RAPID METHOD FOR DETERMINING THE CONTENT OF CALCIUM CARBONATE AND MAGNESIUM FLUORIDE IN SELLAITE AND FLUORITE-SELLAITE PRODUCTS

Claims

1. A rapid method for determining the content of calcium carbonate and magnesium fluoride in sellaite and fluorite-sellaite products, including treating a sample of the products with acetic acid, heating, adding a mixture of hydrochloric and boric acids, boiling, cooling the hot solution to room temperature, taking an aliquot, diluting with distilled water, adding a solution of triethanolamine, an indicator mixture, potassium hydroxide and titrating with a 0.025 M solution of Trilon B until the dark green color changes to violet, followed by determining the content of magnesium fluoride using the formula, %: where V is the volume of 0.025 M Trilon B solution used for titration of the reference sample, cm 3 ; V1 - volume of the entire analyzed solution, cm 3 ; V2 - volume of an aliquot of the analyzed solution, cm 3 ; m is the mass of the reference sample, g; K is a correction for the solubility of magnesium fluoride in acetic acid, equal to 0.1%; T is the titer of a 0.025 M solution of Trilon B, calculated using magnesium fluoride, g / cm 3 , in this case, the titer of the Trilon B solution is determined using a standard sample of sellaite concentrate and is calculated using the formula where C is the certified content of magnesium fluoride, %; K is a correction for the solubility of magnesium fluoride in acetic acid, equal to 0.1%; m is the mass of the reference sample, g; V1 - volume of the entire test solution, cm 3 ; V2 - volume of an aliquot of the test solution, cm 3 ; V is the volume of Trilon B solution used for titration, cm 3 , characterized in that the calcium carbonate content in sellaite and fluorite-sellaite products is first determined; for this purpose, after adding acetic acid to the product, boiling is carried out at a temperature of 210-220°C for 2-4 minutes, after which distilled water, potassium hydroxide, a triethanolamine solution and an indicator mixture consisting of fluorexone, thymolphthalein and potassium chloride are added to it, mixed until a dark green solution is obtained, which is then titrated with a 0.025M solution of Trilon B until the solution turns violet, after which the calcium carbonate content is determined using the formula where V is the volume of 0.025 M Trilon B solution used for titration of the reference sample, cm 3 ; m is the mass of the reference sample, g; K is a correction for the solubility of magnesium fluoride in acetic acid, equal to 0.1%; T is the titer of a 0.025 M solution of Trilon B, calculated based on calcium carbonate using the formula where C is the certified value of magnesium fluoride in the reference sample, %; K is a correction for the solubility of magnesium fluoride, equal to 0.13; m is the mass of the reference sample, g; V is the volume of 0.025 M Trilon B solution used for titration of the reference sample, cm 3 ; V1 - the volume of the total solution used; V2 - volume of an aliquot of the analyzed solution, cm 3 .

2. The express method according to paragraph 1, characterized in that when determining magnesium fluoride, concentrated hydrochloric acid is added to the solution.