Research on Pre-Treatment Technology and Analysis Methods for Main Components in Soluble Potassium Salt

Potassium salt is one of the scarcest mineral resources in China, and it is the main raw material for potassium fertilizer in the three major fertilizers of agriculture. Currently, soluble potassium salt resources are the main ones with development and utilization value. At present, there is no national standard material or standard analysis method for soluble potassium salts. In the experiments, soluble potassium salt samples were dissolved by electric heating plate and ultrasonic oscillation. According to the main components of soluble potassium salts, a method for the determination of K⁺, Na⁺, Ca²⁺ and Mg²⁺ by ICP-OES and a method for the determination of Cl⁻ and SO₄ ²⁻ by ion chromatography (IC) in soluble potassium salts were established. Through experimental conditions, the dissolution temperature of the electric heating plate was determined to be 160℃ and slightly boiled for 20min; the ultrasonic oscillation dissolution power was 60Hz and the time was 20min. The precision of the two methods was between 0.55%−3.19% (RSD, n=11), and the detection limit was between 0.01μg/g to 0.05μg/g. Both dissolution methods of soluble potassium salts can be widely used in daily detection. The electric heating plate dissolution method is more suitable for batch sample analysis in the laboratory. The ultrasonic oscillator dissolution method is simple and fast, and can be widely used in the field exploration of potassium salts, which can greatly improve the work efficiency and guide the smooth development of prospecting operations in real time.