Mining wastes include waste generated during the extraction, beneficiation, and processing of minerals(Mining Waste | Special Wastes | Wastes | US EPA, n.d.).
Several types of waste are generated in a mine, but three types stand out with the largest volume: waste rock, tailings and mine water(Chapter 4, n.d.).
Let’s explore these types:
- Waste rock
Waste rock is a heterogeneous (coarse materials mixed with fines) material that must be removed to reach the ore. The amount of waste rock that needs to be removed depends on the geometry and location of the ore body, mining method and the composition and stability of the bedrock. Waste rock is often deposited in piles or heaps close to the mine to minimize transports.
- Tailings
Tailings is the residual material from the enrichment process and consist of a fine grained, silty slurry with a high-water content. The amount of tailings generated is dependent on the ore grade, (proportion of valuable minerals in the ore). For example, if the cut-off grade in the ore is 1 % Copper, 99 percent of the total ore would be deposited as tailings.
When tailings are stored under water it is called a subaqueous deposition. The technique helps to minimize the oxidation of mainly sulfide minerals, but also influences the way the tailings settle in the TSF which in turn impacts the long-term stability. Subaerial deposition, deposition above water, is more common than subaqueous.
- Mine water
Water is used in many mining processes. Large volumes of water are used in some processes, i.e. milling. In a mine process, water is a valuable resource, and is often recycled and re-used.
Mining generates significant waste. How can innovation drive better waste management and resource recovery in the industry? Share your ideas!
Reference:
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Chapter 4: Mining waste. (n.d.). Retrieved April 23, 2025, from https://www.sgu.se/en/itp308/knowledge-platform/4-mining-waste/
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Mining Waste | Special Wastes | Wastes | US EPA. (n.d.). Retrieved April 23, 2025, from https://archive.epa.gov/epawaste/nonhaz/industrial/special/web/html/index-5.html
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