Benefits from coal cleaning

Home : Services : Borovac process : Benefits

The existing massive coal excavation practice will remain unchanged for both simple and complex coal seams.

Bulk miming of good quality coal (GQC) from simple seams will continue and it will be dispatched to crushing, milling and power plants.

Low quality coal (LQC) from complex seams that include interlayers of waste, will also continue to be excavated on massive scale (bulk mining). However, it will be treated by the Borovac process before being dispatched to power plants for combustion.

Implementation of the Borovac process will increase recovery of overall confirmed coal reserves from the deposits. It is also likely to enable consumption of the coal sections that are currently considered to be out-of-balance reserves.

LQC treated by Borovac process will be supplied to power plants with a high quality that allows full utilization of existing installed capacities at power plants.

Removal of waste from ROM coal will consequently result in reduced inlet ash concentrations at filter inlet (i.e. ESP's). This will increase ESP's removal efficiency and reduce overall particulate emissions into environment.

Removal of the abrasive silicate sand from the ROM coal will reduce maintenance requirements on ESP's as well.

Removal of portion of sulphur together with coal cleaning waste will reduce SO2 stack emissions.

Crude oil has frequently been used in winter periods to support the fire in plant boilers due to very low quality of supplied coal. This crude oil with very high sulphur content has resulted in excessive air pollution. Implementation of the Borovac process may eliminate the need for fire support with crude oil in all plants.

Besides having the sand and clay as waste matter in ROM coal, some coals contain limestone impurities that cannot be removed by Borovac process. However, their presence in the combustion process and increased Ca/S stechiometric ratio contribute to reduction of the sulphuric gas emission.

The technology for building the ridged embankments on waste-ash disposals sites by two-stage cycloning forms an integral part of the Borovac process. This technology has already been successfully implemented on a full industrial scale at numerous power plants in Europe. In addition to commercial benefits, the technology provides improved stability of the large waste-ash disposals. The ridged disposal embankments built by this method are of uniform quality along the whole perimeter, thus enabling building of very high embankments.

Combined disposal of ash with coal cleaning waste (tailings) is also preferred, regardless whether the ash is disposed outside or inside the pit excavated area. The outer exposed surfaces of the disposal embankments as well as final surfaces after mine plant closure will be protected with cover of clayish tailings from the cleaning process. This will enhance the revegetation works.