• Advances in concrete construction
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• v.1 no.4
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• pp.273-288
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• 2013

The main objective of this research was to evaluate the potentials of self-compacting concrete (SCC) mixes to develop bond strength. The investigated mixes incorporated relatively high contents of dolomite powder replacing Portland cement. Either silica fume or fly ash was used along with the dolomite powder in some mixes. Seven mixes were proportioned and cast without vibration in long beams with 10 mm and 16 mm steel dowels fixed vertically along the flowing path. The beams were then broken into discrete test specimens. A push-put configuration was adopted for conducting the bond test. The variation of the ultimate bond strength along the flowing path for the different mixes was evaluated. The steel-concrete bond adequacy was evaluated based on normalized bond strength. The results showed that the bond strength was reduced due to Portland cement replacement with dolomite powder. The addition of either silica fume or fly ash positively hindered further degradation as the dolomite powder content increased. However, all SCC mixes containing up to 30% dolomite powder still yielded bond strengths that were adequate for design purpose. The test results demonstrated inconsistent normalized bond strength in the case of the larger diameter compared to the smaller one.

• Journal of the Mineralogical Society of Korea
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• v.20 no.2 s.52
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• pp.71-81
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• 2007

The marble-type dolomite from the Jasung Mine, which was farmed by duplicated affects of contact metamorphism and subsequent hydrothermal alteration, corresponds to a high-purity dolomite ranging up to above 98wt.% in dolomite contents. The dolomite contain minor impurities such as quartz, muscovite, and pyrite. It is characteristic that the dolomite is fairy Fe-rich corresponding to 0.4 wt.% due to the presence of pyrite of possible hydrothermal origin. The dolomite is nearly white-colored and constituting with subhedral crystals ranging $0.35{\sim}0.46mm$M in size, forming equigranular texture. Compared to the typical high-Ca limestone from the Pungchon Formation, the powder characteristics of dolomite is rather superior in milling efficiency, yields of fine particles, and size distribution. In addition, except for iron contents, the dolomite powder is no less superior than the limestone in quality and characteristics as fillers with respects to not only whiteness, oil absorption, and specific surface area but also shape characters such as elongation ratio, aspect ratio, and sphericity. This good characteristics of dolomite powder seem to be originated basically from comparatively higher grade and crystallinity of dolomite. Higher iron contents and the presence of sulfides prevents the dolomite from application for uses by thermal treatment, except for metallic manufacture. However, if proper ore separation procedure is available, the dolomite can be sufficiently utilized as substitutes for high-Ca limestone in most fields of filler industries.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.373-378
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• 1999

This study was conducted to investigate the effects of application of the dolomite particles and the shell powder on soil characteristics, dry matter yield and nutritive value of forage in sandy loam soil at the Experimental Field of National Livestock Research Institute, Suweon, from 1994 to 1996. This was compared with control, lime, dolomite 0.5mm, 2.0mm, 4.0mm, and shell powder in mixed pasture. Although there was no significant difference, average dry matter yield for 3 years was increased with the application of lime, dolomite 2.0mm, 0.5mm, control, 4.0mm and shell powder in order. Average crude protein yield of forages was increased with the application of dolomite 2.0mm, 0.5mm, control, lime, shell powder and 4.0mm in order. Lime requirement was slightly increased from 2,410 to 4,853kg per ha with the lapse of time. Although soil hardness was optimum level by second year, it was apt to become hard little by little. Solid phase of soil was lowered with dolomite 0.5mm treatment. The results demonstrated that dolomite and shell powder could be settled a dust problem in farms and a coast pollution as lime substitutes for soil improvement. Therefore, it is desirable for dry matter yield and crude protein yield to applicate the dolomite 2.0mm every 3 years and the shell powder more frequently in sandy loam soil.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.71-78
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• 2011

