Water Treatment Goals
- Treat Acid Mine Drainage (AMD) contaminated water, part of the development of a new zero harm gold resource within an existing polymetallic mine
- Protect surrounding environmentally sensitive alpine area of Tasmania
- Comply with legislative requirements and stringent environmental standards
- Handle issues of site footprint, extreme peak flow events from heavy rainfall, and remote location.
- An assessment of existing technologies indicated these were unlikely to achieve the clients environmental goals
- Ozofractionative Catalysed Reagent Addition (OCRA) process was developed and patented;
- Design, installation and operation of customised plant with mean daily flow rate of 30.5 kL per day.
- Peak flow of over 1.2M litres per day achieved during high rainfall events – the plant remained within discharge limits at all times.
- During test of 10L/s for 2 hours 45 minutes source pH of 6.91, post OCRA recorded at 9.84 without addition of reagent (100kL treated),
- General increase of mean influent of 5.4 to 9.2 (alkaline) with increase in oxidation state of fluid – once introduced to stable precipitant reagent all target contaminant species significantly reduced to less than 5% of influent values,
- Increased oxidation of fluid allows increased reagent reaction efficiency, reducing reagent use by nearly 76%, and
- Many non target species such as oil and grease directly oxidised to less invasive constituent species.
Competitive advantages over traditional AMD treatment methods
- Favorable capital costs,
- Reduced operational footprint,
- Reduced operational costs,
- Lower energy consumption
- Lower reagent consumption
- Increased production rates, varying with contaminant loads
- Treatment solution to a broader spectrum of contaminants (inorganic and organic contamination),
- Ability to control process to meet high standard discharge limits, and
- Greatly reduced post-treatment sludge costs.
Download Acid Mine Drainage Case Study (PDF 502 KB)