Lanhua Huaming Innovates Nanometer Calcium Carbonate Process    

After the use of the concentrated carbon dioxide carbonization and atmospheric-temperature packing/coating technology developed by Shanxi Lanhua Huaming Nanometer Material Co., Ltd. (Lanhua Huaming) in its 15 000 t/a nanometer-grade calcium carbonate unit, not only the capacity and the product quality are greatly improved, the comprehensive energy consumption of the unit also fall significantly.
    Carbonization and packing/coating are two key steps in the production of nanometer-grade calcium carbonate. Local producers mostly use carbon dioxide with medium concentration generated in coal combustion as carbonizing agent, in which the carbonization efficiency is low, more coal are consumed and great quantities of smog are discharged to air. Lanhua Huaming uses carbon dioxide with a purity of over 95% generated from nearby chemical fertilizer plants into the carbonization tower as carbonizing agent. The consumption of coal per ton of nanometer-grade calcium carbonate is reduced to 0.3 tons from 0.6 tons in continental process. As carbon dioxide the company used has a high purity, so the reaction speed is quickened and the power consumption is reduced. Hence the reaction time per batch of products is down to one hour from ten hours in continental process and the power consumption per ton of product is down from 650 kWh to 251 kWh.
    High-temperature packing/coating is the technology popular in the production of nanometer calcium carbonate at present in China. It needs a long reaction time, great power consumption and low production efficiency. Lanhua Huaming has developed a new surface activator that makes the atmospheric-temperature packing/coating possible. The heating step is removed and the product quality and the production efficiency are upgraded. The power consumption is therefore reduced by 150 kWh per hour.