I. Sodium Sulfide Dryer--Overview of Equipment

At present, the industrial sodium sulfide produced in China has red flake sodium sulfide, yellow flake sodium sulfide, red flake sodium sulfide iron content of about 300ppm, yellow iron content of sodium sulfide of about 30ppm. For some special customers, the iron content is lower, requiring <10ppm; especially in copper ore dressing, sulphur dyes and leather industry. For example, the production of high-quality high-grade sulphur dyes, the production of soft, hand-feeling leather, and the improvement of the quality of leather products require that the iron content of sodium sulfide products be <10ppm.

Adding manganese metal powder and/or manganese-based alloy powder to the zinc sulfate solution at a temperature of 50 ° C and pH > 4.0, stirring the reaction, after the reaction is completed, filtering and separating, and then crystallization by evaporation to obtain high-purity zinc sulfate, which will The prepared high-purity zinc sulfate is added with 5-10 kg of zinc sulfate per cubic centimeter of zinc sulfate, and 1 cubic cubic of zinc sulfate solution is prepared for each cubic filtrate; 150 kg of barium sulfide is added per cubic water, and the clear liquid is used; Two kinds of prepared solutions are added to the sodium sulfide filtrate at the same time, stirred, stirring speed 80 rpm, the reaction temperature is controlled above 80 ° C, and then precipitated for 12-16 hours, after removal of impurities, sent to the evaporation process, concentrated by evaporation That is, high purity sodium sulfide is obtained.

The method comprises the following steps: S600: taking a certain amount of crystalline sodium sulfide raw material into a vacuum kneading dryer, sealing the dryer, turning on the vacuum pump, and turning on the Roots blower. After the vacuum gauge is stabilized, the circulating oil pump is turned on, and the circulating oil is started to be heated. Control the temperature of the circulating oil, and stir the mixer evenly. After the equipment is running for a certain period of time, stop the stirring, close the upper valve of the dryer, introduce nitrogen into the dryer, open the feeding port, quickly take the material, and measure with a thermogravimetric analyzer. The remaining water content. After the dehydration reaction is completed, the vacuum pump and the Roots blower are turned off, the stirring is stopped, and the temperature is discharged; wherein the vacuum degree must be ≥0.096 MPa, and the temperature is dried by two stages, and the temperature is heated at a low temperature of 85 ° C for 1 hour; The section was heated at 115 ° C for 0.5 h; the material was cooled to below 40 ° C to discharge.