Closed loop water circuits for mines | Infrastructure news

The mining sector is estimated to consume around 5% of South Africa’s water resources and many are in drought-stricken regions where water is in short supply.

This calls for the creation of cost effective, water-efficient solution, built around managing the demand for freshwater or alternative water sources and the ability to reduce consumption, limit evaporation, and process existing water in a closed circuit. There also must be a comprehensive understanding of the needs of the mine and effective planning that can accommodate both existing and future needs. 

With a history of over two decades in the mining sector, the SBS Tanks range is ideally suited to the needs of the mining sector and can be utilised at all stages of the process within a closed water circuit.

The first SBS Tanks mining installation took place at a coal mine in Ogies, in the Nkangala District Municipality in Mpumalanga, South Africa. Since that first potable water storage tank installation in 1999, SBS has supplied many liquid storage solutions to mines across South Africa, into Africa and across the globe. The company has worked with many top mining companies to deliver adequate water and wastewater processing and storage systems and has gained vast experience and expertise along the way.

Key considerations

By using this experience, and partnering with mine engineers and procurement specialists, SBS Tanks have established three key considerations to address when developing an effective closed water circuit solution that limits the requirements for ‘new’ freshwater in the mining context.

  • On-site requirements and speed of installation
Historically, concrete structures had been considered the go-to solution for water or liquid storage. However, the mining industry has come to realise that concrete comes with time and cost constraints and can have a greater environmental impact.

SBS tanks can be installed on a simple ring beam structure that can be erected within a few days and  commissioned immediately. Due to their modular nature, SBS tanks can be installed in even the most remote locations and do not require heavy equipment on-site or an access road for components to be transported. 

The local South African SBS manufacturing facility is both ISO 9001 and ISO 45001 compliant, addressing the need for quality, health and safety standards on a mine site. SBS Tanks are also SANS 10160 accredited, with the fire tanks meeting both ASIB and 12th Edition Rules.

Onsite environmental conditions, as well as seismic conditions, need to be established when devising a process water system. Extreme weather conditions such as wind events can impact the solution selection process. Water and liquid storage tanks and reservoirs need to be able to withstand this sort of activity on site. The SBS Tanks Cyclonic Range of tanks is rated for regions with a high incidence of meteorological hazards including tropical storms, hurricanes, and other high-velocity events, designed to withstand winds of up to 240 km/hour.

  • Water supply and requirements
Considerations such as mine water standards need to be factored into the equation too. Does the mine require fresh ‘new’ water or can processed water be used? Will the fresh water come from a municipal source or aquifer, and will it require pre-treatment? If seawater is the most readily available water source, can this be desalinated, and will the system be required to accommodate this process? Are there other requirements such as providing the community nearest the mine, where the bulk of employees will reside, with potable water and will there be access to electricity to pump the water from this tank to the community or will the tank need to be elevated on a hill?

SBS Tanks have been designed and developed for use in used all sectors from mining to manufacturing, bulk municipal supply, rainwater harvesting and water conservation to commercial, industrial and property off-grid resource supply and management. 

As a BBBEE level 2 company, SBS Solutions SA believes in working with communities, the commercial sector, and municipalities to assist with the effective delivery of the mandate of  ‘Water for All’.

  • Space limitations and capacity requirements
SBS products and solutions are adaptable to meet all system and site requirements. Tanks can be built on a limited space, expanding vertically to maximise capacity with 11 or more rings where required. With a range of c 500 sizes and capacities from 7000 litres to 4.4 million litres, SBS Tanks are suited to every stage of the process for liquid, water or effluent storage. This allows for a flexible and adaptable circuit to be designed and even relocated, if necessary, to establish the most effective closed water circuit. 

With a history of servicing the mining sector since 1999, the robust design of SBS tanks can meet demanding conditions on mine sites. Liners or bladders used inside the tank structure can be changed to suit the nature of the liquids stored within. These protect the tank structure from corrosion caused by chemical exposure. SBS Tanks typically have a 65+ year life expectancy depending on conditions onsite, with liners carrying a 10-year conditional warranty.

As a trusted water and liquid storage solutions supplier to the mining industry for over 23 years, SBS Tanks will continue to work hand in hand with mines and mining engineers to offer a range of custom-designed systems to improve water use efficiency and reduce the water requirements of the sector delivering modular and scalable solutions.

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