Study On Mechanism And New Process Of Potassium Extraction From Potash Feldspar

This paper has summarized the research conditions of potash feldspar at China and abroad. The physical and chemical properties of potash feldspar of Anhui Ningguo have been characterized by XRD , TG-DTA etc. The extraction of potassium from potash feldspar with four additives NaCl, CaCl₂, SrCl₂ and BaCl₂ has been studied. The calcinations temperature and the dose of additives that effect the extraction of potassium were discussed, and great changes have been taken place on the efficiency of potassium extraction at near the melting points of additives. The phase compositions of potash feldspar and it's calcined, and water insoluble substances of co-calcining of potash feldspar with additives were analyzed by XRD. The experiment results shown that the aluminsiloxane network structures were not damaged after calcining, and the mechanism of potassium extraction by co-calcining was ion -exchange. It was shown that the order of exchange capabilities of potassium extraction of additives was Na⁺ >Ca²⁺>Sr²⁺>Ba²⁺, which were consistent with that of theoretical predication. Furthermore, as the calcining temperature is over the melting points of NaCl or CaCl₂, it was also shown that both of additives were much better than others and the potassium ion - exchange degrees were more than 90%.With the ion-exchange theory, a very gender reaction condition of new process has been researched. The effects of the dose of additives, reaction temperature and ratios of reactants on the potassium ion -exchange degrees were researched and the optimum technological parameters were determined by means of quadrature experiment. At last the optimum operation conditions were confirmed as follow, 250℃, additives:2.23ml, m(additives):m(potash feldspar)=l:l. The phase compositions of water insoluble substances of products were analyzed by XRD and the reaction mechanism of the new process was also belong ion-exchange. Test results show a recovery of up to 92%.