In the alumina production process of Bayer's method,sintering method or combination method for the treatment of duraluminite monohydrate,bauxite trihydrate or mixed bauxite,the mineral is first crushed and crushed to less than 1mm.Concentrated sodium hydroxide is then added and subjected to high temperature and pressure.Aluminum dissolves in highly corrosive liquids,while impurities other than soluble silicon are not dissolved.After the above process,the gravel is removed along with the slurry that has undergone primary concentration and precipitation.Anionic polyacrylamide flocculants were added to the primary concentration tank.This is a very important process for clarifying overflow.The bottom flow of the thickening tank,the red mud,will be treated by a reverse reflux settling process.In this process,the aluminum in the liquid is recovered through a series of washing sedimentation tanks.At this point the anionic polyacrylamide flocculant is used again to promote rapid sedimentation and obtain a clear overflow that meets the requirements.

The aluminium-rich primary concentration tank overflows through filtration,cooling(48 hours),and filled with aluminum hydrate to promote the precipitation of aluminum trihydrate.Aluminum is calcined by filtration and washing.