• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.561-564
• /
• 2005

Gasification has been regarded as a very important technology to decrease environmental pollution and to obtain higher efficiency. The gasification process converts carbon containing feedstock into a synthesis gas, composed primarily of CO and $H_2$. And the synthesis gas can be used as a source for power generation or chemical material production. Through more than nine years, IAE developed and upgraded several gasification/melting pilot plant system, and obtained a good quality synthesis gas. This paper illustrates the gasification characteristics and operation results of two 3 ton/day synthesis gas production facilities. One is entrained-bed slagging type coal gasifier system which is normally operated in the temperature range of $1,400\~1,450^{\circ}C,\;8\~10$ bar pressure. And the other is fixed-bed type gasification/melting furnace system using MSW and industrial wastes as a feedstock.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.6
• /
• pp.1071-1079
• /
• 2011

In this study, coal combustion ash (CCA) was evaluated for its stabilization effect on acidic mine waste with column experiment. Total of six treatments were installed depending on mixing ratio between coal wastes and CCA (0, 20, 40%) and mixing method (completely mixing and layered). Artificial acidic rain (pH 5.6) was used for feeding solution with flow rate of $0.05mL\;min^{-1}$. Result showed that higher pH of leachate was observed as more CCA was mixed. The highest pH in leachate was measured when 40% of CCA was mixed with coal waste (pH of 5.8). Also, complete mixing with CCA and coal waste was more effective to increase the pH of leachate than layered treatment. Regarding the reduction of soluble Fe amount, the highest efficiency (78%) was observed when 20% of coal ash was completely mixed with mine waste. Based on those result, optimum mixing ratio of coal ash with mine waste can be ranged 20-40% depending on environmental circumstances in the field.

• Journal of Powder Materials
• /
• v.13 no.2 s.55
• /
• pp.102-107
• /
• 2006

Recycling industrial wastes such as fly ash from a coal burning heat power plant and shell from an oyster farming were investigated to prevent environment contamination as well as to enhance the value of recycling materials. In this study, the lightweight aggregates and the red bricks were fabricated from fly ashes with other inorganic materials and wastes. The starting materials of the lightweight aggregate were fly ash powder and water glass, and the compacts of these materials were heat treated at $1100^{\circ}C$. The fabricated lightweight aggregates had low bulk density, $0.9-1.2\;g/cm^3$, hence floated on the water and had the strength of 7.0-11.0 MPa and the modulus of 2900-3300 MPa which indicates it has enough strength as the aggregate. Another type of the light weight aggregate was prepared from fly ashes, shell powders and clays. The bulk density, porosity, and compressive strength of these aggregates were $1.19-1.34\;g/cm^3,\;18.3{\sim}56.1%$ and 5-12 MPa, respectively. The addition of a small amount of fly ash powder prevented hydration of the light weight aggregates. The red brick was also fabricated from the fly ash containing materials. It is suitable for the brick facing of a building as it has moderate strength and low water absorption rate.

• Clean Technology
• /
• v.24 no.1
• /
• pp.21-26
• /
• 2018

The coal is a useful industrial resource for a long time. However, coal waste is generated by the mining process. Coal wastes are the main cause of pollution in the surrounding environment, and the amount of coal waste is set at hundreds of millions of tons. Significant amounts of these components in the coal waste are $SiO_2$ and $Al_2O_3$, which is also the main source of zeolites useful in various industries. This study is that the synthesis-zeolite was prepared from coal waste and properties and adsorption performance of synthesis-zeolite were compared with commercial zeolite. The synthesis-zeolite is showed similar properties to the commercial zeolite and also showed excellent adsorption performance against atmospheric pollution induced gases ($CO_2$, Toluene, $SO_2$, etc).

• Resources Recycling
• /
• v.6 no.1
• /
• pp.23-28
• /
• 1997

Iron and slag were prepared by melting mixed industrial wastes in an induction furnace. The wastes were steel can, limestone sludge, waste foundry sand, coal fly ash, and glasses. The effects of their mixing ratio on the charactenstics of the meltcd slag were investigated. The wastes were melted to slag under the constant basicity of 1.2. It was found that the major phases of the slag were P-C,S and C,AS and then ratio was determined by the mixing ratio af waste materials. The recovery of iron was about 93-95%. The feasibility of using the slag as the aggregate was confirmed by thc elution and campression tests.

