Study On The Natural Volatilization And Cluster Structures Of Industrial Pickling Solution

Industrial pickling use plently of hydrofluoric acid, hydrochloric acid, sulfuric acid, nitric acid, and so on to keep iron, chromium and nickel into ions dissolving out from the oxide coating on the surface of the steel and the steel. Pickling process is accompanied by evaporation of acid mist, it serious damage physical mental health of the production operator, the environmental pollution is especially serious. The key technical problem to be solved is how to control the generation and transmission of acid mist effective in the first time aim aiming at volatilization of the large area of acid mist in industrial pickling. However, the research about industrial acid liquid during natural volatilization process there was rarely reported at home and abroad.The hydrochloric acid, sulfuric acid, nitric acid, was researched. Temperature was the main influencing factors of the volatilization. The experiment were conducted 400mins in temperature of 5℃ to 80℃. The rule of volatilization were studied by measured the concentration, calculated the mass transfer coefficient and the mass transfer rate. This paper also studies the natural volatile situation of hydrochloric acid pickling while simulated the pickling condition of industrial pickling solution by measuring the change law of solution concentration varies with time to discuss the influences of the concentration of ferrous ion on acid liquid volatilization; On the basis of the research, this paper studies natural evaporation process of hydrochloric acid, sulfuric acid and nitric acid added with heterogeneous liquid membrane at different temperatures. The changes of the cluster structures of hydrochloric acid and hydrochloric acid pickling were calculated by Gausssian03. The mechanism of generation and transmission of the volatilization of acid liquor was researched from energy barrier angle.The results showed that the volatilization of hydrochloric acid and nitric acid was strengthened as the increases of temperature. But the evaporation rate has significant regional in temperature. Because of strong water imbibition, the concentration of sulfuric acid in the beginning fall quickly then back to balance. The energy required in the process of the change of cluster structures was calculated. Results showed that:The volatilization of hydrochloric acid was gradually slow down and then gets faster. Because of the volatilization of hydrochloric acid was a physical process with hydrochloric gas escaping the surface diffusion into the air; The volatilization of sulfuric acid was a physical process for the water imbibition was greater than the process of volatile; The volatilization of nitric acid was a chemical process for the effect of gas of NO2 evaporating into the air constantly. With the increasing of the ferrous ion concentration, the more increasing of the salt effect, the more stability of molecular clusters, which promote the volatilization of hydrochloric acid. The acid suppression effect of acid liquid added with heterogeneous film is obviously different, as the different membrane concentration and temperature.