Application of sand mill in titanium dioxide production

Titanium dioxide is a commercial name, its chemical name is titanium dioxide, and its molecular formula is TiO2. Titanium dioxide has high refractive index, ideal particle size distribution, good covering power and coloring power. It is a kind of white chemical pigment with excellent performance. It is widely used in coatings, rubber, plastics, paper making, printing ink, daily chemical industry and other industries. In recent years, with the rapid development of China's national economy and the continuous improvement of people's living standards, titanium dioxide industry presents a rapid development trend.

Generally speaking, there are two main types of titanium dioxide production technology in China: sulfuric acid process and chlorination process. Because a large number of scab particles are produced in the process of chlorination titanium dioxide gas-phase oxidation, they cannot be completely dispersed in the beating process. If these scab particles are not sand ground, they will be directly coated in the coating process. After crushing by the steamer, the scab particles are incomplete and irregular in shape, which affects the product quality, It is an important reason for low dispersion and color difference of products. In order to solve this problem, screening experiments were carried out on oxidized incoming material and mortar after grinding to determine the number of scars and to study the role of grinder in the post-treatment process of titanium dioxide. The development of production technology of titanium dioxide in China has gone through three stages: the first stage is from the middle of 1950s to the end of 1970s. The annual production capacity of titanium dioxide in China is only 20,000 tons, and most of them are low-grade varieties. In 1978, the total output of titanium dioxide in China was less than 20,000 t, of which the proportion of pigmented titanium dioxide was less than 15% [1].This stage is characterized by backward technology and slow development.

The second stage started from the end of 1970s to the end of 1980s. The technical level of production process of titanium dioxide by sulfuric acid method has been rapidly developed, and anatase and rutile products have been produced one after another. The national capacity of titanium dioxide has increased dramatically from 20,000 t to 100,000 t.During this period, new breakthroughs in production technology of titanium dioxide by sulphuric acid method were achieved due to the scientific and technological key problem of comprehensive utilization of Panzhihua vanadium-titanium magnetite resources, which promoted the rapid improvement of technical level in production plant of titanium dioxide by sulphuric acid method in the middle of 1980s. And the third stage is from the 1990s to now, the production capacity and output have expanded year by year, the national titanium dioxide output reached 1.472 million tons in 2010. At the same time, new breakthroughs have been made in production technology. The large-scale production units of rutile titanium dioxide by sulfuric acid method imported from abroad have been put into operation successively, and the large-scale production units of titanium dioxide by chlorination method imported have been digested and absorbed in China, and have also been put into operation smoothly. The introduction and use of titanium dioxide production equipment not only improves the production technology of titanium dioxide in China, but also changes the backward situation that only small-scale workshop sulfuric acid production method and low-grade anatase titanium dioxide can be produced in China.