| 摘要 |
<p>In the present invention there is disclosed a regeneration process of chemicals from wash water and extracts by making use of thermal oxidation. The invented process is characterized in that from a mixture of separated extracts and wash water with temperature ranging from 30 to 90 degC and calcium oxide or hydroxide there is formed by mixing a suspension. After dosage of oxygen under high pressure and heating the mixture to a temperature up to at least 300 degC the mixture is subjected for a period of 5 to 15 minutes to thermal oxidation. Subsequently, after cooling down to temperature ranging from 30 to 80 degC and further addition of calcium oxide or hydroxide, the mixture is subjected after mixing thereof to caustification under formation of sodium hydroxide and precipitate of calcium carbonate, optionally with a portion of calcium sulfate. Filtration or sedimentation then separates the precipitated suspension and the regenerated sodium hydroxide filtrate is collected for further use. The apparatus for making the above described regeneration process of chemicals is formed by a tank (1) of extracts, that is connected with a mixing tank (3) being connected with a main storage tank (2) of calcium oxide and being further connected via a high-pressure pump (4) and a primary circuit of a countercurrent heat-exchange apparatus (5) with a pressure reactor (6). The pressure reactor (6) is connected via a secondary circuit of the heat-exchange apparatus (5) with a caustification tank (8) that is parallel-connected with an auxiliary tank (7) of calcium oxide and that is further connected with a settling tank (9). The settling tank (9) is connected by a circulating circuit with a dewatering tank (11) and a storage tank (10), whereby in front of and/or beyond the high-pressure pump there is parallel-connected in the circuit an oxygen storage tank (12).</p> |
