The Study Of Mercury Control Technology For A 800 Thousand Tons PVC Resin Enterprises By Calcium Carbide Process

In recent years, the domestic calcium carbide method PVC enterprises have developed rapidly and played a more and more important role in the national economy. However, mercuric chloride, the catalyst in PVC production process, has some negative impact on the environment and human health. This paper focus on the research of the source of mercury and its compounds, technical process, as well as control technologies for a 800000 tons of PVC enterprise by calcium carbide method in xinjiang province. The status of mercury pollution control technology was analyzed firstly. The new optimized technical ideas were put forward to reducing the risk of mercury pollution and demonstrated the effectiveness of the prevention and control of the improvement. The main work was as follows:1. It is feasible to use low mercury catalyst as the modified catalyst. The results showed that low mercury catalyst almost has the same catalytic activity, life, and consumption performance compared with high mercury catalyst. The optimum operating temperature of low mercury catalyst is in the range of 140? to160?,and the water content in feed gas should be kept below 50 PPM.2. The waste acid depth desorption technique can completely solve the bottleneck problem of the current process technology, that waste acid with mercury could not be completely recovered from the waste acid. Through the actual operation data analysis, the optimal operation parameters of were found. The temperature of bottom tower should be kept in the range of 130? to140?. As Calcium chloride brine concentration in 48 to 52%, the waste acid processing capacity and index reach the best.3. The mercuric chloride content in the wastewater is lower than 5 ug/L after deal by using waste water double-effect evaporation combined with high efficient activated carbon adsorption technology, the mercuric chloride content in salt is lower than the national standard value. It is very simple to deal with, and reduce environmental risks. The optimal control parameters of the device PH around 8 to 10, pressure-60-70 kpa.4. It has put forward that control the risks of mercury involved in the production process including carry out identification, monitoring, physical examination, standardized operation and so on and has make technical improvement measures from the production process conditions, production methods, working environment, personal protection, etc.This paper studied on the mercury waste acid, wastewater containing mercury, low mercury catalyst and control of occupational health protection of pollution prevention and protection technique, production bottlenecks and compared and analyzed the production bottleneck data. Through summarizing the problems after the operation of the device, put forward specific technical solutions, it provided the suggestions and references for the development of mercury pollution prevention and control technology of PVC enterprises.