Ash Sump

The Podorozhnensky opencast occupies a surface area of 456 ha. It is stretched from the north- west to the south- east for 4 km and is 1.8 km wide, 90 m deep with pit volume about 130 mln m3. The mining workings are environmentally dangerous and can't be left without carrying out a set of liquidation and restoring works.
One of the ways of practical utilization of the Podorozhnensky sulphur opencast can be its filling with ashes from heat-electric generation plants. According to "Lvivteploenergoproekt" information a critical situation with ash disposal developed at the Burshtyn state regional steam electric plant where about 1mln t of ash is made annually. Existing ash dumps have been filled, there is more than 50 mln m3 of ash and no place for constructing some new ones . The ash contains 50 % of silicon oxides, 20% of aluminum oxides, 12 to 20 % of iron. Also present in small quantities are Mn, Ti, Ca, Mg, Na, K, P, S, Cl as well as microelements. The ash is not radioactive. According to the wastes classification it belongs to Class IV , or is not toxic.
As far as the grain -size analysis is concerned the ash mostly consists of dust particles and in dry condition they are easily scattered by wind. Circulating water in ash dumps has high pH value. To prevent migration of that water it is reasonable to seal the ash off by water tight rocks.
The ash can be conveyed to the pit by hydrotransport. But this alternative requires considerable expenditure for constructing ash and circulating water pipelines of nearly 30 km in length. That's why ash transportation by railway is more safe and less capital intensive.
Utilization of the pit offers the opportunity for ash storage without adverse ecological effects and to save hundreds of hectares of land resources