Mining by-products could help WA manage its acid-saline drainage

A report published by the Cooperative Research Centre for Landscape Environments and Mineral Exploration (LEME), has found that by-products from steel smelting and bauxite processing could be used to neutralise acidic waters in drains built to manage the spread of salinity in the State’s wheatbelt.
 
In recent years, drains have been put in parts of the Western Australian Wheatbelt to reduce watertable levels and limit salt remobilisation and salinity. Their success has prompted the idea of building larger drains in the region.
 
Geochemical studies into the water composition of these drains have revealed high levels of acidity and elevated concentrations of trace metals in many drains, which can pose a risk to surrounding environments.
 
To investigate what options are available to reduce these risks, LEME was tasked to head the Wheatbelt Drainage Geochemical Risk Assessment Project commissioned by the National Action Plan for Salinity and Water Quality (NAPSWQ) and the WA Engineering Evaluation Initiative with support from the WA Departments of Water,
and Agriculture and Food, to provide a short review of the scientific literature.  
 
Senior researcher Dr Grant Douglas (CSIRO Land and Water) said the review has recognised the potential of steel smelting by-products and red mud, created during the processing of bauxite, to reduce acidity in drain waters.  
 
“The steel-making by-product has a high capacity to neutralise acid and potential to absorb a variety of trace elements. Oxide-rich red mud, which is strongly alkaline, could also be used to neutralise acidity and bind phosphorus,” Dr Douglas said.
 
“More detailed investigations are needed to assess the viability of using these materials before any decisions can be made.”
 
Project outcomes can be viewed in Open File Report 209, A Synopsis of Potential Amendments and Techniques for the Neutralisation of Acidic Drainage Waters in the Western Australian Wheatbelt.  A hard copy of the report is available for $6 plus postage and packaging, or downloaded electronically from www.crcleme.org.au.
 
Media Contact: Greg Lawrence, tel: +61 8 6436 8786, fax: +61 8 6436 8560 email:
[email protected]. mob: 0438 492 467. website: http://crcleme.org.au