以卤水和氟硼酸钠为原料,反应制备出氟硼酸钾固体,再以浓硫酸和氟硼酸钾反应,制备出硫酸钾.在制备氟硼酸钾步骤中,以氟硼酸钠添加量、反应温度、反应时间为变量;在氟硼酸钾与浓硫酸反应步骤中,以浓硫酸添加量、反应温度、反应时间为变量,通过单因素变量法探索出该工艺海水提钾并制备硫酸钾的最佳条件,即提钾过程中BF4-与K+摩尔比为1.13:1,反应温度10℃,时间30 min,此条件下钾离子回收率可达92.8%,通过XRD检测可知,沉淀成分为氟硼酸钾.制备硫酸钾过程中,浓硫酸与KBF4摩尔比为0.697:1,反应温度600℃,时间90 min.该工艺钾提取率较高,所用试剂氟硼酸钠能回收再利用,为我国卤水提钾以解决钾资源缺乏问题开辟了新的思路.%Brine water and sodium fluoroborate were adopted as raw material to prepare potassium fluoroborate, then potassium sulfate was achieved after reacting concentrate sulfate acid and potassium fluoroborate. In the process of preparing potassium fluoroborate, addition of sodium fluoroborate, reaction temperature, and reaction time were studied, then in the process of preparing potassium sulfate, sulfate acid addition, reaction temperature, and reaction time were studied, through single factor experiment, the optimum conditions of extract potassium from sea brine to prepare potassium sulfate was obtained, namely, mole ratio of BF4- to K+ was 1.13:1, reaction temperature was 10 ℃, reaction time was 30 min, and the recovery rate of potassium can reach 92.8%, then dry the sediment, and prepare potassium sulfate with concentrate sulfate acid at the condition of mole ratio of sulfate to potassium fluoroborate 0.697:1, temperature of 600 oC, time of 90 min. Through XRD analysis, it can be concluded the sediment to be potassium fluoroborate. The process is the first to put forward preparing potassium sulfate from brine water with sodium fluoroborate with relatively high potassium recovery and recyclable sodium fluoroborate. This process may open up a new train to extract potassium from sea brine water to solve the problem of lack of potassium resource in China.
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