Slow‐release dissolution characteristics of Li ⁺ , K ⁺ , and Rb ⁺ in silicon potassium fertilizer based on surface properties

Coal gangue is one of the largest accumulated industrial solid wastes in China, rich in minerals such as silicon, rubidium, and cesium. A silicon potassium fertilizer with slow‐release and water‐retention properties is prepared using coal gangue and potassium‐containing minerals. The two raw materials are mixed in proportion and calcined at high temperatures to obtain silicon potassium fertilizer. Experimental and computer simulation methods are employed to investigate the slow‐release performance of Li + , Rb + , K + , and Si 4+ in the fertilizer, as well as the charge transfer patterns of rubidium and lithium at the solid–liquid interface. A “two‐step” process that fully utilizes the dispersed high‐value trace elements in the silicon potassium fertilizer is established. It has changed the current situation of the one‐step or extensive utilization of coal gangue. providing new ideas for the comprehensive utilization of solid waste and the utilization of high‐value trace elements.