Waste2product Sustainable Mining
Since the beginning, back in 1959, Grecian Magnesite has been following the principle that a deposit is an exhaustible natural resource and therefore the reserves of the mineral deposit should be maximized. Selective mining to maximize short term yield was never an option. On the contrary, the main mine design parameter was always the long-term optimum use of available resources.
In the 60’s when hand-picking was the only viable processing technique for magnesite worldwide, Grecian Magnesite had the providence to stockpile fine Run-of-Mine material extracted daily form the mine, which was not possible to be processed efficiently. This material was stored separately, in order to be used when new processing techniques would have been available. According to the founder of the company, Mr George Portolos, “a mine was exploited and another one was gradually created for the next generation”.
The development of the laser ore sorters in the 70’s allowed the first phase of exploitation of the fine stockpiles. Stockpiling of fine material not possible to treat with the laser sorters continued. The approach of storing material, not possible to treat with currently available techniques, for future exploitation, when technological developments allow it, has become part of Grecian Magnesite’s DNA.
Today stockpiles of fine RoM material of around 60 million tons are available for processing. With the development of new technology optical sorters, its own patended vibrating screen and magnetic separators, and through the use of mobile processing units, exploitation of old fines is an essential part of GM’s production at Yerakini Mine.
Optimum use of resources means that separation efficiency should always be high, and therefore process losses kept to the minimum possible. Through continuous investment Grecian Magnesite is seeking to minimize losses of valuable mineral to the waste streams. In recent years 3 new digital optical sorters replaced older ones, in order to achieve a sharp separation efficiency.
Monitoring of the waste streams at all processing stages, from mining down to calcination and final processing, is a day to day routine. Recycling of material streams and new product development from co-produced materials consumes a substantial part of the R&D effort at Grecian Magnesite. Dust collected from the kiln dedusting equipment is recycled and processed in pelletizers to provide new feed for the kilns. By-products from different processing streams are evaluated and analyzed. According to their chemical and physical characteristics new applications are developed together with the marketing department.
A major project underway, is the exploitation of the dunite material present at Yerakini mine. Dunite is the host rock for magnesite and for decades it was regarded as a waste material. Grecian Magnesite worked on characterization and mapping of the relevant deposits and started exploiting both in-situ material and dunite streams from every-day processing. An array of applications ranging from refractories, metallurgical and construction industries is being addressed. With this project in full development Grecian Magnesite is close to achieving the goal of valorizing >70% of each ton extracted from Yerakini Mine.
