Abstract: The overspray generated by spraying in the painting workshop is treated with a flocculant to form paint slag,which has a moisture content of up to 80% to 95%. When treated as hazardous waste,most of it is wastewater,resulting in an increase in production costs. This article studies a comprehensive scheme to reduce the output of paint slag by gradually reducing the free moisture in the paint slag. Firstly,stable output of paint slag is achieved through automatic scraper slag removal equipment;Next,using a simple lifting drainage device,under the dual effects of gravity and squeezing pressure,after 12 hours of drainage,the moisture content of the paint slag is reduced to about 55%;Finally,the paint slag after being lifted and drained is dispersed on a porous stainless steel tray,placed inside a heat pump sealed low-temperature drying equipment,with a gradient temperature rise of up to 50 ℃. After 12 hours of circulating hot air drying,the moisture content of the paint slag is reduced to below 20%. After comprehensive treatment,the output of paint slag has been reduced by about 60%.

Key words: hazardous waste, paint slag, moisture content, lifting drainage, heat pump sealed low-temperature drying equipment