Effect of manganese salts on recovery of potassium from K-feldspar by means of a calcination reaction in the chloride salts-calcium carbonate system

ABSTRACT

Potassium feldspar is a typical insoluble potassium ore with enormous deposits in China. Its industrial utilization has not been developed yet because of high costs and technological difficulties. One of the problems is related to a low potassium extraction ratio. To address this, the KAS₆-chloride salts-CaCO₃ system has been studied with a focus on the influence of calcination temperature, type, and the portion of additives. The results demonstrate that the extraction ratio of potassium appeared to be typically extremely low because of the nature of CaCO₃ additive. The extraction ratio can be notably raised by increasing the content of chloride salts. The potassium extraction has been shown to reach 85% in the KAS₆-MgCl₂-CaCO₃ and KAS₆-CaCl₂-CaCO₃ systems, whereas the leaching rate was only 60% in the KAS₆-NaCl-CaCO₃ system at 800°C. Extraction in the KAS₆-NaCl-CaCO₃ system increased as the roasting temperature raised to 900°C. With the mass ratio of KAS₆:NaCl:CaCO₃ = 1:2:4, the extraction of potassium constitutes to 97.29% at 900°C. A method of improving the extraction of potassium in the KAS₆-chloride salts-CaCO₃ system with manganese ions as an additive has been investigated. The results indicate that adding 5 wt% anhydrous manganese sulfates enables to increase the leaching rate of potassium in the KAS₆-chloride salts-CaCO₃ system.

KEYWORDS:

• K-feldspar
• roasting
• potassium extraction
• mineral processing

Acknowledgments

The authors wish to acknowledge the Guizhou Provincial Science and Technology Foundation (Grant (2018)1421) and the Fundamental Research Funds for the Central Universities (Grant 22A201514058) for financial support.

Additional information

Funding

Project ((2018)1421) supported by the Guizhou Provincial Science and Technology Foundation, Project (22A201514058) supported by Fundamental Research Funds for the Central Universities.

Notes on contributors

Yu-Ling Shi

Yu-Ling Shi, Research Center for Integrated Utilization of Salt Lake Resource, East China University of Science and Technology, Shanghai 200237, ChinaShe is bachelor candidate in chemical engineering at the School of Resources and Environmental Engineering, ECUST. Her research interests include extraction technology for potassium-containing minerals.

You-Fa Jiang

You-Fa Jiang holds bachelor degree in applied chemistry in Jilin Institute of Chemical Technology. He is Ph.D. candidate in chemical engineering at the School of Resources and Environmental Engineering, ECUST. His research interests include extraction technology for minerals leaching, crystallization separation for potassium or aluminum.

Cheng-Lin Liu

Cheng-Lin Liu holds a Ph.D. in chemical engineering in East China University of Science and Technology (ECUST), Shanghai, P. R. China and bachelor degree in chemical engineering and technology at Chongqing University. He serves as a master mentor at the School of Resources and Environmental Engineering, ECUST. His research interests include multiphysics-coupled numerical analysis in the multiphase reactor, industrial solid waste, extraction technology for lithium or potassium-containing minerals and CO₂ mineralization.

Jian-Guo Yu

Jian-Guo Yu holds a Ph.D. in chemical engineering in East China University of Science and Technology (ECUST), Shanghai, P. R. China. He serves as a professor at the School of Resources and Environmental Engineering, ECUST, since 1998. He has published more than 300 research articles and 70 invention patents to his credit and supervises dozens of MS and Ph.D. students. He is the leader of National Engineering Research Center for Integrated Utilization of Salt Lake Resource and a member of several professional societies. His research interests include integrated utilization of salt lake resource and solid waste.