Development And Application Of New Technology For Solution Leaching Treatment And Recovery Of Waste Spraying Hangers

In this study,the waste spraying hangers produced on the surface spraying production line of automobile,refrigerator and other electrical components are taken as the research object.After analyzing the generation and treatment of the waste spraying hangers,and considering the actual situation of resource recovery and utilization and enterprise production,two processes,i.e.,concentrated sulfuric acid leaching and sand blasting,are determined from the point of view of "resource utilization and harmlessness" of hazardous wastes.The effective removal test of the paint film on the surface of hanger was carried out.The removal mechanism of the paint film was studied,and the removal effect of the paint film under different conditions was investigated.Experiments show that concentrated sulfuric acid can effectively remove paint film on various hangers,and the removal rate increases with the increase of sulfuric acid concentration.Appropriate heating and stirring are conducive to the rapid removal of paint film.In addition,the test also shows that using concentrated sulfuric acid as paint remover has good recyclability.However,with the increase of recycling times,the concentration of sulphuric acid in solution decreases gradually,which has a certain impact on the removal of paint film on hangers.Therefore,it is necessary to supplement concentrated sulphuric acid to the system in time and separate paint residue in time.Because concentrated sulfuric acid is less corrosive to the base material of hanger,it is better to regenerate hanger with concentrated sulfuric acid as paint remover.After physicochemical and biochemical treatment,the supernatant can be discharged up to the standard.The sludge is safely landfill after concentration and solidification.Sandblasting process is a method that uses high-pressure air to eject abrasives from the nozzle of the gun,and uses the impact of high-speed air-sand flow,friction and shear of abrasives to clean the surface of hanger.Experiments show that sand blasting can effectively remove the paint film on the surface of some types of hangers.The effect of sand blasting is related to the abrasive material,particle size,injection pressure and injection distance.In this study,different abrasives were selected to carry out comparative experiments.It was found that the steel slag treatment had the best effect.From another point of view,it realized the recycling of steel slag resources,and at the same time,it was economical and environmentally friendly.On this basis,the effects of different particle sizes,injection pressure,injection time and injection distance on the experimental results were investigated with steel slag as abrasive.Starting from the optimum conditions obtained from the experiments,this paper summarizes the technological process of removing the waste suspension paint film with concentrated sulfuric acid and the technological process of removing the waste spraying suspension paint film with steel slag sandblasting method,with a view to providing reference for future industrial application.