Research On Treatment And Recovery Technology Of Stripping Waste From Aluminum Profile

Aluminum profiles dissolution with sodium hydroxide, obtaining alloy aluminum, produced some high alumina alkaline mixture in the production process. The moldboard was washed with alkaline clean water, leaving the stripping waste with the main component of sodium hydroxide and sodium aluminate. For the above stripping waste, it not only consumed a large number of acids to adjust pH value. If measures were not taken to recycle, the aluminum compound created a huge waste of resources. So the treatment of stripping waste was an urgent problem. If the stripping waste was comprehensively utilized, it not only can reuse it, but still protect the environment. It has great realistic meaning and application prospect.This article mainly studied the treatment method in the process of producing aluminum produced by a large number of high aluminum alkaline waste and used refined lime to solve the problem. A detailed study was conducted about initial aluminate concentration, method of adding refined lime dose, reaction time and stirring rate of influencing factors on the aluminate removal and the recycle efficiency of alkali in various initial concentration of aluminate. The study concluded the proper technical parameter and analysed the mechanism of refined lime processing stripping waste. At the same time, by studying the relationship between adsorption quantity and time, the reaction kinetics were put forward.The results showed when refined lime treat the stripping waste for removing aluminum and recovering sodium hydroxide, the optimum parameters were stirring rate 300r/min with molar ratio(S/L=3:2) after 1h treatment. The removal efficiency of aluminate is 94% for high initial aluminate concentration of 3.245 M and the removal efficiency of alkali is more than 80%, which can be repeated use. Both X-ray diffractometer(XRD) and Scanning electron micrographs(SEM) were employed to characterize the structure features of the hydrated lime and adsorbates. The research confirmed that aluminate removal was mainly due to the adsorption. It was fitted to pseudo-second-order reaction kinetics well.The achievement of research enables recycling of the stripping waste, which was not only save costs but also protect the environment, so it has obvious economic benefits and good prospects.