In the Leaching process of Aluminium, alumina present in bauxite dissolves forming a soluble sodium aluminate. The impurites are filtered off. The filtrate is diluted and a little freshly precipitated aluminium hydroxide is added which causes the precipitaion of aluminium hydroxide. How does it cause the precipitation of aluminium hydroxide? According to Le Chatelier's Principle backward reaction will occur consuming aluminium hydroxide. What is the actual reason?