低成本纳米碳酸钙的合成与改性

Synthesis and modification of low-cost nano-sized calcium carbonate

以重庆皇华碳酸钙有限公司钢窑生产的石灰经消化、精制后的氢氧化钙悬浊液和二氧化碳体积分数为33%-35%的窑气作为实验原料,运用非冷冻搅拌鼓泡碳化法,通过自主研发的特殊搅拌器和气体分布器,添加一定量的助剂合成了纳米碳酸钙。实验中发现自主研发的特殊搅拌器和气体分布器能很好地解决气体分散和混合问题。研究结果表明：通过控制搅拌线速度、窑气流量等条件,可以在一定范围内实现不同粒径的纳米碳酸钙的制备。在此基础上,运用湿法改性,通过自主研发的特殊搅拌器,添加一定量的改性剂,并采用变频控制,很好地实现了低成本、高品位的改性纳米碳酸钙的生产。

Nano sized calcium carbonate was synthesized by non-frozen gas blow mixing carbonation method. This experiment used calcium hydroxide suspension, which was produced by digesting and refining the lime produced in steel kiln of Chongqing Huanghua Calcium Carbonate Co. , and the kiln gas with volume fraction of carbon dioxide of 33% -35% as raw materials. This experiment also adopted self〈leveloped sepeial blender and gas distributor and a certain amount of accessory ingredient in synthesis process. During the experiment, it was found that the problems of gas dispersion and mixing were solved well by self-developed blender and distributor. Research results showed that the preparation of nano-sized calcium carbonate with different particle sizes could be achieved within a certain range by controlling linear velocity of stirring and kiln gas flow. On this basis, the use of wet modification, through special self-developed blender, adding a certain amount of modifier and using variable frequency control, the production of low-cost, high-grade nano-sized modified calcium carbonate could be achieved.