Possibility of reclamation of ash dumps

Abstract

Relevance. The need to dispose ash and slag waste from CHPP-1 and CHPP-2 in Ulan-Ude, which have a negative impact on the environment. A promising way to eliminate environmental damage is the biological reclamation of ash dumps. Its result is manifested in greening dumps and reducing ash deflation. Aim. To study ash and slag wastes from thermal power plants in Ulan-Ude and establish the possibility of reclamation of ash dumps to reduce the negative impact on the environment. Objects. Ash and slag wastes from the ash dumps of CHPP-1 (ASW-1) and CHPP-2 (ASW-2) in Ulan-Ude. Methods. Chemical, X-ray phase, granulometric, microscopic methods of analysis. Results. The authors have determined chemical, mineralogical and grain compositions of ash and slag wastes from thermal power plants. It was established that they have a high content of silicon, aluminum and a low content of calcium and magnesium. Ash and slag contain vitreous, crystalline and organic components. In the waste, to a greater extent, there is a crystalline phase containing silica, mullite, hematite, magnetite and, to a lesser extent, a glass phase, represented mainly by minerals of the orthoclase group. In terms of granulometric composition, the waste from CHPP-1 is dominated by a finer fraction compared to CHPP-2. Laboratory studies of soil mixtures based on ash and slag waste and local ameliorants (sewage sludge, lignin and chicken manure) were carried out. The optimal ratio of soil components was determined, equal to 4:1:1:1. A beneficial effect of sewage sludge was revealed, as well as a negative effect of high doses of bird droppings on growth and development of plants. Pure ash and slag from CHPP-1 and CHPP-2 without introduction of ameliorants can act as an independent substrate for perennial grasses.