Mining waste comprises different types of rock, overburden, slurry and tailings from the processes of excavation and dressing.

Further physical and chemical processing of a wide range of materials create additional waste from mining operations. Therefore, mine wastewater treatment is required, in order to avoid the contamination of the surrounding environment.

This guide aims to explain innovative approaches of sustainable wastewater treatment in the mining industry.

In this overall guide to mining wastewater treatment you will learn:

• Why is it necessary

• Necessary condition of treatment

• Typical treatment steps

• Water treatment techniques for Mining Wastewater Treatment

Why Is Mining Wastewater Treatment Necessary?

Mining wastewater is originated from those mines where underground mining or open pit mining is performed. The mine water is collected and stored in above ground dams or underground caverns. Therefore, there is a necessity of mining wastewater treatment to ensure a pollution free environment.

Over the years, mining companies continue to occupy and mine remote locations. Because of this, the intensity and level of heavy metal contaminated wastewater is increasing gradually.

The mounting levels of wastewater discharged from the mining sector is playing a pivotal role in environmental pollution. Hence it has become a key concern for global ecologists studying this issue.

Necessary Conditions of Mining Wastewater Treatment:

• There are a lot of needs to ensure mining wastewater treatment from the quantity and quality perspective.

• The amount of mining entirely depends upon the ground conditions and the level of the underground water table. The quality of the mine water depends upon different local conditions.

• A lot of water management strategies are used to ensure the environmental consequence which focuses on the modern mining operation aspects.

• Mining companies should develop water management plans to control the capacity of water contamination to prevent letting polluted water to be discharge into the environment.

• Proper measures should be taken by global mining companies to ensure the treatment of contaminated mine water. Mining companies are expected to reduce the amount of wastewater to the environment in a sustainable way.

• New concepts are being introduced in many countries for mining wastewater treatment. These new concepts called Cleaner Production (CP), or No Waste Technology (LNWT) were developed in efforts to control the current issue of water contamination in this industry.

• There are various treatment innovations for mining wastewater treatment. It is a necessity to clean the contaminated water. The treatment of this contaminated water can be either active or passive or a combination of both.

• In active mine treatment, innovative software can potentially calculate the effluent chemistry of the mine waster to accurately predict appropriate treatment methodology. Since, mine effluent is typically acidic, pH adjustment is typically required to raise the pH. This allows for effective heavy metals and certain dissolved organics removal via advanced electrocoagulation followed by clarification in sedimentation ponds for removal. For high quality tertiary effluent, membrane filtration such as ultrafiltration or reverse osmosis and specialized ion exchange systems are typically used to allow for potential reuse.

• In passive mine treatment, this process often relies on the use of wetlands along with water monitoring to foster the growth of natural bacteria for contaminant reduction. This passive treatment approach is lower cost, but does not respond as well to the acidic pH of mine water. This approach typically includes filtration and absorption through plants and soils.

• Both treatment methods typically require maintenance.

• Natural phenomenon such as rain, snow melt, and water streams should be diverted from entering mine sites. These natural phenomena create the conditions required for acid mine drainage, when water comes into contact with the exposed mined rock surfaces.

How Mining Wastewater Treatment Operates:

• In the first step, mine water is captured appropriately to avoid further contamination/leaching of the exposed mined rock in open pit or underground mining operations. This can require the construction of upstream dams which lessen the possibility for water intrusion into these mining locations.

• In the second step, the mining wastewater is treated/recycled and released from the mining areas, minimizing environmental impact on surrounding ecosystems and water bodies surrounding the mining locations.

• The operation would also limit the drainage water to dissolve/leach the rocks in these mining areas by redirecting water streams through other channels by using pipes and liners as required.

• After treating/reusing the mining wastewater, this treated water can be used for non potable process applications.

Water Control Techniques of Mining Wastewater Treatment:

Mining wastewater treatment systems carefully handle contaminated mine wastewater. This enables the discharge of treated water into the ecology and other water sources minimizing any contamination. It may also allow the ability to recycle/reuse to minimize mine operation costs.

Mine wastewater treatment systems, utilize multiple techniques to reduce water contamination.

• The first method of mining wastewater treatment is interrupting and diverting the water of rain, streams, and river from flowing towards the mining area as mentioned above. This can be accomplished via robust and upstream dams that are built up which reduce the potential for water contamination at these locations.

• In the second method, the suspended solids are removed prior to further water treatment to achieve higher quality water for reuse or other non-potable applications.

• Additionally, sedimentation ponds are designated to allow the pH adjusted wastewater to be clarified with clarified water pumped for further treatment. The stabilized solids would be separated on the bottom of the ponds.

• Additionally, the collection of the drainage water discharged from the rainfall at the mine site by using liners and pipes would be used. This is followed by the step of redirecting the water to dams to avoid water leaching and associated contamination.

• Lastly, installation of solid lines, channels, and covers on mined rock and ore piles are also followed. This is in order to decrease the possibility of water contact to leach/precipitate metals in the rocks causing contamination for groundwater or surface water sources.

Genesis Water Technologies has the expertise to engineer and supply specific process water and wastewater solutions for mining companies.

Does your mining company have issues with water scarcity? Contact Genesis Water Technologies, Inc. via our regional offices worldwide or you can reach us via email at customersupport@genesiswatertech.com for a no cost initial review of your application.