• Resources Recycling
• /
• v.5 no.1
• /
• pp.3-8
• /
• 1996

CZS(2Ca0 , SiO\ulcorner) phase of cement clinkcr was obtaincd by melting mixcd four indnstrial wasles of limestone sludge, waste Foundry sand, coal lly ash fiorn power plants and chernicas glasses. The effect ot mixing ratio of four rvastc mater~als ou the composnlg phascs in melled slag was investigated. Thc mixed wastes were meltcd to slag by heat under a constant basicity at 1370C. The shg consisted of p -CIS and C,AS(2CaO - A I P , . SiO,). The ratio of two phases was varied with mixing ~atioo f the waste materials. In order Lo increasc the amount ot j -C2S phase, the coal fly ash content should be reduced, while amount of the chemical glass be increased. The coal fly ash contcnt was the most imporlant factor in controlling phases of thc melted-slag.

• Journal of the Korean GEO-environmental Society
• /
• v.6 no.1
• /
• pp.15-21
• /
• 2005

In this study, the utilization of coal-ash and phosphogypsum was considered as the evapotranspiration final landfill cover(ET cover) material. Cover material considered was the mixture of the weathered granite soil, coal-ash and phosphogypsum and so we sequentially performed the leaching test, column test and field model test to investigate the environmental effects of mixtures of coal-ash and phosphogypsum. In the leaching test, all materials had lower heavy metal concentration than the regulated threshold values. The column test and the review of related regulations were carried out to determine the optimum mixing ratio(OMR) and OMR was soil(4):coal-ash(1): phosphogypsum(1) on the volume base, which was applied to field model test. Field model tests were continued from February to June, 2004 in the soil box that was constructed with cement block. It was verified that coal-ash and phospogypsum mixed with soil was safe environmentally and the mixture of both wastes could improve the water retention capacity of cover materials.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10a
• /
• pp.359-362
• /
• 2000

From a practical perspective, sustainable development requires the optimization of current natural resources and the minimization of derived wastes. A major concern with respect to sustainable infrastructure development is the continued depletion of easily-available natural resources and environmental matters are more serious, the concerned about waste materials which are inevitably produced in the manufacturing of the product is getting worse. These wastes must be handled and properly disposed, and many times, although this waste may be environmentally inert, it has been discarded in landfills. But current disposal methods of these by-products create not only a loss of profit for the power industry, but also environmental concerns the breed negative public opinion. therefore, this study evaluates the ECO artificial aggregate and bricks were designed and tested for the end use of fly ash.

• Environmental Engineering Research
• /
• v.10 no.3
• /
• pp.122-130
• /
• 2005

Gasification of carbonaceous wastes such as shredded tire, waste lubricating oil, plastics, and powdered coal initiates a single-stage reforming reactor(reformer) Without catalyst and a syngas burner. Syngas is combusted with $O_2$ gas in the syngas burner to produce $H_2O\;{and}\;CO_2$ gas with exothermic heat. Reaction products are introduced into the reforming reactor, reaction heat from syngas burner elevates the temperature of reactor above $1,200^{\circ}C$, and hydrogen gas fraction reaches 65% of the product gas output. Reactants and heat necessary for the reaction are provided through the syngas burner only. Neither $O_2$ gas nor steam is injected into the reforming reactor. Multiple syngas burners may be connected to the reforming reactor in order to increase the syngas output, and the product syngas is recycled into syngas burner.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.10a
• /
• pp.5-21
• /
• 2005

Urbanization rates of population range from about 1% in the developed countries to about 4% in developing countries. For a global population that may reach 10 billion within the next 40 years, pressure has arisen for an increase in the large-scale use of wastes and byproducts in construction. Ironically, most of the wastes that need to be recycled are generated in large cities where the need for constructed facilities to serve large population is high. Waste and recycled materials (WRM) that are used in construction are required to satisfy material strength, durability and contaminant teachability requirements. These materials exhibit a wide variety of characteristics owing to the diversity of industrial processes through which they are produced. Several laboratory-based investigations have been conducted to assess the pollution potential and load bearing capacity of materials such as petroleum-contaminated soils, coal combustion ash, flue-gas desulphurization gypsum and foundry sand. For full-scale systems, although environmental pollution potential and structural integrity of constructed facilities that incorporate WRM are interrelated, comprehensive schemes have not been developed for integrated assessment of the relevant field-scale performance factors. In this presentation, a framework for such an assessment is proposed and presented in the form of a flowchart. The proposed scheme enables economic, environmental, worker safety and engineering factors to be addressed in a number of sequential steps. Quantitative methods and test protocols that have been developed can be incorporated into the proposed scheme for assessing the feasibility of using WRM as partial or full substitutes for earthen highway materials in the field.