Using the method of factor analysis and based on experimental data, several main indexes were selected for calculation of the sulfur retention characteristics of CaCO3 from limestone producing area by linear weighted method. The results provide important reference for coal-fired boilers to select sulfur retention agent.

The design of a new type of cutting-tooth is presented. A layer of high hardness and wear resistance is weld surfaced on the head of cutting-tooth. Results of coal cutting tests show that the lifetime of the new cutting-tooth is about 30%longer.

Using a consortium of bacteria designated Mic-1 or KSARC56, coal is treated aerobically or anaerobically to produce humic acid, volatile fatty acids, lower alcohols, and/or CH4. This process can also be used to convert aromatic compounds, such as phenols and their derivatives, to CH4 and CO2.

The paper describes the principle and method of using dual frequency electrical potential gradient survey instrument to solve the problem of hydraulic connection for water leakage in wells and adits in coal mines from river beds. The method is characterized by strong anti-interference capacity, high resolution ratio, and portability of instrument, and was proved to be effective in practice.

World-wide action for reducing SOx and NOx emissions from coal-fired boilers has resulted from public health and acid rain control considerations. Nowadays, the current global emphasis on environmental protection and pollution abatement is being directed towards the development of several new technologies for NOx and SOx removal, since further reductions in their emissions levels are required in accordance with the latest international directives. The paper presents a DeNOx-DeSOx two-bed combined monolithic reactor for selective catalytic reduction of NOx and catalytic oxidation of SO2 for flue gas treatment.

This system consists of a sedimentation device for treating municipal and industrial wastewater, ore slurries, pulp and paper recausticizing slurries, flue gas scrubbing slurries, and coal refuse slurries. It also has a mixing chamber, a down-flow zone and an up-flowing clarification zone. The input and output of the mixing chamber is controlled so as to require short residence time in the mixing chamber of the influent being treated.

Waste containing organic substances may be combusted or gasified by partial oxidation in the presence of air or oxygen and steam. The gasification process includes the step of adjusting the molar ratio of steam/carbon (H2O/C) for supplied steam and the organic substances containing carbon to a desired ratio. The process continues with partial oxidation at 700° to 900° and discontinuing the steam supply while continuing only air or oxygen supply to combust the remaining combustibles having carbon as their major component.

Most energy systems models treat reductions of technology investment costs exogenously. In these models, investments may be postponed until the costs become low. This model behaviour is unreasonable, since early investments are necessary to realize the cost reductions, a phenomenon known as the experience effect. A global energy systems model with endogenized experience curves has been developed, and a pilot study completed to demonstrate the new insights which can be obtained with the model. In this initial application, the emergence of new energy technologies such as photovoltaics and fuel cells, competition between technologies and technology lock-in effects are studied.

Raw water consumption has been minimized and discharge to nearby rivers reduced at the Sasol Two and Sasol Three coal gasification complexes in Secunda, South Africa, which are designed to recycle many plant wastewaters. The plant has two main water treatment plants: Boiler Feedwater Preparation to serve the utility boilers and utility cooling towers and Water Recovery to treat the coal gasification effluents. Sasol has made many changes to the overall wastewater treatment system, including the elimination of unit processes such as dual-media filtration, carbon absorption, and ion exchange and the addition of evaporators and storage dams. The volumes and chemical composition of the wastewater have changed, and, with them, the operation of the evaporator and other systems. Most recently, Sasol has taken steps to reduce the amount of water accumulating in large ash ponds. As a result of successful testing, a full scale tubular HO system is scheduled to be operational in late 1995.