Magnezit Group, Russian leading manufacturer of refractory products, informed of planning to plant a million trees on the industrial waste discharges of one the company’s plants, in Satka (Chelyabinsk Oblast, Russia). If the plan is actually implemented, it will become the most ambitious Russian project ever, aimed at restoration of the land damaged as a result of mining activities. Unfortunately, only few Russian mining companies support the same attitude. There is an enormous amount of waste rock dumps left by the companies after extraction. Neither officials nor business people are interested in doing anything about the open dumps, although development of waste materials could earn them reasonable profits.
Most of the waste in Russia is generated by non-ferrous plants. There is over 200 million tons of mill tailings left from copper-zinc ore processing in the Urals region only. This ore contains approximately 500 thousand tons of copper and 700 thousand tons of zinc, which should be enough to make technogenic deposits development profitable.
It would not be right, however, to claim that none of the companies take responsibility for reclaiming mined land. For instance, the Sredneuralsk Copper Smelter entraps increasingly bigger amounts of slags in ore-dressing due to the scarce supply of raw materials. Polyus Aldan - the oldest Russian gold mining company - adopted the heap-leaching technology in 2017. Having done that, the company started processing vat waste with gold content equalling 0.7 grams per ton, which would have been considered impossible a decade ago.
The economic potential of tailing dumps in Russia is immense. Some experts say there might be up to five thousand tons of pure gold buried inside those dumps. To compare, the global gold production in 2018 amounted to 3,346 tons. Of them, 295 tons were extracted in Russia. If taken into account that one Troy ounce (approx. 31.1 grams) is currently selling for a little less than $1,500 on the open market, we can deduce that over 237,5 billion dollars can be ’extracted’ from waste rock dumps left by Russian gold mining enterprises.
The world’s brightest scientists have been working on finding solutions that could improve profitability of tailing dumps development. Working in this direction has also become one of the priorities for the International Competence Centre for Mining-Engineering Education under the auspices of UNESCO. The Competence Centre based in St. Petersburg is involved, for example, in research focused on increasing efficiency of precious metal and strategic mineral extraction from technogenic deposits.
According to Tatiana Alexandrova, Head of the Department of Mineral Processing at the Mining University, an expert of the UNESCO Centre, ”Electromagnetic and microwave methods of processing industrial waste discharges allow for extracting up to 86-90% of the valuable component, provided its content in the ore is about one gram per ton. I am talking here about gold and platinum group metals, palladium included. Most importantly, one semi-industrial processing cycle lasts 6-8 hours, while heap leaching requires 2-3 months at least”.
Another innovative solution delivered by the Mining University’s researchers is connected with prospects for exploitation of non-commercial apatite-nepheline ore deposits, usually limited in volumes of the valuable component. This research is of particular importance as it also gives an opportunity to simultaneously extract rare earth metals, so needed for manufacturing missile parts, airplanes, and other high – tech products.
Nadezhda Nikolaeva, Senior Lecturer of the Department of Mineral Processing, noted "The core of our development lies in the new combination of flotation agents, that are used in particular for grinding. The new alteration allows to start using lower-graded ores in manufacturing - ores with a valuable component of 5 to 8%, whereas now the value equal to 18% is considered profitable. Extraction of rare earth metals occurs at an intermediate stage prior to flotation, during mechanochemical activation".
Both projects were officially presented in Helsinki at the forum dedicated to refining waste conversion techniques and improving profitability of technogenic and low-grade ore deposits development. The Expert Forum was organised in November by Lappeenranta-Lahti University of Technology (LUT University), the European Institute of Innovation and Technology, and the International Competence Centre for Mining-Engineering Education under the auspices of UNESCO.
According to participants of the Forum, mining businesses nowadays also have to work on shaping a positive image of the industry in general. They need to inform people of inextricable link between the quality of life and mineral extraction, as the latter is the first link in the supply chain of almost each product, starting from mobile phones and ending with electric cars. Of course, positive agenda also requires reducing the ecological impact and making reclamation plans at the very initial stages, when exploration and surveying work is still in progress.
