Chlorinated titanium dioxide process in the domestic development is not only a technical problem

China Coatings Online News Information
Titanium white powder is currently the best performance of white pigments, is widely used in coatings, rubber, plastics, paper, printing ink and other fields. There are two processes for its production, sulphuric acid and chlorination. Because of its environmental protection and high product quality in the production process, the production process of titanium dioxide by chloride is an internationally recognized new generation of advanced technology to replace sulphuric acid.
two preparation methods
the current global production capacity ratio of titanium dioxide chloride and titanium dioxide sulfate is approximately 6:4. In developed countries in Europe and the United States, the rate of chlorination is higher. However, there are only a few titanium dioxide enterprises in China using chlorination method. Why didn't the domestic titanium dioxide industry develop?
Internationally recognized excellent technology, national memory dispute
It is understood that although there has been a conclusion in the international community, but in the Chinese industry, whether it is good sulphuric acid or chlorination, but there has been a great deal of controversy.
view of the two sides is to advocate the development of chlorination to eliminate sulphuric acid. Relevant professionals pointed out that China's titanium dioxide industry must take the path of chlorination, in order to have the strength to meet the serious challenges of the international market. The reason is very simple, sulfuric acid method of the main raw materials are sulfuric acid and titanium ore, etc. , the production of low product quality, single varieties, serious environmental pollution. On the contrary, the main raw materials of chlorination method are high titanium slag and chlorine gas, known as clean technology, with high degree of production automation, high product quality, large scale, "three waste" emissions and many other advantages.
view of the other side is that chlorination is not a complete substitute for sulphuric acid. At present, Europe and the United States in the paper, chemical fiber, ceramics, cosmetics and other industries on the production of titanium-type titanium dioxide sulfate method is still maintaining strong demand, sulfuric acid titanium dioxide powder in the future still has a wide range of applications and market demand, will be with chlorinated titanium white powder long-term co-exist.
, the domestic sulfuric acid method will not lag behind. Because domestic enterprises have made efforts to create an improved sulfuric acid method. The technology has been greatly improved compared with the original sulfuric acid method, such as the use of acid-soluble titanium slag instead of titanium concentrate as raw materials, the realization of waste acid concentration recycling, sulfuric acid residual heat utilization, production level has been greatly improved.
industry also said that in terms of environmental protection, simply said that sulfuric acid pollution is a serious misunderstanding. The main pollution of titanium dioxide by sulphuric acid is waste sulfuric acid, but at present, with the popularization of waste acid recovery technology, the amount of waste sulfur can be greatly reduced. For example, Sichuan Longyu Company, its waste acid is used in the production of phosphates. The chlorinated slag produced by chlorination method is difficult to treat, at present, many foreign enterprises will be chlorinated waste to the high seas deep sea abandoned, or buried in sparsely populated abandoned mines, more harmful to the environment;
to adapt to the chlorination process, titanium fine ore needs to be refined into high titanium slag. As a result, the production process of chlorination is not necessarily short and the cost is not necessarily low. A joint EU study of sulphuric acid methods has different environmental risks, not who is more environmentally friendly. Chlorination saves energy and reduces wastewater discharge, but its waste is more toxic than the waste produced by sulphuric acid.
in fact, in the titanium dioxide product type, improved sulfuric acid method also has advantages. Improved sulphuric acid method can produce high-end products of goldstone-type titanium dioxide can also produce low-end products of sharp titanium-type titanium dioxide, while chlorination can only produce gold-redstone-type titanium dioxide. Although it can also be converted to a sharp titanium type, additional processes are required during the conversion process, which adds additional costs.
Although the development of the general trend, the key technology difficult to master
after years of technical exploration and attack, the production process was cracked one by one, Jinzhou titanium industry finally in 2001 successfully developed China's first set of tons of chlorinated titanium dioxide core device - oxidation sensor, to solve the key technical problems. After 20 years of efforts, only gradually realized the completion of the plant put into operation, production and continuous operation.
the current domestic chlorination device compared with the advanced level abroad, there are still shortcomings. First, the operating cycle of domestic oxidation reactor is only more than 3 weeks, but compared with foreign oxidation reactor up to six or seven cycles, there is still a certain gap. Second, there is still a certain gap between product quality and foreign countries, mainly reflected in the granularity of titanium dioxide and crystalline control. Show whiteness, coloration, and masking. There are gaps in indicators such as weather resistance. Third, in the manufacture of key equipment, domestic manufacturing quality can not be compared with imported equipment. Fourth, there is still a gap between the production capacity of single equipment and foreign countries.
Plus chlorination method and sulfuric acid process process is very different, the former production technology and equipment material requirements are very high, and the vast majority of domestic enterprises can not reach this level of technology, at the same time we do not have their own independent core technology, key technology is difficult to introduce. This is also an important reason why chlorination method has not been popularized in China.
。