Calcium hydroxide is a white powdery solid commonly known as hydrated lime, hydrated lime, and slightly soluble in water. Its aqueous solution is known as clarified lime water. Calcium hydroxide has a basic nature and is a strong base. The application of calcium hydroxide has developed rapidly and has been widely used in both production and life. Calcium hydroxide has become an irreplaceable material, and a large number of hydroxides have been used in metallurgy, pharmaceutical food, sugar and chemical industry, paper-making, petroleum additives, waste incineration flue gas treatment, sewage treatment, coal-fired power plant desulphurization, manufacturing of bleaching powder, etc. Calcium and calcium hydroxide can also be used as hard water softeners, disinfectants, antacids, astringents, and the like.
 
Some industry analysts pointed out that in recent years, the calcium hydroxide industry in China has been growing rapidly at a rate of around 15%. In 2011, the output of calcium hydroxide in China was approximately 5.98 million tons. In 2012, the production of calcium hydroxide in China was approximately 6.75 million tons, with a year-on-year increase of 12.9%. In 2013, the output of calcium hydroxide in China was approximately 7.68 million tons with a year-on-year increase of 13.8%.
 
Calcium hydroxide plays an important role in environmental protection treatment. Calcium hydroxide can be used as a strong alkaline agent to neutralize acidic waste-water or heavy metal waste-water, making acidic waste-water neutral, and superior to sodium hydroxide lye in the treatment of waste-water. It is the world's first choice of alkaline neutralizing agent; it can absorb so2 in the boiler flue gas, so that the discharge of flue gas with flow rate in line with environmental standards. With the  emphasis on environmental protection by the country, the application of calcium hydroxide will bring economic and social benefits at the same time. The application will be more extensive and the development prospect is very broad.
 
Although Chinese calcium hydroxide industry has developed rapidly, compared with foreign developed countries and regions, there is a big gap in the development of calcium hydroxide industry in China. Advanced calcium hydroxide production enterprises in foreign countries have achieved industrial scale and refinement, basically adopting high-efficiency energy-saving large-scale equipment and advanced production technology. At present, the overall size of calcium hydroxide production enterprises in China is small, and the scale of the industry is low; the degree of product finishing is low, and the refined products are in short supply. The products cannot meet the large demand of major industries such as power plant desulfurization, fine chemicals, pharmaceuticals, food, petroleum, and paper-making, etc. ; In addition, due to the low level of processing equipment and technology, deep processing equipment and technology lag behind, raw material utilization is low.
 
Therefore, domestic enterprises should actively carry out technological innovations, and conduct targeted improvement and improvement of the calcium hydroxide production equipment in terms of appearance, feed volume, airflow, slag discharge, and dust removal. Optimized combination of rational selection of system equipment and process design, advanced system process electrical control system to ensure stable operation of the system and stable product quality, so that the product meets the environmental protection requirements of the national environmental protection department.