WATER MANAGEMENT
of IDE Water Solutions in the USA on the topic of sulphates in mining . She stated : " Current regulations on mine water discharge for the mining industry vary , but are generally becoming more stringent worldwide due to environmental concerns . These regulations demand treatment solutions that can handle high sulphate concentrations commonly found in mineimpacted waters ."
Mine water discharge often comes with high sulphates , and when regulations require treatment for other constituents , such as selenium , chlorides and nitrates , sulphate will impede the performance of membrane-based treatment systems .
Niechcial says conventional treatment methods such as HDS and lime addition still require membrane processes to further treat constituents of concern . This gap necessitates alternative technologies that can bridge the disparity between treatment outcomes and the comprehensive regulatory demands .
One major issue with these conventional treatments is gypsum ( calcium sulphate ) saturation . The effluent from lime treatment and HDS is typically already saturated with gypsum , which significantly increases the risk of scaling when using downstream membrane-based technologies like reverse osmosis ( RO ). This gypsum scaling can clog membranes , reducing system efficiency , shortening membrane lifespan , and requiring frequent maintenance .
IDE Technologies addresses these challenges with its MAX H2O Desalter technology , which combines reverse osmosis ( RO ) with an integrated salt precipitation unit . This system enhances sulphate removal efficiency and handles variations in water quality , which are common in mining operations . Unlike traditional methods that struggle with gypsum scaling and high operational costs , the MAX H2O Desalter reduces scaling potential by managing the precipitation of sparingly soluble salts during the treatment process .
The operational benefits of the MAX H2O Desalter are substantial . It achieves high recovery rates , minimising waste and enhancing water reuse opportunities . It also lowers chemical usage and sludge production , resulting in reduced operational costs . The technology provides a robust solution adaptable to the fluctuating qualities of mine water , making it an optimal choice for mining operations looking to comply with stringent environmental regulations while controlling costs .
The MAX H2O Desalter has shown the capability to achieve recovery rates up to 98 %, with significant reductions in total dissolved solids ( TDS ) and sulphate concentrations . In a recent case study in one of the largest zinc mining facilities in Udaipur , India , the 1,296
MAX H2O Desalter recently deployed at a zinc mining facility in India
m 3 / day MaxH2O Desalter plant achieved an impressive 92 % water recovery rate .
These results IDE says highlight the MAX H2O Desalter ’ s robust potential to bridge the gap between current water treatment outcomes and the stringent environmental regulations in the mining industry . This streamlined approach not only aligns with prevailing environmental standards but also enhances operational efficiency . Moreover , its flexibility in adapting to variable mine water conditions and its reliable performance under diverse operational demands underscore its critical role in advancing the mining sector ’ s sustainability goals .
Automated large-scale risk assessment to quantify mining ’ s water quality impacts
Nigel Moon , Principal Water Resources Engineer
and Sarah Luu , Senior Water Resources Engineer , both with WSP , recently explained how the company harnessed automation to help a large mining client in Australia to better manage water quality risks , with the project still ongoing .
They state : “ Many of our mining clients operate in water-scarce areas and in complex , dynamic catchments which can change throughout the life of the mine . For sustainable operations , our mining clients must optimise water use , maintain water quality standards , minimise erosion and sedimentation , and adapt to the pressures of climate change . In this project , our mining client needed to demonstrate to regulators that it was managing water quality risks associated with its operations , particularly due to surface water runoff interacting with sensitive downstream receptors . Additionally . the water quality is influenced by complex interdependencies . This made it challenging to demonstrate regulatory compliance using conventional approaches .”
As a solution , WSP proposed an innovative , automated , GIS-based risk assessment to
quantify the risk to the receptors and assess the effectiveness of the client ’ s mitigation controls . “ This approach brings together our multidisciplinary services , combining surface water quantity and quality with hydrogeology disciplines and automation to assist with our client with achieving regulatory compliance .”
There is a large increase in water stewardship and operators in the mining sector are recognising that water is both a risk and an asset , and that managing water well is as important as the mine ’ s commodity itself . “ Our experts worked in collaboration with key client stakeholders and held extensive workshops to develop a framework that captured the relevant water quality sources , pathways and receptors . We identified critical water quality indicator parameters and will expand these in future iterations of the project . For each water quality parameter , we defined the risk by applying rules to quantify the influence of the hydrogeology , topography and soil conditions on the final concentration .”
To assess water quality risks , WSP needed to calculate and track water quality concentrations across the entire mine catchment and stream network . To demonstrate regulatory compliance , spatial maps were created showing the existing catchment risk and how these risks could be reduced with proposed mitigation controls .
WSP also developed custom Python scripts to calculate water quality concentrations and risks . “ This approach is highly scalable , and the relevant portions of the scripts can be isolated and improved in future work for this client . This workflow enables collaboration with the client to develop a program for future WSP studies , with outputs to be included in the scripts to improve the catchment risk assessment . By improving and expanding the Python scripts , our client can show regulators that the business is continually increasing the confidence of the results as more information becomes available .”
Moon and Luu state : “ We took the client on a journey and developed a bespoke methodology to the level of detail required for regulatory submission . We used our engineering and science experience to develop a custom framework in lieu of a conventional assessment methodology .”
The scripts enable the client to identify areas of higher risk and quickly analyse options for further works to meet water quality objectives . “ By applying these innovative Future Ready techniques , WSP empowers our mining clients to comprehend the risks involved in their mining operations , make informed decisions , ensure regulatory compliance , and strive towards sustainable water management practices . It ’ s a crucial contribution to continually improve the mining sector ’ s social and environmental performance , and the sustainable management of our shared water resources in an increasingly uncertain climate .”
International Mining | MARCH 2025