DESALX®
Membrane-Free Desalination
INDUSTRY
Waste stream treatment at a gold mine processing plant
LOCATION
Victoria, Australia
CAPACITY
2 MLD
COMISSIONED
2019
Summary
Clean TeQ water were engaged to provide a water treatment solution for an existing gold mining operation. The site is located in the state of Victoria, Australia. Clean TeQ was tasked with the design, supply and commissioning of the water treatment plant. The proposed solution was piloted on-site in 2016 using mine water with successful results. A major works agreement for final execution of the project was signed in December 2017.
The system was implemented to treat water and achieve the quality required for aquifer re-injection. This included the treatment of hardness, sulphate, antimony and arsenic. The system needed to be able to perform consistently across variable flowrates (from 20 to 80 m3/h).
The system also acts as a pre-treatment for reverse osmosis to reduce operating expenditures. This is in order to allow a portion of the water to be re-used across the plant as required.
Clean TeQ proposed a combination of technologies to meet the client’s needs. The plant removes both suspended solids (TSS) and dissolved contaminants (TDS: Na, Cl, Ca, Mg, SO4, Metals) from the wastewater, and produces water with a quality suitable for aquifer re-injection, producing a gypsum based brine.
Clean TeQ Water’s unique precipitation process first reduces antimony and arsenic concentrations to very low levels. Hardness and Sulphate is then removed using our DESALX® two-stage continuous ion exchange process. A small volume of sludge containing precipitated arsenic and antimony is produced by the precipitation system, and gypsum-based sludge is produced by the DESALX® system. Water recovery is in excess of 90% and the system is fully automated in order to achieve a consistent water quality across the required range of flowrates.
Water Quality
Species | Unit | Before Precipitation | Before DESALX® | After DESALX® |
Flow rate | (m3/h) | 83.3 | 83 | 71 |
pH | - | 6.8 | 4.5 | 6.0-9.0 |
Total Dissolved Solids | ppm | 7,400 | 7,400 | 5,848 |
Calcium | ppm | 300 | 300 | 85 |
Magnesium | ppm | 321 | 321 | 96 |
Sulphate | ppm | 1515 | 1515 | 700 |
Iron (soluble) | ppm | 1 | 5 | 0.1 |
Total Arsenic (soluble) | ppm | 0.5 | 0.03 | 0.03 |
Antimony (soluble) | ppm | 13 | 0.05 | 0.05 |