| Steel is widely used in infrastructure, industrial equipment manufacturing and people’s daily lives. But steel is easy to be rusted, which needs anticorrosive treatment before use. Currently, the companies mainly use hydrochloric acid at room temperature to get rid of rust. The concentration of Hydrochloric acid is generally about20%, and such high concentrations of hydrochloric acid will produce a lot of mist and affect the working environment and cause corrosion of equipment. The system of FeCl3-HCl can avoid similar problems, but the cost is relatively high. For this reason, this paper have studied the circulatory and recycling rust of the FeCl3-HCl system and designed relevant equipment.First, this paper aims to find a less measurement error method about concentration of ion.This paper adopts titration with potassium dichromate, phenanthroline spectrophotometer and EDTA titration to measure iron ions in the original solution, with the results compared, which proves that the potassium dichromate titration error is relatively small. Ultimately, the potassium dichromate titration was chosen to measure iron ion concentration.After choosing measuring method, by comparison of conversion rate of the different Fe2+oxidation catalyst, and surface quality and substrate roughness of renewable rust removal liquid sample, this paper decides the way of recycling and oxidation about the waste liquid:with sodium nitrite as a catalyst and air to oxidation, the capacity of the catalytic oxidation of liquid equals to that of the original solution.This paper also designs the process technological of the FeCl3-HCl system and relevant equipment. The size of rust removal slot is3m×2m×1m, with glass fiber reinforced plastics as lining material and concrete as shell. The size of reegeneration reaction vessel is1600mm×4000mm, with glass fiber reinforced plastics as lining material and Q235as shell. As sealed containers with gas would produce a certain pressure, a pressure gauge is installed at the top of the tank. The system is designed to achieve the waste recycling and reduce harmful gas pollution to the environment. |
