Intensification of the Ash Impoundment and its Stability Analysis

Abstract

Abstract. The paper presents specific example of method of intensification of ash impoundment. The impoundment for permanent bedding of ashes is situated on the left side of the Danube river. Part of the dam system of impoundment is based upon the original flood bank of Danube river. At the selection of materials for elevation of the impoundment, the decision was made primarily according to two indicators with an economic aspect -the transportation distance and the increase of the accumulation volume of the impoundment. Finally, the decisive criterion was the occurrence of the failure rate of the ash dam systems in comparison with the dams built from loess soils. As the impoundment is situated in the immediate vicinity of the Danube river, safe and failure-free operation has the priority. There is compared the geotechnical characteristics of the loess soils in the original deposition and the loess soils compacted at optimum water content by Proctor Standard compaction test. The proposed method of intensification of ash impoundment is analyzed. The stability analysis provides an example of the utilization of the results of the monitoring of the geotechnical properties of the materials forming the impoundment´s body and the surrounding rock mass. IntroductionThe impoundment for permanent bedding of ashes from the power-producing operations is situated on the left side of the Danube river in the municipality of Štúrovo. The impoundment is partially flown through by surface waters, it is planar, with a circulation system of transport water, with dams on its southern, western and eastern sides. From the north, the impoundment is bounded by a natural slope. The relative position of the impoundment and Danube river is presented in Figure 1 (Google Earth).The original surface of the terrain was at the ground elevation of 104.8 m above the sea level. The dam system of the impoundment consists of the basic dam with its crest at the elevation of 109.2 m altitude and of elevation dams with crests at elevations of 113.5 m and 116.2 m above the sea level, elevated by a method against water and built from local soils, with inclination of downstream slopes of 1:2.5. The lateral section across the dam system of the impoundment is presented in Figure 2. At the southern side, the dam system of the elevation dams is based upon the original flood bank of Danube. In the direction north -south it is divided by a dam into two cassettes. Deposition into the cassette No.1 was finished in the year 1983 at elevation of 120.0 m above the sea level and at present, only the cassette No. 2 is operated occasionally.

Efficiency of biomass and solid waste energy processing based on the cogeneration plant with plasma heat source

“…Plasma gasification is based on a high-temperature process (up to 1100 °C), which allows to get the maximum yield of energy gas, and a further temperature increase (from 1200 °C and above) makes it possible to obtain synthesis gas with a minimum content of tar and harmful impurities. It follows that with increasing temperature, an increase in the percentage of combustible components in the gas, and, accordingly, the calorific value is observed [18][19][20][21][22][23].…”