Method for producing potash magnesium sulphate fertilizer

Abstract

The invention discloses a method for producing potash magnesium sulphate fertilizer, comprising the following steps: a, crushing and grinding natural potash feldspar used as a raw material, screening the crushed raw material with a sieve of 150 meshes; b, adding proper amount of salt lake high-temperature salt of salt lake kalium extracting waste taking bischofite as a main component, baking for 2 to 3 hours at middle temperature under HCl protective atmosphere or sealed condition; c, after water quenching and solution leaching, adding salt lake kalium extracting waste epsomite into the solution obtained by filtrating, and evaporating the solution to concentrate and crystallize so as to obtain potash magnesium sulphate fertilizer. Compared with the prior art, the invention has advantages of taking magnesium salt lake kalium extracting waste as additive, having low baking temperature and simple separation process, recycling potassium chloride, potassium sulfate, picromerite and kainite left in the salt lake waste, being more feasible in economics, so that the potash magnesium sulphate fertilizer prepared by the method provides a plurality of nutrient elements for crops.

Description

technical field [0001] The invention relates to a production method of chemical fertilizers, in particular to a production method of potassium magnesium sulfate fertilizer. Background technique [0002] Potassium magnesium sulfate fertilizer (K 2 SO 4 · MgSO 4 ·6H 2 O) is an inorganic neutral fertilizer containing three nutrients K, Mg, and S. It has good water solubility and a relatively low salt index. Long-term application will not affect the pH value of the soil and has little impact on soil salinity. It is especially suitable For crops avoiding chlorine, it can significantly increase the yield and quality of commercial crops. [0003] At present, the exploitation and utilization of soluble potassium resources in salt lakes in my country cannot meet the needs of the planting industry, and about 75% of potassium fertilizers rely on imports. However, my country has relatively rich reserves of insoluble potassium resources represented by potassium feldspar. Therefore, p...

AI Technical Summary

Problems solved by technology

The utilization value of bischofite and Epsom salt is not high, and the transportation cost from the salt lake in Northwest China is very high. The magnesium salt of the salt lake in my country is hardly recycled, a large amount of magnesium salt in the salt lake is stockpiled, and more magnesium-containing waste liquid Usually discharged, for example, 12 to 18 million tons of magnesium chloride-containing waste liquid was discharged from Qinghai Chaerhan Salt Lake, and the discharged magnesium-containing waste liquid often leaked underground, seriously affecting the composition of intercrystalline brine and the exploitation and utilization of salt lake resources, resulting in the so-called " Magnesium damage", thus restricting the normal and continuous production of potash fertilizer in salt lakes and destroying the ecosystem and environment of salt lakes

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