卤水-氨法反向沉淀对氢氧化镁结晶生长的影响  

Effect of brine-ammonia reverse precipitation on crystal growth of magnesium hydroxide

作　　者：刘辉 罗才贵[1] 邹来禧 宋学文[2] 柳殷 罗仙平[1,2] LIU Hui;LUO Caigui;ZOU Laixi;SONG Xuewen;LIU Yin;LUO Xianping(School of Resources and Environmental Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China;Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]江西理工大学资源与环境工程学院,江西赣州341000 [2]西安建筑科技大学,西安710055

出　　处：《有色金属科学与工程》2023年第2期151-160,共10页Nonferrous Metals Science and Engineering

基　　金：国家重点研发计划资助项目(2018YFC1903805);青海省重大科技专项资助项目(2020-GX-A1)。

摘　　要：以盐湖卤水和氨水为原料,采用反向沉淀法合成六角片状氢氧化镁。研究了Mg^(2+)离子浓度、反应温度、进料速度、陈化时间等反应条件对氢氧化镁结晶度、粒径和氯根含量的影响,综合反映氢氧化镁晶面生长情况。通过SEM、XRD、激光粒度分析仪进行了表征分析。结果表明,Mg^(2+)离子浓度和反应温度的提高,有利于氢氧化镁(001)晶面的生长。随着Mg^(2+)离子浓度的增大、陈化时间的延长,氢氧化镁中的氯根含量增大。氢氧化镁的粒径受反应条件及晶面生长、极性影响较大。通过盐湖卤水-氨法反向沉淀能够制备(001)晶面尺寸为13.1~19.4 nm、粒径D_(50)为1.64~9.32μm,Cl^(-)-含量<0.1%的六角片状氢氧化镁。可望为调控盐湖水氯镁石制备氢氧化镁晶面生长提供科学依据,并为利用盐湖资源制备高纯、高附加值的氢氧化镁功能材料提供借鉴。Reverse precipitation method was applied to synthesize hexagonal flaky magnesium hydroxide by using brine of salt lake and ammonia as raw materials.The effects of magnesium ion concentration,reaction temperature,feed rate and aging time on the crystallinity,particle size and chloride content of magnesium hydroxide were studied,and the crystal plane growth of magnesium hydroxide was comprehensively reflected.Herein,characterization analysis of the samples was carried out by SEM,XRD and laser particle size analyzer.The results showed that,with the increase of Mg^(2+)ion concentration and reaction temperature,it was favorable for the crystal plane growth of magnesium hydroxide(001).The increase of Mg^(2+)ion concentration and the prolongation of aging time made the chloride content of magnesium hydroxide increase.Its particle size was greatly affected by reaction conditions,crystal plane growth and polarity.Hexagonal flaky magnesium hydroxide with(001)crystal face size of 13.1-19.4 nm,particle size D_(50) of 1.64-9.32μm,and chloride content<0.1%could be prepared by brine-ammonia reverse precipitation.These results could not only provide a scientific basis for regulating the growth of magnesium hydroxide crystal planes prepared from bischofite in salt lakes,but also offer a useful reference for using salt lake resources to prepare high-purity,high-value-added functional materials of magnesium hydroxide.

关 键 词：盐湖卤水 氨法反向沉淀 氢氧化镁 结晶生长 

分 类 号：TF111.34[冶金工程—冶金物理化学]