METHOD OF PRODUCING HIGH-PURITY BARIUM CARBONATE Russian patent published in 2011 - IPC C01F11/18 

FIELD: chemistry.

SUBSTANCE: invention relates to production of highly pure carbonates of alkali-earth metals used in optical glass manufacturing and fibre optics. To obtain barium carbonate, first, initial barium nitrate solution undergoes pre-treatment with aluminium nitrate in amount of 2% of the weight of anhydrous barium nitrate and with alkali to pH 8.0-8.3, followed by separation of the solution from the precipitate. Barium carbonate is then chemically deposited from the cleaned barium nitrate solution using carbon dioxide gas which is fed into the reactor simultaneously with the cleaned barium nitrate solution and a stream of ammonia gas or its aqueous solution. Chemical deposition is carried out using stoichiometric amounts of reagents, temperature of 42-45°C, pH 7.8-8.2 and while stirring the reaction mixture at 900-1000 rpm. The obtained product is separated via filtration, washed with clean water and dried at 115-125°C.

EFFECT: invention increases efficiency of the process of producing barium carbonate and purity of the obtained product.

2 cl, 4 ex