Tailings are the materials that are usually left over after the concentration of minerals has been removed. This is at the end of the separation process of the valuable portion of the minerals from the portion that has no economic value. Disposal of tailings actually constitute one of the most significant areas of potential environmental risks that is associated with mining, (Waggit P, 1994).The problem of disposal of tailings into water sources has grown to become a topic of worldwide concern.
Since time immemorial, many mining companies have had the history of disposing off their tailings into rivers. It became a historical pattern that many mining companies used this method for disposing off their tailings. The continuous practice of this has led to very detrimental environmental impacts including radioactive effects such as gamma radiation, pollution of water resources, acidification of water, and threat of contamination of aquatic life.
Usually, the mining process consists of two phases, the mining part and the milling part. The former involves extracting the metal-bearing ore from the rock while the latter component is the process of crushing, grinding and the extraction of the metal concentrate through mechanical and chemical processes. It is through the milling processes that tailings are produced. These tailings need to be placed somewhere close to the mine or otherwise be disposed off. The long used method was the dumping of the material in streams and rivers which gradually resulted in large amounts of sediments accumulating in the river beds thus leading to the contamination and the pollution of the water.
Notably, some modern methods of disposing off tailings to combat the issue were adopted by several mining companies worldwide, and this type of disposal of tailings stopped decades ago. Many companies, for instance, use what is referred to as tailings impoundments. This is discussed in depths later into the paper. Another option that the companies have adopted is the Submarine Tailings Disposal (STD) method which is a way of managing the problem of tailings disposal. It is a safer way of disposing mine waste. However, the problem did not stop completely as some companies still practice it.
The environmental risks associated with disposal of mine tailings in the river are considerable. It smothers habitats, displaces people, diverts water courses and contaminates air, land and water thus greatly affecting the downstream users. The disposal methods of discharging the tailings into the rivers carry the greatest risks for environmental impacts. This is because the eventual spreading of the residue cannot be controlled due to continuous downstream flow of the water. The impacts are hazardous and pose the greatest risk to human, animal and aquatic life.