Saving Money on Mine Water Treatment, Three Case Studies That Provide Valuable Lessons Learnt
Williams, Carl Robert; Bowell, Robert; Wickham, Craig
SRK Consulting (UK) Limited, United Kingdom
As regulations around surface water discharges tighten across the globe there is a growing demand on mining operations to have more and more sophisticated mine water treatment systems. Due to the development of these regulations over time it is perhaps only natural that mines simply upgrade their treatment systems to meet the new criteria instead of looking at other options. Mine water reticulation systems change over time and could be significantly different from the date that the existing water treatment plant was installed, for example, more effective clean – dirty water separation can offer huge CAPEX and OPEX savings.
Inevitably there is a tendency for mining operations to approach vendors directly when they are faced with regulators who are requiring their mines to produce a cleaner discharge. There are some positives to this approach, as vendors have a vested interest in a water treatment plant being constructed the time and effort that they put in to testing and design works is impressive and can sometimes be provided free of charge. However, if the problem has not been adequately assessed the treatment plant may be unfit for purpose, vendors can only work off the information they are supplied. Spikes/variations in chemistry or flowrate must be carefully predicted with adequate factors of safety included.
The other problem that can be faced when defining the issue comes with the treatment process that is selected by the mining company and ultimately the vendor(s) that are then approached to design the plant. Most vendors will not recommend solutions that are not suitable for the specific problem that the mine faces, however they do have a vested interest in selling kit, installing plants, hence will attempt to “make” their product the solution, it could be capable of providing the quality of discharge required but it could not be the most cost effective. Adequately defining the most appropriate treatment method is a quick process for a competent engineer to complete and as is shown in the case studies could save several million dollars in combined CAPEX and OPEX.
It is worth noting that the author of this paper has worked for a supplier of water treatment plants, as an Environmental Manager for a global gold mining company and latterly as a consultant who provides water treatment consultancy services to the mining industry, that hopefully provides this paper with quite a unique insight into this interesting topic.