Bena Terra Resources LLC (BenaTerra) is a wholly-owned USA subsidiary of Rodinia Resources Pty Ltd (Rodinia), an Australian domiciled company. Rodinia was incorporated in 2008 and established a presence in Jamaica at that time. Rodinia’s initial focus was potentially attractive mineral resource exploration opportunities in Australia and Jamaica. However, arising from its activities in Jamaica, where a great deal of bauxite is mined and processed, or exported, Rodinia became aware of the environmental challenges arising from the processing of bauxite to alumina tailings – known as red muds – and the urgent need to remediate massive volumes of red muds around the world.
Since 2012 Rodinia has been developing its own unique technology for the biorehabilitation of red muds that are stored in dams or other impoundments (tailings dams) during and after mine closure, to produce an engineered soil known as Technosol. Rodinia has progressed its work in both Australia and Jamaica to the point of proof of concept and lodgement of a patent application.
Bio-neutralisation testing on Jamaican sourced red muds has been carried out at the University of Queensland, Australia. Further, test work on the post Bio-neutralised muds for the extraction of valuable strategic metals, has been carried out by Australian Minmet Metallurgical Laboratories Pty Ltd (AMML), at Gosford in Australia. Rodinia is now moving to advanced scale test work, which if successful, will lead to onsite pilot plant processing and commercialization.
Our team has additional experience in characterization and process development for sulphide mine tailings. Dr Will Goodall has assessed over 20 tailings dams for re-processing potential and has been closely involved with process development for the Cleveland Sn-Cu tailings reprocessing project in Tasmania, Australia.
Similar processes to Rodinia’s technology have been used in the partial remediation of Red Muds (e.g Mt Rosser, Jamaica). These examples involve in-situ addition of biomass to Red Mud dams, promoting natural microbial activity. The result is a remediated ‘cap’ of 1-2m depth, which over a period of years improves to a point where vegetation can be grown.
These results have reinforced and confirmed Rodinia’s belief that full remediation of tailings dams is achievable through its biorehabilitation process. Our primary difference is that we process the Red Muds in external reactors, greatly accelerating the process and allowing the potential for rehabilitation of the entire Red Muds volume.
To obtain samples for testwork, we take manually operated auger samples and, where warranted, bulk samples are obtained using mechanical methods such as excavators.
Initial sampling requires only a few pounds of wet red mud. More extensive testwork still only requires samples sizes which can be less than a household bucket. Pilot plant testing, which is to be undertaken on site, involves multiple tons of material being processed through a small pilot plant for a limited period.
Off site, we test auger samples from representative areas of the Red Muds impoundments for mineral content and the applicability of various Biorehabilitation processing methodologies and processes subsequent to initial Technosol production. The eventual onsite tests will use the results from the off site test work, as well as related feasibility studies conducted primarily off site during the same period, and apply them on the actual site, initially at pilot plant scale.
During the feasibility and off site testing period no hazardous wastes will be generated. Pilot plant testing on-site is not expected to generate hazardous wastes, but if so they will be contained within the existing Tailings Dams.
Our rigorous phased testing and pilot plant program has a key aim to develop processes to eliminate hazardous tailings and, if present, economically produce valuable strategic metals, and in doing so generate minimal hazardous waste. Any hazardous waste produced will not be stored but will either be recycled within the Bioneutralisation circuit, creating a closed circuit, and/or permanently disposed of in accordance with relevant government legislation and permits.
As Red Muds are wet and our proposed Bioneutralisation and possible strategic metal extraction processes are wet processes, these should not create dust, which is a problem with many current Red Muds tailings dams. With respect to potential odours these will identified during the testing program and if they become an issue, proven mitigation processes will be adopted e.g. using methods such as those applied at sewage waste water plants.
Our operations, even at full scale commercial level, will be relatively small and have minimal effect on air quality, if at all. In any event we will be applying for any air permits mandated by relevant government authorities.
The plant is expected to consist of ponds/channels, which make up the cell biodigester, plus a number of tanks as well as stockpiles of organic inputs to the Bioneutralisation process and produced Technosol. The Technosol storage will comprise a curing stockpile, a pioneer crop field and final product stockpiles. It will have a relatively small ‘footprint’ similar to a few standard residential blocks and look like a combination of a beer distillery and fish ponds.
There are numerous negative outcomes. Firstly they will take up room that should be able to be used for other activities, particularly in light of increasing population density and land values. During dry periods, dust issues could be created due to the extremely small particle size of the Red Muds. There is also the risk of leaching into groundwater of the highly alkaline leachate, not to mention the possibility of catastrophic failure of a dam wall. The tailings dams, if left as is, will require monitoring and maintenance in perpetuity, which is a substantial long term cost to the community.