Enabling safe dry cake disposal of bauxite residue by deliquoring and washing with a membrane filter press

Dry cake disposal is the preferred technique for the disposal of bauxite residue, when considering environmental issues together with possible future utilisation of the solids. In order to perform dry cake disposal in an economical way, the deliquoring of the residue must be carried out efficiently, and it is also important to wash the obtained solids well to minimise the amount of soluble soda within the solids. The study presented in this article aims at detecting the most important variables influencing the deliquoring and washing of bauxite residue, performed with a horizontal membrane filter press and by determining the optimal washing conditions. The results obtained from pilot-scale experiments are evaluated by considering the properties of the solids, for instance, the residual alkali and aluminium content, as well as the consumption of wash liquid. Two different cake washing techniques, namely classic washing and channel washing, are also used and their performances compared. The results show that cake washing can be performed successfully in a horizontal membrane filter press, and significant improvements in the recovery of alkali and aluminium can be achieved compared with pressure filtration carried out without washing, or especially compared with the more traditionally used vacuum filtration.

[1]  D. V. Boger,et al.  Application of rheology to solving tailings disposal problems , 1998 .

[2]  B. K. Satapathy,et al.  Production of pig iron from red mud waste fines using thermal plasma technology , 2012, International Journal of Minerals, Metallurgy, and Materials.

[3]  Markus Gräfe,et al.  Bauxite residue issues: IV. Old obstacles and new pathways for in situ residue bioremediation , 2011 .

[4]  G. Power,et al.  Bauxite residue issues: III. Alkalinity and associated chemistry , 2011 .

[5]  Li Zhong,et al.  Extraction of alumina and sodium oxide from red mud by a mild hydro-chemical process. , 2009, Journal of hazardous materials.

[6]  B. Whittington.  The chemistry of CaO and Ca(OH)2 relating to the Bayer process , 1996 .

[7]  Ravi Naidu,et al.  Hidden values in bauxite residue (red mud): recovery of metals. , 2014, Waste management.

[8]  David V. Boger,et al.  Environmental rheology for waste minimisation in the minerals industry , 2002 .

[9]  LorettaY Li,et al.  Effect of bauxite properties on the settling of red mud , 1996 .

[10]  M. Tadé,et al.  Novel applications of red mud as coagulant, adsorbent and catalyst for environmentally benign processes. , 2008, Chemosphere.

[11]  Américo Borges,et al.  Cleaner red mud residue production at an alumina plant by applying experimental design techniques in the filtration stage , 2011 .

[12]  Maneesh Singh,et al.  Preparation of special cements from red mud , 1996 .

[13]  C. Cremisini,et al.  Reuse of a treated red mud bauxite waste: studies on environmental compatibility. , 2005, Journal of hazardous materials.

[14]  L Y Li,et al.  A study of iron mineral transformation to reduce red mud tailings. , 2001, Waste management.

[15]  Justin S. J. Hargreaves,et al.  Conversion of Large Scale Wastes into Value-added Products , 2013 .

[16]  H. S. Altundoğan,et al.  Arsenic adsorption from aqueous solutions by activated red mud. , 2002, Waste management.

[17]  D. J. Cooling,et al.  Improving the Sustainability of Residue Management Practices — Alcoa World Alumina Australia , 2007 .

[18]  Indrani Ghosh,et al.  Leaching of metals from fresh and sintered red mud. , 2011, Journal of hazardous materials.

[19]  Suresh K. Bhargava,et al.  The surface chemistry of Bayer process solids: a review , 1999 .

[20]  M. Clark,et al.  Alkalinity conversion of bauxite refinery residues by neutralization. , 2010, Journal of hazardous materials.

[21]  J. Blais,et al.  Transformation of red mud from aluminium industry into a coagulant for wastewater treatment , 2008 .

[22]  E. Tütem,et al.  Heavy metal cation retention by unconventional sorbents (red muds and fly ashes) , 1998 .

[23]  Craig Klauber,et al.  Bauxite residue issues: I. Current management, disposal and storage practices , 2011 .

[24]  R. Boumaza,et al.  Development of a pozzolanic pigment from red mud , 1997 .

[25]  G. Power,et al.  Bauxite residue issues: II. options for residue utilization , 2011 .

[26]  肖伟,et al.  Recovery of alumina and ferric oxide from Bayer red mud rich in iron by reduction sintering , 2009 .

[27]  Dong-Yan Liu,et al.  Stockpiling and Comprehensive Utilization of Red Mud Research Progress , 2012, Materials.