• Resources Recycling
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• v.19 no.2
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• pp.54-62
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• 2010

In order to obtain the basic data for recycling of coal mine tailings, the characteristics of coal mine tailings, the formation of AMD from the tailings and the leaching of heavy metal from the tailings were studied. The samples were characterized in terms of chemical composition, mineral composition and content of heavy metal of the tailings were investigated. The effects of time, temperature, content of pyrite, sulfide minerals on the formation of AMD were also investigated. For the leaching tests, the KS method, TCLP method and column test were used. From the investigated data, we can see that the coal mine tailings can be used as aggregate for filling used gallery. We can also see that the formation of AMD from coal mine tailings can be prevented by mixing 4% or more limestone with it.

• Journal of Korea Soil Environment Society
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• v.2 no.2
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• pp.61-72
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• 1997

This research aims to remove the heavy metals, nonbiodegradable COD(NBDCOD), and color using the coal waste. The experimental by heat treatment was performed to advance the adsorption capacity. The results are as follows ; i) The coal waste had the adsorption capacity of heavy metals and the rates were in the range of 20 to 30 percents. ii) The heat treatment was the optimum condition that the reaction time was 6 hours at $500^{\circ}C$, , iii) In the column experimen, non-treated coal waste removed the COD and color in the range of 20 to 60 percents. iv) Heat-treated coal waste showed higher removal rate of the color in biological effluent, and heavy metal and COD removal rates were changed by the filteration rates.

• The Journal of Engineering Geology
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• v.23 no.1
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• pp.19-27
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• 2013

Deformation of a slope at a coal waste depot and the natural slope under the depot was surveyed and investigated at Dogye village in Samcheock city, Gangwon Province. To investigate the behaviors of the slopes, wire sensors and a rain gauge were installed on the crest of the waste depot slope and inclinometers were installed in the natural slope. The results of deformation monitoring at the crest of the waste depot slope using wire sensors revealed increased deformation with increasing cumulative rainfall. The results of monitoring horizontal deformation of the natural slope revealed that maximum horizontal deformation was also affected by cumulative precipitation. However, the groundwater level at the natural slope showed no change with rainfall. These measurements confirm that deformation at coal mine waste depots is closely related to precipitation, indicating that self-loading at such depots increases with rainfall infiltration, thus causing deformation of the waste depot slope. In addition, increasing the self-load of the coal mine waste depot may cause deformation of the underlying natural slope.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.4
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• pp.180-188
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• 2013

The glass of E-glass fiber composition was fabricated by using refused coal ore which is obtained as by-product from Dogye coal mine in Samcheok. We used silica-alumina refused coal ore which has low carbon content relatively, and the amount of refused coal ore has been changed from 0 to 35 % in batch composition. E-glass was fabricated by the melting of mixed batch materials at $1550^{\circ}C$ for 2 hrs with different refused coal ore composition of 0~35 %. We obtained a transparent and clear glass with high visible light transmittance value of 81~84%, thermal expansion coefficient of $5.39{\sim}5.61{\times}10^{-6}/^{\circ}C$ and softening point of $851{\sim}860^{\circ}C$. The glass fiber samples were also obtained through fiberizing equipment at $1150^{\circ}C$, and tested chemical resistance and tensile strength to evaluate the mechanical property as a reinforced glass fiber of composite material. As the result, we identified the properties of E-glass fiber by using refused coal ore are plenty good enough compare to that of normal E-glass without refused coal ore, and confirmed the possibility of refused coal ore as for the raw material of E-glass fiber.

• The Journal of Engineering Geology
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• v.21 no.3
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• pp.199-212
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• 2011

To investigate the causes of ground deformation around the Dogye coal waste depot in Samcheok city, Gangwon Province, we undertook a field survey and performed boring tests and a topographic analysis using maps compiled in various years. The results of boring tests and analyses of ground fractures indicate that the thickness of the soil layer ranges from 9 to 28.5 m and that ground deformation has occurred to the $240{\sim}250^{\circ}$ direction. The topographic analysis revealed that the topography of the site has changed continuously due to the dumping of coal waste. The causes of ground deformation, investigated by both field surveys and the topographic analysis, were the thick layer of soil at this site, the loading weight of coal waste, and the excavation at the lower part of the slope.

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

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1071-1079
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• 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 the Korean Crystal Growth and Crystal Technology
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• v.21 no.6
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• pp.266-273
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• 2011

Foamed glass was fabricated by using glass powder and foaming agents. For the glass powder, we used sodalime glass which's manufactured by using refused coal ore obtained as by-product from Dogye coal mine in Samcheok. And for the foaming agents, we used Calcium carbonate, Calcium phosphate and powder of shale type refused coal ore itself which has high content of carbon materials. We additionally used liquid binder for forming, and mixed together. And we formed rectangular shape and treated $800^{\circ}C$ for 20 min in an electrical furnace. The various kinds of foam glass samples were fabricated according to the kinds of foaming agents. The physical properties of samples, as specific gravity and compressive strength, were measured. Pore structure of each samples were investigated too. Foam glass with specific gravity of 0.4~0.7 and compressive strength of 30~72 kg/$cm^2$. Especially we get satisfying foam glass sample with low specific gravity of 0.47 and high compressive strength of 72 kg/$cm^2$ by the use of liquid calcium phosphate as foaming agent. It also had small and even shape of pore structure. Therefore, it is concluded that refused coal ore can be used for raw materials to manufacture secondary glass products such as a foamed glass panel for construction and industrial materials.

• Resources Recycling
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• v.14 no.4 s.66
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• pp.3-9
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• 2005

In this study, the utilization possibility of coal-preparation refuse emitted from Hwasun coal mine in Korea as a raw material for ceramic body was investigated. The firing shrinkage ratio of ceramic specimen made from the coal-preparation refuse was reduced with increasing the addition amounts of that, while the compressive strength was slightly decreased. The weight of ceramic body was also reduced because carbon contained in the coal-preparation refuse was burn by fring. The water adsorption ratio of the ceramic specimen was under 10 wt%, and the compressive strength of that was over 21 MPa at over $1,150^{\circ}C$ for 2 hr. Therefore, it was possible to make the 1st garde clay brick of KS L 4201 from the coal-preparation refuse.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2005.05a
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• pp.29-30
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• 2005