Fundamental Aspects of Carbonate and Bicarbonate Salt Flotation

  • Dr Orhan Ozdemir, Chemical Engineering Department, the University of Queensland, Brisbane, AUSTRALIA., Australia
  • Dr Cengiz Karaguzel, Department of Mining Engineering, Dumlupinar University, Kutahya, TURKEY., Turkey
  • Prof Anh Nguyen, Chemical Engineering Department, the University of Queensland, Brisbane, AUSTRALIA., Australia
  • Prof Mehmet Celik, Department of Mineral Processing Engineering, Istanbul Technical University, Istanbul, TURKEY., Turkey
  • Prof Jan Miller, Department of Metallurgical Engineering, University of Utah, Salt Lake City, USA., United States

    • Trona, Na2CO3.NaHCO3.2H2O, is mined as the primary source for sodium carbonate production in the United States. Recent studies have shown that flotation can be used for preprocessing trona ore to remove insoluble mineral contaminants for the production of soda ash. Flotation studies showed that strong flotation of NaHCO3 can be achieved with both anionic and cationic collectors, while Na2CO3 do not float well. The viscosity of brine solutions and interfacial water structure affect the flotation response of the carbonate salts. The analysis of interfacial water structure in saturated brines shows that Na2CO3 acts as a strong water structure maker, while NaHCO3 acts as a weak water structure maker. Bubble attachment experiments suggest that collector adsorption takes place at the surface of NaHCO3 for flotation; this is not the case for Na2CO3. Contact angle measurements indicated that the surface of Na2CO3 is hydrated to a great extent, whereas the NaHCO3 salt surface is less hydrated. These results show a strong correlation between the interfacial water structure and the contact angle of these salts. It is concluded that the interfacial water structure at the NaHCO3 surface has a lower stability which allows NaHCO3 flotation with both anionic and cationic collectors.