METHOD OF OBTAINING SODIUM HYDROXIDE FROM LIQUID WASTES OF FIBROUS MASS PRODUCTION Russian patent published in 2015 - IPC C01D1/04 D21C11/12 

FIELD: chemistry.

SUBSTANCE: claimed is method of obtaining sodium hydroxide from liquid wastes of fibrous mass production, where flow of said wastes contains organic wastes and sodium bound with them. In accordance with said method liquid wastes are concentrated and burnt on oxidative medium with decomposition of organic wastes and sodium compounds. Before burning, borate or borate-forming compound is introduced into liquid wastes. After that, sodium compounds are subjected to autocaustification reaction, with borate-containing organic wastes being subjected to two-stage processing by burning, where at first stage burning takes place in oxidative medium and at temperature above 1000°C, after which flue gases, formed in the process of burning, are quickly cooled to temperature below 600°C providing sublimation of sodium compounds from their gaseous phase directly into solid phase. Residual products of burning contain ash, formed in the process of burning liquid wastes, which is removed and dissolved or suspended in water with obtaining sodium hydroxide in water phase.

EFFECT: invention provides novel solution for extraction of alkali in the process of production of fibrous mass, as well as extends areas of application of alkaline chemical reagents, extracted by means of Alrec process.

21 cl, 1 tbl, 1 ex, 1 dwg