摘要
纳米级碳酸钙属于轻质碳酸钙,其平均粒径≤100nm。国内外已实现工业化有4种技术:间歇鼓泡式、连续喷雾式、间歇搅拌式和超重力式等。进行小试或中试有喷射式、喷杯式、超声空化式、高剪切式、内循环式、管道式、管线乳化式、列管式和复合式等9种碳化工艺。其共同特点为低温低浓下生产纳米碳酸钙,能耗高,设备投资大,生产能力低等。河北科技大学在总结现有生产工艺的基础上,提出高温高浓非冷冻式碳化工艺,经小试、70吨/年中试、2.5万吨/年工业装置工业化试验,在自行开发的多组分结晶导向剂的作用下,高温(35～75℃)高浓(7%～12%)工艺条件下,合成粒径分布均匀、平均直径为10～20nm、长径比为15～20、比表面积≥90m^2/g、总孔容≥0.26mL/g的针状(晶须)纳米碳酸钙。为工业化生产纳米级碳酸钙又开辟出一条新路子,其产品及综合技术处于国际领先水平。
Nano-sized Calcium Carbonate belongs to Light Calcium Carbonate, and the average diameter is less of 100nm, The four methods in world have realized industrialization： intermissive bubble method, stir reactor method, continual spraying technique and high-gravity technique, The nine methods have been laboratory experiment, High energy consumption of these methods impedes the application in commercial processes, Refrigerator was not used in the experiments for cooling the reactor to maintain low reaction temperature, which is usually used in the present nano-CaCQ production. Needle-like nanometer CaCQ was produced in a commercial reactor by using self-developed crystal-directing-agents under the conditions of the carbonization temperature as high as 30 - 75℃and Ca（OH）2 slurry concentration as high as 7% - 12%, The average diameter of the produced nano-CaCQ was 20nm, the aspect ratio 10 - 15,the specific surface area 〉 90m^2/g, This good technique is suitable for industrial production of Nano-sized Calcium Carbonate, Its product and technology keep ahead in the world.
关键词
纳米级碳酸钙
生产技术
高温高浓
非冷冻
新进展
nano-calcium carbonate
production technology
high temperature and concentration
no cooling
progress
