i. comprehensive utilization of titanium dioxide by-product gypsum
yunfu area is an important cement production base in china, which can reach 7 million tons per year. the amount of gypsum retarder to be added in cement production is about 600,000 tons. our company uses the abundant limestone resources of the post-sludge used by stone processing companies in yunfu area, and neutralizes the acid waste water produced from titanium dioxide to produce gypsum, which is used by cement plants. at present, our company has built 220,000 tons. annual gypsum production capacity, and according to the requirements of the cement plant, we further treat the gypsum after neutralization. the gypsum moisture content produced is less than 20%, and can be directly supplied to the cement plant as a raw material for the market, thereby completely solving the sulfuric acid method. the titanium dioxide production process is properly treated with waste water and waste residues. the processing cost increases by rmb 20-40/ton on the basis of neutralization.
second, the comprehensive utilization of ferrous sulfate heptahydrate
the use of titanium concentrate as a raw material for the production of sulphate titanium dioxide will generate 3-4 tons of ferrous sulfate heptahydrate per ton of titanium dioxide. how to properly handle such a large amount of ferrous iron is a problem faced by many companies. our company uses a variety of channels to deal with the solution: direct sales; pyrolysis sulfur pyrolysis; production of polyferric sulfate, at present, our company is still building a water ferrous sulfate plant, so that it will be better to burn to the system acid. through this series of treatment, the large amount of ferrous iron produced by our company's titanium dioxide production is not only a waste residue, but also serves as a raw material for our company's supporting facilities, and it has truly realized recycling.
third, the comprehensive utilization of waste acid
the amount of waste acid (sulfuric acid content 200-300gpl) produced in the sulphate process titanium dioxide is 5.0-6.0t/t-titanium dioxide. if it is not comprehensively utilized, the production cost will be greatly increased, so our company will greatly increase the production cost of titanium dioxide. according to the actual situation, the comprehensive utilization of waste acid has greatly saved the cost, and it has taken a new path for the recycling economy.
our company through technological innovation and improvement, my company's acid mine ratio 1.44-1.46:1 (for panxi region's ore source, production of anatase titanium dioxide), the use of waste acid to initiate the reaction and the use of waste acid to adjust the quality of titanium index. the amount of reuse can reach about 10%-20%.
the waste acid is sold to customers in a certain area, such as the manufacturers dealing with alkaline waste water, as well as the prices for sulphuric acid used for pickling steel products, as well as regional restrictions, and our company's export of waste acid reaches 30%-50 �tween.
in the project for the polymerization of ferric sulphate, in the project of polymerizing ferric sulphate, the waste acid was used instead of 98% for the production.
iv. comprehensive utilization of wastewater
sulfuric acid production in the production of titanium dioxide requires a lot of water, and the formation of sulfuric acid content of about 15gpl acidic wastewater 50-60t, these water can not be returned directly to the use of production, must be processed in multiple steps before they can be discharged and returned to use. the returned water is mainly used for floor flushing in workshops, greening of plants, acid treatment of tail gas, crystallization and enrichment of circulating supplementary water, and secondary spray of calcined exhaust gas.
v. strengthen the management of production organizations, increase the recovery rate of titanium, and reduce the amount of waste discharged
the company has established a three-in-one management system of quality, environment, health and safety, and has passed iso 9001:2008, iso 14001-2004 and gb/t28001:2001 standard certification. we have also established a strict enterprise management system. sound and effective management is the guarantee for all the details of the company's work. it is one of the guarantees for enterprises to win in the market competition.
we will strengthen the control of production processes and control the waste water, waste gas, waste slag and noise generated during the production process, and achieve discharge standards. strengthen the control of various process points and rely on scientific and technological innovation, improve the recovery rate of various points, and strengthen process control to ensure that the equipment is intact and is strictly prohibited.