Dust Pollution Characteristics And Control Technology In A Steel Plant

With the rapid development of the steel industry,China’s steel production has increased year by year,China has became the largest steel producer and consumer in the world.However,in the process of steel production and processing,the dust and air pollutants in the smoke produced by smelting escape through the equipment into the workshop,polluting the workshop environment,corroding the equipment,and endangering the health of workers.Based on field investigation and engineering analysis of a certain steel plant,sampling were carried out in the workshop to analyze the concentration,source and pollution characteristics of dust pollutants in the workshop environment of each section,and key control points of pollutant hazard were found.Excel,origin8.0 and other software were used for data processing and statistical analysis to comprehensively evaluate the distribution characteristics of dust pollutants in the workshop and the change of dust concentration in the workshop after improvement.The following conclusions are drawn:The environmental dust in the workshop of iron and steel includes the dust,fluorite mixed dust and silica dust produced in the sintering workshop during crushing,screening,sintering process,blast furnace ironmaking,converter steelmaking and rolling workshop operation.Dust and sulfur dioxide pollution in the workshop environment is mainly concentrated in the sintering workshop,and the concentration range of dust from 2017-2019 is 2.03-7.50 mg/m3,2.55-6.83mg/m3,1.77-15.27mg/m3 in order.The dust concentration of the three sampling points of the disc feeder,single-roll crusher and vibrating screen increased significantly,approaching the Permissible concentration-Time Weighted Average(PC-STEL).The main control points of the ironmaking workshop were the sinter ore,pellet ore feeder and Emission of dust from the blast furnace body platform;from 2017 to 2019,the dust concentration at the back platform of the steelmaking workshop reached the highest,was 11.89 mg/m3,10.57 mg/m3,and 8.93 1g/m3 respectively,became the key control parts of dust pollution in the steelmaking workshop:The steel rolling workshop dust concentration in the air is controlled within 4.89 mg/m3,which all meet the occupational exposure limit,and mainly controls of the dust pollution is the roughing mill and the intermediate rolling mill.According to the dust detection results,the workshop’s corresponding dust control facilities were improved according to the main pollution control points of the workshop:in 2019,activated carbon was introduced into the existing semi-dry desulfurization treatment process of the sintering workshop,and an electric dust collector was added to the tail of the machine to reduce the batch room disk.The dust concentration at the feeder,single-roll crusher,and vibrating screen;in 2018,a humidifier and a mist water pipe dust removal device were added to the dust in the iron making workshop and coated with heavy anti-corrosion paint on the inner wall of the pipeline to suppress corrosion of the pipeline equipment,sintered ore,ball The dust concentration at the point of the pellet feeder was reduced from 5.60 mg/m3 to 4.54 mg/m3,and the concentration of the blast furnace body platform was reduced from 5.72 mg/m3 to 4.57 mg/m3;the converter’s steelmaking workshop added a total of 1 million air volume in 2018 The Nm3/h triple negative pressure dust removal system reduced the dust concentration at various points in the workshop to various degrees.The concentration of the platform control point after the converter was reduced from 10.57 mg/m3 to 8.93 mg/m3;in 2017,the axial rolling fan was installed in the steel rolling workshop And spraying and spraying dust removal devices,accelerated cooling in 18-19,and the spot dust concentration of rough rolling mills all declined slightly.For the hazards of workshop dust,each workshop of the iron and steel plant has adopted a series of management measures to set up corresponding protective facilities for the types and sources of pollutants;implement systematic occupational health monitoring for employees on duty,and wear qualified personal hygiene protective equipment as required;Establish an environmental safety management agency and continuously improve the environmental management system.