Inorganic Chemicals Industry ›› 2022, Vol. 54 ›› Issue (5): 72-78.doi: 10.19964/j.issn.1006-4990.2021-0465

• Research & Development • Previous Articles     Next Articles

Study on yield of KCl prepared by cold crystallization of low?sodium carnallite

QIE Zhijia(),DONG Weibing,DU Jingling,MA Shengkui,WANG Gang()   

  1. Key Laboratory of Resource Chemistry and Eco?environmental Protection in Tibetan Plateau,Qinghai Nationalities University,Xining 810007,China
  • Received:2021-08-03 Online:2022-05-10 Published:2022-05-31
  • Contact: WANG Gang E-mail:1723009589@qq.com;wanggang5208@163.com

Abstract:

The process of preparing potassium chloride by reverse flotation?cold crystallization method mainly includes three operating processes of flotation,crystallization and washing.Among them,the yield of potassium chloride in crystallization process is relatively low.The effect of the mass ratio of decomposition liquid to low?sodium carnallite,concentration of magnesium decomposition liquid,raw ore impurity ions and crystallization temperature on the yield of potassium chloride was studied experimentally.The research results showed that when the mass ratio was 1∶1.2,the yield was more than 63% and the quality of KCl could reach 95.06%.Increasing the concentration of magnesium decomposition liquid was beneficial to the crystallization yield of potassium chloride.When the concentration was 2.5 mol/L,the yield could reach more than 74%.The concentration range of this experiment was 0.05~0.15 mol/L,SO42- was beneficial for enhancing the yield of KCl.When the Ca2+ doping concentration was greater than 0.1 mol/L,the crystallization of potassium chloride was inhibited and the yield was decreased by 2.99%.When the Na+ doping concentration was increased to 0.3 mol/L,the yield decreased from 63.66% to 52.53%.With the increase of crystallization temperature,the yield of potassium chloride was decreased significantly.When the temperature was 15 ℃,the yield reached 76.55%,and when the temperature was increased to 25 ℃,the yield was decreased to 63.39%.

Key words: potassium chloride, Low-sodium carnallite, reverse flotation-cold crystallization, yield

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