Question

List some of the common wastes produced in mining operations and mention how these can be reused?

Answer 1

Hint: These are the waste generated during the mining, extraction, and beneficiation of ores and minerals. The mining process results in the production of large quantities of residual wastes which are mostly earth or rock-like in nature.

Correct answer:
The list of some common wastes produced in mining operations are as follows:
-Waste Rock: During the open-pit mining of copper, phosphate, uranium, iron, and taconite a large number of waste rocks are produced. During underground mining a small amount of waste, rock is produced. Waste rock is a combination of coarse, crushed, or rocky material covering a range of sizes, from very large boulders or blocks to fine sand-size particles and dust.
-Mill Tailings: During the grinding, screening, or processing of the raw material extremely fine rejected particles are formed known as mill tailings. It ranges from sand to silt clay in particle size depending on the degree of processing of ore.
-Coal Refuse: During the preparation and washing of coal the coal refuse is produced. It consists of different amounts of slate, shale, sandstone, siltstone, and clay minerals, including some coal that is not separated during processing.
-Wash Slimes: These are produced as waste during the production of phosphate and aluminum. It mainly consists of a large amount of water even after prolonged periods of drying.
-Spent Oil Shale: These are produced after the extraction of oil. When oil shale is vaporized and distilled to produce an organic oil-bearing substance, this black residue is generated.
The reuse of the above-mentioned list of wastes is as follows:
-The mineral processing wastes are mainly used for highway construction purposes. It has been very economical and appropriate to use or reuse of waste products.
-Some mining industries utilize mine waste materials in the construction of dikes, impoundments, and haul roads on the mining property, and in mine rehabilitation.
-Some sources of waste rock or coarse mill tailings may be suitable for use as granular base/subbase, railroad ballast, Portland cement concrete aggregate, asphalt aggregate, flowable fill aggregate or fill, and engineered fill or embankment.
-Fine coal refuse has been recovered for reuse as fuel and is being burned in many cogeneration facilities.
-In the mining area, the soil that is collected from the ground is reused for vegetating areas.
-The rock pieces obtained during the process of mining can be reused for reforming ground and covered with soil for vegetation, construction of dams for absorbing excess water, mixed with cement, and construction material for building purposes.

Note:
-Waste rock, mill tailings, coal refuse, wash slimes and spent oil shale are some common wastes produced in mining operations.
-The best reuse of mill tailings is in local and state highway construction projects.
-Wastewater can be recycled and used for the purpose of irrigation.