There are sulfuric acid method and chlorination process for the titanium pigment production. Although the chlorination process has been agreed by insiders as the mainstream oftitanium pigment process, the reality is that, in China, we are mainly adopting sulfuric acid method at the present stage. Because the cost of sulfuric acid method titanium pigment is low, and the process is easy to understand, with various product type, it has occupied a large market share. However, there is a big problem with sulfuric acid process to achieve energy conservation and emissions reduction. The key is flue-gas treatment, waste heat utilization, and the comprehensive utilization of waste acid. At present our company is mainly involved in titanium pigment production flue-gas treatment process.

For sulfuric acid method titanium pigment production, the acidolysis process includes solid phase method, liquid phase method and two-phase method, and the main domestic titanium pigment production enterprises adopts solid phase acidolysis process.

Solid phase method has the following disadvantages:

①High reaction temperature, which has high requirements to the heat resistance and anticorrosion of the equipment requirement, including the reaction kettle and exhaust pipes;

②It has certain requirements on mineral powder

③Violent reaction, instantaneous produces a large amount of exhaust gas, which is difficult to handle.

According to different requirements of the acidolysis operation: reaction, mature, cooling, leaching, and reduction on tail gas exhaust systems, our company has developed acidolysis tail gas treatment equipment. It was first used on Fangyuan titanium pigment production line in Wuhan Qianjiang, and achieved preliminary success. Then it was used in Huai'an Feiyang titanium pigment, Shanghai Pengbo titanium pigment and other enterprises, the results were good. This technology becomes more and more perfect in practical use, and the experience has been accumulated, especially in the following aspects:

(1)Acidolysis pot cover liner performance improvement to resist 93% sulfuric acid

(2)Structure improvement for washing absorption tower

(3)Structure improvement for venturi scrubber ;

(4)The accuracy improvement of fan air flow calculation

(5)The optimization of ERP equipment resin selection

1.Execution standard for sulfuric acid method titanium dioxide industry acidolysis exhaust

Execution standard: GB16297-1996

The Integrated Emission Standard of Air Pollutants：

The data are as follows:

Serial number	stack height m	maximum allowable emission concentration mg/m3		Standard requirement Kg/hr
		maximum allowable emission concentration mg/m3		Secondary level area			Third level area
		sulfuric acid mist	particulate matter	sulfuric acid mist	particulate matter	sulfuric acid mist	particulate matter
1	40				39		59
2	50	≤45	≤120	23	60	35	94
3	60	≤45	≤120	33	85	50	130
4	70	≤45	≤120	46		70
5	80	≤45	≤120	63		95