Mineral potassium fertilizer and preparation method thereof

The invention provides a mineral potassium fertilizer and a preparation method thereof, and belongs to the technical field of fertilizers. By selecting the specific activating agent and the preparation process, the problems of complex preparation process, poor product quality and the like of the mineral potash fertilizer in the prior art are solved. The mineral potash fertilizer provided by the invention is wide in raw material source, relatively low in cost, simple in manufacturing process, free of emission of three wastes and suitable for industrial large-scale production; the effective potassium content of the prepared mineral potash fertilizer can reach 15-45%, the effective silicon content is greater than 20%, the effective magnesium content is greater than 10%, and the mineral potash fertilizer contains various trace elements. Due to the citric acid-soluble mineral potash fertilizer, nutrients can be slowly released according to plant requirements, and the fertilizer efficiency utilization rate almost r