METHOD FOR PROCESSING QUARTZ-LEUCOXENE CONCENTRATE Russian patent published in 2022 - IPC C22B34/12 C22B3/06 C01G23/53 

FIELD: material processing.

SUBSTANCE: invention relates to methods for processing quartz-leucoxene concentrate and can be used to produce artificial rutile. The method involves mixing the initial concentrate with a 10-40% solution of ammonium hydrodifluoride at a mass ratio of concentrate to ammonium hydrodifluoride solution as 1: (5-20) at a temperature of 75 to 90°C for 1-4 hours, while capturing ammonia with water to obtain an aqueous solution of ammonia. The solid precipitate filtered from the obtained pulp is dried at a temperature of 60-80°C for 2-6 hours, and then it is fired at 600-900°C for 1-4 hours, obtaining artificial rutile. In this case, the exhaust gases are captured with water and combined with an ammonium fluoride solution after subsequent filtration of a suspension of silicon dioxide. The filtrate is treated with an aqueous solution of ammonia. The resulting suspension of hydrated silicon dioxide is filtered, and the precipitate is calcined at a temperature of 500-800°C for 2-6 hours, obtaining silicon dioxide in the form of a product, while the exhaust gases are captured with water to obtain ammonium hydrodifluoride, which is combined with a solution of ammonium fluoride after filtration of the suspension of hydrated silicon dioxide and with a solution obtained after capturing gases during drying and firing of the pulp sediment. The combined solutions of ammonium fluorides are evaporated at a temperature of 130-170°C, obtaining crystalline ammonium hydrodifluoride for fluoridation of a new portion of the initial concentrate.

EFFECT: waste-free processing of quartz-leucoxene concentrate is provided to produce marketable products: silicon dioxide and artificial rutile.

1 cl, 3 ex