Purification with hydrocyclone on low grade Sodium-bentonite from Xinjiang, China

Bentonite need to be purified to get montmorillonite content more than 80 % for industrial applications. The screen analysis indicates that montmorillonite in two Sodium-bentonites, which come from Xiazijie, Xinjiang uygur autonomous region, China, distribute mainly in the size fraction of -400 mesh. In this size fraction, the montmorillonite contents are 61.8 % and 60.0 %, yields are 88.5 % and 90.0 %, and the recoveries are 96.7 % and 93.7 %, respectively. According to the results of X-ray diffraction(XRD) and screen test, the two bentonites can be mixed together to be purified. With the 1st stage hydrocyclone condition of pulp density 4 %, pressure 0.19 MPa, diameter of hydrocyclone 125mm, and with the 2nd stage hydrocyclone in the condition of pressure 0.12 MPa and diameter of hydrocyclone 75mm, the concentrate with montmorillonite content of 82.3%, yield of 48.8 % and recovery of 63.7 % can be got. The 2nd stage overflow product meets industry standard. The results show that hydrocyclone is the effective means for purification of this low grade Sodium-bentonite, but the Sodium-bentonite could be converted to Ca-bentonite after purification.