The Development And Application Of Neutral Derusting Agent

Traditional acid rust remover is formulated with a variety of strong acids together. The kind of rust remover is very popular because it has the advantages:Rapid rust remover rate,low cost and removing completely. Hovever, strong acid belongs to the hazardous chemicals of state strictly controls and it is very dangerous to human body. What's more, it results in many issues in the process of rust removing, such as metal corrosion, hydrogen embrittlement, environment-polluted and it is easy to rust again. So it is very significant for the development of safety and environmental-friendly neutral rust remover for the pickling industry.In this paper, it developes a neutral (or weakly acidic) rust agent by aorthogonal experiment and single factor test and analyzes its performance. This paper explores the influence of temperature on rust remover derusting rate, it found that as the temperature rising, the rate increases. Use it to remove the rust of Q235 which level is class C, when temperature is 25?,the rate is 1.54×102 g·h-1·m-2, and it takes 23 minutes to clean thoroughly; Raise the temperature to 80?, the rate is 4.73×102 g·h-1·m-2, and it takes 10 minutes to clean. It found that this rust remover was similar to the product of company in normal temperature, and when we raise the temperature, it's descaling effect is significantly higher than the company product, but they are not as good as hydrochloric acid. In addition,this paper explores the effect of ultrasonic, it found that the ultrasonic has no obvious influence on the rate of rust removal,when we raise the temperature,rust removal rate increased significantly with the increase of ultrasonic power, rust removal rate can reach 9.85×102 g·h-1·m-2 in 80? when the ultrasonic power is 100%, it's rate catch up with the hydrochloric acid, and rub it completely within 5 minutes. Besides, this paper explores the effect of it's rust protection with SEM,it found that it formed a thin film on the surface of Q23 5, the film has the effect of rust protection,and the rust don't return in the room in a week. This paper determined the Tafel curves of rust removal by electrochemical workstation from the point of electrochemical principle of evaluation. It found that the rust remover's ability to dissolve metal oxide is better than hydrochloric acid, and it is more advantageous to rust material loss on the steel plate surface.The pH of the environment-friendly descaling agent is 5.8-6.8, it closes to neutral and it will not cause corrosion of the equipment, which has many virtues, such as high efficiency and safety, at the same time, it has function of rust-removing and inactivation, it is not easy to return after rust,etc. It is a environmental-friendly multi-purpose deruster in a new generation.