Mining is one of the main causes of pollution, both through the extraction process but also during the processing of the ores. Waste management presents serious environmental challenges. The sterile that results after the extraction and primary processing of coal is deposited in sterile dumps. When choosing the location of a dump, it is essential to minimise the area that will be occupied by the sterile and to find a location with low economic importance. The sterile is transported by a funicular system – a kind of cable railway which uses small wagons that move up and down a steep slope, balancing each other as one wagon climbs and another one descends. A funicular may be made up of one or more cables suspended on pillars, which carry the wagons loaded with materials over inaccessible mountainous areas.
Sterile dumps are unstable and affect the landscape (being visible from a great distance), morphology and hydrology. Reservoirs have appeared after constructing dumps that barred river courses or allowed rain water to accumulate behind them. The sterile alters the environment, and in the areas where it is deposited, new and underdeveloped environments appear.
Sterile represents the useless part of a mineral deposit or a mining product, which lacks industrial value and is removed at the end of processing.
International standards provide for waste storage in specially prepared dumping sites.
The hazards and problems associated with sterile dumps generated by mining activities include:
· Unstable slopes.
· The formation of acid waters and toxic discharges which contaminate both surface and underground waters downstream.
· Dust pollution and erosion.
· Soil degradation
Tailing ponds, mining sterile dumps, slag dumps and ash pits affect various aspects of the environment:
· Large areas are removed from the agricultural and forestry use.
· The destruction of the soil, vegetation and wildlife of the areas occupied by these structures.
· There is a risk of sliding and instability associated with dumps, which can cause landslides.
· Submerged surfaces are destroyed, and they may include constructions and even architectural works of art.
· Dust and powder cover and smother the vegetation and cause damage due to their chemical composition and the reactions they generate when they come into contact with moisture and the atmosphere; they degrade the natural aspect of an area and soil buildings, having a negative impact on recreation possibilities and tourism.
Because of the great thickness of sterile dumps and accumulated toxins found in the tailing ponds, the occupied areas cannot naturally regenerate and will turn into artificial wastelands.
Mineral residues and toxic substances that leak from these structures find their way into the soil and are neither easily biodegradable with the help of microorganisms, nor are they soluble. Because the soil, unlike water and air, lacks the ability to dispense, its degradation is immediate and irreversible.
Leaks form tailing ponds destroy or at least negatively affect the bacterial flora and fauna of the soil. The sterile that results form processing ores in special plants is transported using hydro-transport methods and is deposited in tailing ponds which perform a mechanical treatment and, for some cases, a chemical treatment.
One of the most controversial projects in Romania is Rosia Montana, where, as a result of the mining activities which will be undertaken, we will be confronted by two types of waste: those generated by gold and silver mining – known as extraction-related waste, and the non extraction-related waste.
Most of the waste resulting from Rosia Montana will be of the extraction-related type, such as quarry sterile and processing sterile.
Quarry sterile is actually quarry rock that does not contain gold or silver that can be economically exploited. At the beginning of the project, quarry sterile will be stored in two dumps, at Cetate (located to the West of the Cetate Quarry) and Carnic (to the South-East of the Carnic Quarry)
Processing sterile is the finely ground material that results after extracting gold or silver from the ore at a processing plant. Before leaving the plant, this sterile will go through an installation to remove toxins, which will decrease the amount of cyanide down to a concentration of 5-7 mg/l, and then it will be stored in a tailing pond located in the Corna Valley.
Sources:
https://www.proenvironment.ro/,
Photography sources:
http://greenly.ro/deseuri/haldele-de-steril-un-pericol-pentru-mediu
Article written by Ionela Marin and translated by Mihail Mitoșeriu
