The red mud by-product of Bayer process bauxite/alumina refining is extremely caustic, difficult, and expensive to treat with traditional technologies.  ESS  has created and demonstrated solutions for red mud and associated leachate. The solution comprises multiple  SABR reactors utilising multiple biological manifolds or SABR symbiotic columns to effect remediation. 

Dealing with Red Mud Waste

The financial cost and environmental risk of red mud waste and associated effluent historically and currently a significant issue, now has an  economic, environmentally and societally acceptable solution. Earth Sustaining Sciences has demonstrated  the ability to ameliorate red mud delivering multiple beneficial solutions utilising the SABR process.

The cost benefits of using biosecure, all-natural endemic biological solutions in existing or constructed shallow dams or tank/closed systems to treat red mud effluent are significant. Further, ESS  are able to in-situ leach treat red mud stockpiles and dams to improve the effluent contaminant values allowing polishing through external SABR systems allowing reduced residency in the remediation process. This develops commercially acceptable applications for the treated red mud as agricultural and civil construction reducing the volume of at-risk waste, while providing secondary value for naturally treated red mud as a commercially viable product.

The neutralising effect of the SABR system on red mud and associated effluent is demonstrated in the following graphed information.

The Effect of Degrees of Neutralisation and Potential Commercial Gain

The ability of the SABR Process to achieve remediation of red mud and associated effluent reducing the pH from up to 14pH to as low as 6.1 pH is the new reality reality in bauxite/alumina processing residue solutions.  If red mud is completely neutralised, through the  SABR process, (7 pH) the commodity no longer remains a risk and becomes available for secondary utilisation as a commercial asset. The neutralisation demonstrated was achieved at flow rates an order of magnitude higher than would be normal in an operational system This was performed to identify potential failure characteristics following the initial demonstration of ability in a 7-day trial process to prove ability. The potential for SABR biological  liquors as all-natural solutions utilised in flushing red mud stockpiles and tailings dams, in a primary remediation process in difficult locations is significant. It is considered to progress the partially treated effluents into SABR systems improving the precipitation of contaminants and continually reducing insitu risk while continually treating. It should be noted that at 7 pH the majority of alkali soluble metals will be removed from the effluent however, should some metal species remain in solution the SABR system has the ability to drop the pH well into the acid range then return the liquor to neutral; bio-stripping metals to levels allowing regulator approved water release.

Furthermore, it is important to realise that the effective process requires no chemical dosing, minimal to no additional pumping, and uses no costly or energy intensive RO or ion exchange stages. The process is self-sustaining, low cost, low energy, self-stabilising and requires minimal servicing.