian Federation (No. 2109686, 1998, C01F 17/00), rare earth elements are extracted from the resulting solution in the form of fluorides, which are situated fluoride-hydrogen acid. The degree of REE extraction from a solution of 76%.

There is a method of extraction of cerium(IV) from 6-7 M solution of nitric acid and 1 M potassium bromate 0.3 M solution of tri-n-octylamine in chloroform (Determination of cerium in steels with preliminary extraction with trioctylamine / LI Kharlamova [and other] // Plant. lab., 1979. - N II. - S-990).

The disadvantages of this method is the use of aggressive environment 7 M HNO3in the presence of an oxidant 1 M KBrO3The method has sufficient selectivity and long enough.

The claimed invention is intended to expand the Arsenal of extractants used for the extraction of cerium.

The technical result consists in carrying out the process in a milder the conditions not using concentrated solutions of acids, increasing the yield of cerium in extraction and increase the selectivity of the process.

The technical result is achieved by the fact that the process of extraction of cerium(IV) are from 0.5 to 2.0 M sulfate solutions 0,32%solution of 2-methyl-8,9-dihydro[1,2,4]triazolo[1,5-α]hinzelin-6(7H)-she dissolved in methylene chloride, the contact time of the phases is 15 minutes, after separation the organic phase is separated and are reextraction.

Figure 1 presents a table showing the effect of the concentration of H2SO4the degree of extraction of ions of Ce(IV).

Example 1. In the separating funnel was placed 10 ml sulfate solution containing 6 mg/ml cerium(IV), and 10 ml of 0.32%solution of 2-methyl-8,9-dihydro[1,2,4]triazolo[1,5-α]hinzelin-6(7H)-she dissolved in methylene chloride. The experiments were carried out at various concentrations of H2SO4(0,50 M 1,00 M 2,00 M) (table), the contact time of the phases was 15 minutes.

After separation the organic phase is separated and are reextraction. The cerium content is determined in reextract spectrophotometric method at λ=310 nm.

As follows from table (figure 1), with the highest degree of extraction is observed in the application of 0.50 M solution of sulfuric acid and is 89,28%.

Example 2. In the separating funnel was placed 10 ml of 0.5 M sulfate solution containing 0.5 mg/ml of the Church is I(IV). Add iron, calcium, zinc, manganese, copper, yttrium. Add 10 ml of 0.32%solution of 2-methyl-8,9-dihydro[1,2,4]triazolo[1,5-α]hinzelin-6(7H)-she dissolved in methylene chloride. The solution is thoroughly mixed. The contact time of the phases is 15 minutes.

After separation the organic phase is separated and are reextraction. Atomic absorption spectrometry revealed that reextract contained 92.7% of cerium, of 1.6% iron, 1.5% calcium, 0.8% zinc, 0.2% manganese, 0.1% cu, 3.1% of yttrium.

The method of extraction of cerium, which consists in the fact that the conduct of the process of extraction of 0.5-2.0 M sulfate solution of 0.32%solution of 2-methyl-8,9-dihydro[1,2,4]triazolo[1,5-α]hinzelin-6(7H)-she dissolved in methylene chloride, at the time of the contact phase of 15 min, after separation of the phases the organic phase is separated and are reextraction.



 

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5 tbl, 5 ex

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