Method for preparing potassium chloride from carnallite

US11851340B2 · kind B2 · utility

Assignee

• QINGHAI INSTITUTE OF SALT LAKES, CHINESE ACADEMY OF SCIENCES · CN

Inventors

• Min Wang · Gilbert, US
• Lijie Shi · Solo Court, CN

Key dates

• Filing date: Apr 30, 2021
• Grant date: Dec 26, 2023
• Expiry date: Apr 30, 2041

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02A40/20
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A method for preparing potassium chloride from carnallite includes: carrying out high-temperature water solution mining treatment on carnallite with fresh water to obtain potassium-rich saturated brine; mixing the potassium-rich saturated brine, a sylvine saturated solution, and bittern for mixing brine, evaporation and decomposition to obtain artificial sylvine; and carrying out low-temperature selective dissolution treatment on the artificial sylvine with fresh water to prepare potassium chloride. The carnallite is mined by using hot water, which reduces the content of sodium chloride in the potassium-rich saturated brine; artificial sylvine is only subjected to low-temperature selective dissolution once, which avoids unnecessary energy consumption and impurity accumulation unnecessary for multifold cycles of thermal dissolution-cold crystallization treatment of sylvine while guaranteeing the high yield and high quality of potassium chloride. The method is suitable for different grades of carnallite, has extremely strong adaptability and loose technical conditions, and is conducive to promotion and implementation.