综合利用白云石开发出高端产品及其技术成为当前研究者关注的焦点.本文通过可控碳化法进行白云石联产制备了高附加值的氢氧化镁和碳酸钙并对其进行改性研究.分别考察了碳化终点pH、温度、二氧化碳流速对产物晶型、粒径、形貌的影响以及硬脂酸锌的添加量、搅拌转速、改性时间、改性温度对产物改性效果的影响.结果表明,当碳化反应终点pH控制为10.5时,生成产物为碳酸钙和氢氧化镁混合物,且得率最高;最优的碳化反应条件为温度20℃、二氧化碳流速1L/min,生成的氢氧化镁和碳酸钙平均粒径为190.4nm;得到的产物氢氧化镁和碳酸钙最优的改性条件为硬脂酸锌添加量1.0％、搅拌转速600r/min、改性时间60min、改性温度50℃,得到改性的氢氧化镁及碳酸钙的活化度为95.8％,吸油值为41.2g/100g.
The comprehensive use of dolomite for the development of high-end products and their technologies have become the focus of current researchers.In this paper,high value-added magnesium hydroxide and calcium carbonate were prepared by controlled carbonation method of dolomite and modified.The effects of pH at the end-point,temperature and CO2 flow rate of carbonation on the crystalline and particle morphology of the products,as well as the effects of zinc stearate addition,stirring speed,time and temperature on the modification of the products were investigated respectively.The results showed that when the pH at the end-point of carbonation reaction was controlled to 10.5,the products contained only calcium carbonate and magnesium hydroxide;the optimal carbonation reaction conditions were 20℃ and CO2 flow rate 1L/min,and the average particle size of magnesium hydroxide and calcium carbonate was 190.4nm;the optimal modification conditions of magnesium hydroxide and calcium carbonate were zinc stearate addition 1.0％,stirring speed 600r/min,modification time 60min,and modification temperature 50℃,the activation degree of the modified magnesium hydroxide and calcium carbonate was 95.8％,and the oil absorption value was 41.2g/100g.
彭李佳;王银龙;翟宸;王琦;陈小鹏;童张法
广西大学化学化工学院,广西南宁 530004||广西碳酸钙产业化工程院有限公司,广西南宁 530004广西大学化学化工学院,广西南宁 530004
化学工程
白云石;氢氧化镁;碳酸钙;硬脂酸锌;改性;可控碳化
dolomite;magnesium hydroxide;calcium carbonate;zinc stearate;modification;controlled-carbonation
《化工进展》 2024 (004)
1981-1991 / 11
国家自然科学基金(52162004);南宁市科学研究与技术开发计划(20211011).
10.16085/j.issn.1000-6613.2023-0688
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