SU1444300A1 - Method of purifying flotation fluorite concentrates - Google Patents

Abstract

The invention relates to chemical technology, in particular to methods for cleaning flotation fluorite concentrates. Aqueous suspension of fluorite concentrate containing,%: CaF 91.53; CaCOj 2.77; SiOj 2.10, at a ratio of T: W 1: (O, 5-10), is treated with 10-45% hexafluorosilicic acid, taken in 2-5-fold excess in excess of cTeidiometric amount, at room temperature for 20 -60 min with mechanical stirring. The solid product is separated and leached with a 50 g / l sodium hydroxide solution at and at a pressure of 8-10 atm for 60 minutes. The pulp is filtered, the concentrate is washed with water, and dried. The invention allows to increase the degree of purification of the concentrate from calcium carbonate impurity from 56-72 to 75-88% and, in addition, allows to reduce the cost of the process due to the use of r-exafluorcremic acid, which is a production waste. 1 tab. § WITH

Description

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The invention relates to chemical technology, in particular to methods for purifying flotation fluorite concentrates, and can be applied in the preparation of high-quality fluorite concentrates.

The purpose of the invention is to increase the degree of purification from calcium carbonate.

Example. Aqueous suspension of fluorite concentrate containing,%: CaF 91.53; CaCO 2.77; SiOj 2.10, with a T: W ratio of 1: 1, is treated with 25% hexafluoro silicic acid, taken in a 5-fold excess over a stoichiometric amount, at room temperature for about 60 minutes with mechanical stirring. The solid product is separated and leached with a 50 g / l sodium hydroxide solution at 175 ° C and a pressure of 8-10 atm for 60 minutes. The pulp is filtered, the concentrate is rinsed with water, dried and the content of the main components is determined by chemical analysis,%: CaF 96.43; CaCO 0.33; SiO 0.48. The degree of purification from caso, 88%.

 The table shows the dependence of the degree of purification on CaCO, on the ratio 1: W and the amount of hexafluorosilicic acid.

From the data in the table it follows that the use of an amount of less than 2-fold of the stoichiometrically necessary excess does not lead to an increase in the degree of purification from calcium carbonate in comparison with the method of the prototype, and the increase in the amount

5 0 5;

Q

Q

A 5-fold surplus is economically disadvantageous, since it leads to an over-expenditure of sf. The increase in the ratio of the solid phase and the liquid and water. a suspension of fluorite concentrate higher than 1:10 is impractical because it does not lead to a further increase in the degree of purification from calcium carbonate. When the T: L ratio is lower than 1: 0.5, the mixing of the reaction mixture is difficult and the degree of purification does not increase.

The invention allows for improvement. the degree of purification of the concentrate from the calcium carbonate impurity is from 56-72 to 75-88% and, in addition, it makes the process cheaper by using hexafluorosilicic acid, which is a waste product, instead of expensive ammonium bifluoride.

Claims (1)

Invention Formula . The method of purification of flotation orite concentrates, which includes treating them with a solution of fluorine-containing reagent, separating the solid phase and autoclaving leaching from the last silica in an alkaline medium under heating and pressure, which differs. In order to increase the degree of purification from calcium carbonate, hexafluorosilicic acid is used as fluorine-containing acid in 2-5-fold excess over stoichiometry and the aqueous suspension is subjected to treatment. Zium fluorite concentrate with T: W 1: 0.5-10. Table continuation Pr me.chanie. The content s of the original concentrate, Z GaF, 91,53; Caso, 2.77; SiOj 2,10.J