Process of preparing magnesium potassium sulfate fertilizer with bittern containing potassium and magnesium sulfite

Abstract

The process of preparing magnesium potassium sulfate fertilizer with bittern containing potassium and magnesium sulfate includes the following steps: 1. spreading and shinning the bittern to form mixed potassium salt; 2. collecting mixed potassium salt slurry with pump; 3. regulating the concentration of the slurry to not higher than 20 %; 4. mixing the slurry and floating chemical to float; 5. adding fresh water or slight salty water in the amount one 0.3-0.6 times the floated mixed potassium salt to convert the slurry; 6. solid-liquid separating to obtain soft wet potassium and magnesium alum; 7. washing with fresh water or slight salty water and solid-liquid separating to obtain soft wet potassium and magnesium alum; and 8. drying to obtain magnesium potassium sulfate fertilizer. The process of the present invention is simple, has high quality of the produced magnesium potassium sulfate fertilizer, and is designed specially for water process collected bittern material.

Description

technical field [0001] The invention relates to a method for preparing potassium-magnesium sulfate fertilizer, in particular to a method for preparing potassium-magnesium sulfate fertilizer by using potassium-containing magnesium sulfate subtype brine. Background technique [0002] The molecular formula of potassium magnesium sulfate fertilizer is K 2 SO 4 · Mg 2 SO 4 ·6H 2 O, whose scientific name is kaleinite, is a new type of agricultural fertilizer. [0003] The inventor of the patent application of the present invention thinks that the Chinese invention patent application with the application number 02143641.X and the name "Method for Producing Potassium Sulphate from Potassium-containing Magnesium Sulfate Subtype Brine" is the closest existing patent application of the present invention Technology, in this prior art, jalebisite is its intermediate product; There is following problem in this prior art and the part that the present invention repeats: [0004] 1. Th...

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Problems solved by technology

[0004] 1. The salt field process is complex; the salt field process of the prior art comprises five mutually independent salt-out processes in total, i.e. sodium chloride section, epsom salt section, potassium halite section, carnallite section and old brine section. A total of five independent salt pans for different salt precipitation processes need to be set up, so the salt pan process is complicated

[0005] 2. gained potassium magnesium sulfate fertilizer, i.e. the quality of langbeinite is poor; Because the langbeinite in this prior art is an intermediate product, so the langbeinite in this prior art has the high content of chloride radicals and For the problem of low potassium ion content, the weight percentage of the chloride content is about 2 to 3%, and the weight percentage of the potassium ion content is about 12 to 18%.

[0006] 3. This prior art is not specially designed for mining by water mining method; there are two methods of extracting the potassium mixed salt crystallized out in the salt pan during the potassium mixed salt stage: dry mining method and water mining method;

[0009] The mining cost of potassium mixed salt by dry mining method is more than 8 yuan / ton, while the mining cost of potassium mixed salt by water mining method is only about 5 yuan / ton; because the operating cost of water mining method is much lower than that of dry mining method, Therefore, the water mining method is very suitable for long-term mining in large mines; but this prior art is not aimed at the characteristics of the potassium mixed salt slurry composed of potassium mixed salt and potassium mixed salt stage salt field brine that is produced by the water mining method Design the subsequent processing technology

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