Utilization Of Coal Combustion By-products Research Articles

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

With a geological reserve of over 170 billion tons, coal is the most abundant energy source in Mongolia with six operating thermal power stations. Moreover, in Ulaanbaatar city over 210000 families live in the Ger district and use over 800000 tons of coal as a fuel. The three thermal power plants in Ulaanbaatar burn about 5 million tons of coal, resulting in more than 500000 tons of coal combustion by-products per year. Globally, the ashes produced by thermal power plants, boilers, and single ovens pose serious environmental problems. The utilization of various types of waste is one of the factors determining the sustainability of cities. Therefore, the processing of wastes for re-use or disposal is a critical topic in waste management and materials research. According to research, the Mongolian capital city's air and soil quality has reached a disastrous level. The main reasons for air pollution in Ulaanbaatar are reported as being coal-fired stoves of the Ger residential district, thermal power stations, small and medium-sized low-pressure furnaces, and motor vehicles. Previously, coal ashes have been used to prepare advanced materials such as glass-ceramics with the hardness of 6.35 GPa, geopolymer concrete with compressive strength of over 30 MPa and zeolite A with a Cr (III) removal capacity of 35.8 mg/g. Here we discuss our latest results on the utilization of fly ash for preparation of a cement stabilized base layer for paved roads, mechanically activated fly ash for use in concrete production, and coal ash from the Ger district for preparation of an adsorbent. An addition of 20% fly ash to 5-8% cement made from a mixture of road base gave a compressive strength of ~ 4MPa, which exceeds the standard. Using coal ashes from Ger district prepared a new type of adsorbent material capable of removing various organic pollutants from tannery water was developed. This ash also showed weak leaching characteristics in water and acidic environment, which opens up an excellent opportunity to utilize.

The application of coal combustion by-products in mine site rehabilitation

Abstract Coal combustion by-products (CCBs) generated from coal-fired power plants have been considered in some circumstances and in some applications as alternatives for natural materials. This review focused on the beneficial use of CCBs for mine sites. The alkaline pH of CCBs has been shown to play a neutralising role for acid mine drainage and the consequent precipitation of metals from solution, mainly as metal hydroxides. Coal combustion by-products have also been used for soil restoration, having been shown to improve one or more of the physical, chemical and biological properties of degraded soils which in turn has led to improvements in revegetation outcomes. In addition, fly ash has been used as a one of the materials in engineered covers that are constructed to encapsulate and isolate potentially hazardous mine wastes. The use of CCBs for mine void backfilling has been considered an opportunity for the bulk utilization of CCBs. Backfilling of underground mine voids with these materials presents the potential to reduce acid mine drainage, limit the risk of land subsidence and minimise and control the likelihood of mine fires. Even though the proactive use of CCBs may eliminate or reduce an environmental burden that remains if separate storage or disposal of these otherwise ‘waste’ materials is required, there may be adverse side effects that could occur through such uses of CCBs, such as the leaching of deleterious elements. Therefore, in the case of their use in mine backfilling, for example, possible environmental impacts need to be assessed and monitored during a testing phase in the context of other variables, and before backfilling with such materials is used on a large-scale. There is still a lack of well-researched information on the practical use of CCBs, and their potential environmental and health effects, and in their use for mine site rehabilitation purposes, effective guidelines and regulations are also limiting factors. In most countries, government regulations regard CCBs as a waste but not a hazardous waste. However, given the high potential CCBs have in a number of roles and functions relating to mine rehabilitation and mine closure, more research at the practical level, and more engagement at a government level, is required.

Coal Combustion Byproducts and Their Usage – Water Field

One of the environmental challenges is a management of solid wastes produced by industrial activities. Among these industrial activities is energy production from power plant, which produces the waste material during the coal combustion processes. The power plant during the coal combustion processes produces the fly ash, bottom ash and boiler slag. These are solid wastes commonly referred to as coal combustion byproducts (CCBs). The coal combustion byproducts are managed in two ways: They may be disposed of in landfills or surface impoundment ponds, or they may be used in some capacity (commonly referred to as “beneficial use”). In this paper an overview of coal combustion byproducts and their physical properties are presented. The benefits of utilizing CCBs in certain application implying the utilization of CCBs in water and wastewater treatment domain are provided here as well. In fact, this paper attempts to encourage and promote the utilization of native coal combustion byproducts where the needs arise. The appropriate studies of native CCBs provide an opportunity to use these materials for supplemental needs in water environment in the future.

Electricity from Coal and Utilization of Coal Combustion By-products

Most electricity in the world is conventionally generated using coal, oil, natural gas, nuclear energy, or hydropower. Due to environmental concerns, there is a growing interest in alternative energy sources for heat and electricity production. The major by-products obtained from coal combustion are fly ash, bottom ash, boiler slag, and flue gas desulfurization (FGD) materials. The solid wastes produced in coal-fired power plants create problems for both power-generating industries and environmentalists. The coal fly ash and bottom ash samples may be used as cementitious materials.

Utilization of coal combustion byproducts in building blocks

Some mechanical and durability properties of composite material produced with by-products of Orhaneli power plant (flue gas desulfurization sludge, fly ash and bottom ash), cement and hydrated lime were investigated. To improve the mechanical properties (compressive and flexural strength) of this material, steam curing was applied and the effect of chemical admixture (high water reducing agent) was investigated. Some physical properties and water resistance of the mixtures were also determined. Furthermore, microstructure of the specimens was investigated using scanning electron microscopy. Finally, to produce construction elements, prototypes of building blocks were manufactured by using some of these mixtures. All kind of power plant wastes (flue gas desulfurization sludge, fly ash, bottom ash) can be utilized with these mixtures, which consist of 90% of coal combustion byproducts. It seems to be a promising material for composite construction elements such as building blocks.

Processing, transporting, and utilizing coal combustion by-products

Processing, transportation, and utilization of coal combustion by-products are presented in three distinct phases. Processing of residues from coal combustion by-products with commercial applications are discussed. The comparison of three transportation systems; trucks, rail cars, and containers; are also presented. The final phase addresses the most recent laboratory and field studies on the utilization of Illinois fluidized bed and pulverized coal combustion by-products for highway materials.

Aims and results of VGB's ERKOM research program for the utilization of coal combustion by-products

Aims and results of VGB's ERKOM research program for the utilization of coal combustion by-products

96/00278 Increased utilization of coal combustion byproducts (CCB) and related benefits on the AEP system

96/00278 Increased utilization of coal combustion byproducts (CCB) and related benefits on the AEP system