TH25180B - Process for pretreatment of fly ash - Google Patents

Abstract

DC60 (07/11/43) A process invention for the pretreatment of fly ash accumulated in an electro-filter of a soda recovery unit in a sulfate cellulose mill where most of the ash contains Na. Sulfates, Na Chloride, Na Carbonates and K Sulfates for the production of industrial raw materials, in which the dissolution of fly ash, the carbonates in it are dissociated. Out with hydrochloric acid to Na chloride, add chemical sulfate precipitate in chloride form, separate sulfate precipitate obtained from solution and take solution. Containing chloride back The invention of a process for the pretreatment of fly ash accumulated in an electro-filter of the soda recovery unit in a sulfate cellulose mill, where most of the ash contains Na sulfate, Na chloride. Rides, Na carbonates and K sulphates to produce industrial raw materials which, in the process of dissolving fly ash, the carbonates contained therein are decomposed. Out with hydrochloric acid until Na chloride, Tim chemical was taken into sulfate in chloride form, separated sulfate precipitate obtained from solution and taken solution. Containing chloride back

Claims (4)

1. Process for pretreatment of fly ash accumulated in the strainer of the soda recovery unit in a sulfate cellulose mill where most of the ash contains Na sulfate, Na chloride, Na carbone. And K sulfate to produce Industrial raw materials It consists of a process for dissolving fly ash in water, separation of the carbonate in it with hydrochloric acid to Na chloride, adding flocculant chemicals. Sulfate as chloride, the separation of the sulfate precipitate from the solution, and the recovery of the chloride-containing solution, in all this manner so that all chemicals from the production of the cellulose sulfate were deposited The fly ash is literally recoverable, whereby the chemical precipitation is calcium chloride, and after the separation of calcium sulphate precipitate, Motherliver is purified by the method. Of barium chloride to get rid of excessive sulfates. 2. Procedure according to claim 1 where, after separating the calcium sulphate sludge, further purification is added by means of sodium carbonate to remove excess calcium. 3. Clause according to claim 1 where the fraction of Na is separated by crystallization. Before adding calcium chloride 4. Clause according to claim 1 where the chloride solution recovered by that method was used As a raw material in electrolysis processes