Kinetics Of Low-grade Salt Lake Potash Dissolved In Solvents

Leaching mining of low-grade potash, there are two problems: a serious waste of resources and leaching channels are blocked. In order to make full and efficient use of resources, it is necessary to actively improve mining methods and process conditions Conducted leaching mining process conditions studied by single factor and orthogonal experiments to determine the optimum conditions are: solid-liquid ratio is 1: 0.5; solvent ratio is 50% sodium chloride saturation and the mass fraction of magnesium chloride is 3%; dissolution time is 72 h. Under these conditions, the content of KCl is greater than 1.2%, salt skeleton does not collapse, leaching channels unobstructed, meet the technical requirements.Based on the above experimental results, investigating the dissolution performance and rules of Mohair salt in different solvents, the dissolution tests were carried out. According to the our group’s previous orthogonal experiment, mass fraction of 13.24%(saturation of 50%) Na Cl solution and mass fraction of 13.24% + mass fraction of 3% Mg Cl2 solution were chosen as solvent for the dissolution tests, respectively, and the results were compared with the blank test which used pure water as solvent, and the dissolution kinetics of K+, Na+ of Mohair salt mine in different conditions were calculated. Date was described by ion c-t chart, and dissolve kinetics curves were made by nonlinear fitting. Two parameters, K and n, of the stumm model were calculated by Runge-Kutta differential equations and simplex method. All the calculation was realized by matlab program. According to the the dissolution kinetics, the dissolution rules of K+, Na+ in different conditions were found: After adding Na Cl, the dissolution rate of K+ increased while the dissolution rate of Na+ decreased; On the basis of the top, the dissolution rate of K+ increased much obviously, and the rate constant of K+ increased from 0.1126 to 0.8749, and the rate constant of Na+ remained around 10-10.