This paper aims to present the evaluation of engineering characteristics and reusing possibility of waste powders produced in dolomite and limestone nonmetal mining by physical and mechanical experiments on compaction, uniaxial compressive strength, permeability, chemical composition, and so on. Granite soil, 2 types of limestone waste powder, and 1 type of dolomite waste powder were used for main materials, and cement and bentonite were used for admixed materials in this experiments. The findings based on the experimental results are the severe difference of chemical composition of the dolomite & limestone waste powder and the crushed rock waste powder, and the outstanding of engineering characteristics of the dolomite waste powder with high content of MgO compared with the limestone waste powder. The engineering properties on compaction, uniaxial compressive strength, and permeability are enhanced with increase of admixed ratio of waste powder on granite soil. From the experimental results, it can be suggested that the dolomite waste powder admixed with in-situ granite soil is useful as geo-materials with considering of distribution costs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.197-198
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• 2023

This study was conducted as part of research and development of high-strength grout. Accordingly, dolomite aggregate was used as a filler incorporated into the high-strength grout. Dolomite aggregate has a disadvantage of increasing the viscosity of the grout due to higher generation of fine powder than other aggregates. Accordingly, in this experiment, it was confirmed that the viscosity, flow time, and flow of high-strength grout change according to the volume composition ratio of dolomite aggregate and cement-based material. All experiments were conducted based on the Korean Industrial Standard KS F 4044, and the mixing factor was applied according to the composition ratio of the binder and the filler. In the experiment, the amount of fine powder contained in the dolomite aggregate rather than the silica sand used in the past is grasped, and after mixing with the grout accordingly, the mixture is proceeded to measure the viscosity in an unhardened state. In addition, the flow and flow time of the grout are evaluated according to the viscosity. As a result of the experiment, it was confirmed that the viscosity and flow time decreased and the flow increased as the volume composition ratio of the dolomite aggregate to the cement-based material increased.

• Journal of the Korean Ceramic Society
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• v.53 no.1
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• pp.7-12
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• 2016

In this paper, we have developed a simple, new and economical carbonation method to synthesize a pure form of aragonite needles using dolomite raw materials. The obtained aragonite Precipitated Calcium Carbonate (PCC) was characterized by XRD and SEM, for the measurement of morphology, particle size, and aspect ratio (ratio of length to diameter of the particles). The synthesis of aragonite PCC involves two steps. At first, after calcinated dolomite fine powder was dissolved in water for hydration, the hydrated solution was mixed with aqueous solution of magnesium chloride at $80^{\circ}C$, and then $CO_2$ was bubbled into the suspension for 3 h to produce aragonite PCC. Finally, aragonite type precipitated calcium carbonate can be synthesized from natural dolomite via a simple carbonation process, yielding product with average particle size of $30-40{\mu}m$.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.2
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• pp.159-166
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• 1999

This study was conducted to investigate the effects of application of the dolomite particle and the shell powder on soil characteristics, dry matter yield and nutritive value of forages in loam soil at the experimental field of National Livestock Research Institute, Suwon, from 1994 to 1996. Application treatments were control, lime, dolomite 0.5, 2.0, 4.0mm, and shell powder in mixed pasture. Rate of dust occurrence was greatly decreased according to dolomite application and the dissolving rate in soil was highest in shell powder application among treatments. Although there was no significant difference, average dry matter yield of forages for 3 years was slightly increased with the application of lime, shell powder, dolomite 0.5mm, 4.0mm, 2.0mm and control in order. Both Ca and Mg contents of forages were no differences among treatments in 1994. However, all treatments were higher than those of control in 1995. And K and Na contents of forages were no differences among treatments. Lime requirement was greatly increased from 2,630 to 6,150kg per ha with the lapse of time. Although soil hardness was optimum level at first, it was likely to become hard little by little after treatments. Solid phase of soil was lowered a little except for control. Organic matter and available $P_2O_5$ contents of soil were highest in shell powder application among treatments, and K, Ca and Mg contents of soil were no differences among treatments. Ca content was increased a little in 1995, but decreased a little in 1996 compared to that of soil before treatments in 1994. AIso, Mg content was lowered than that of soil before experiment in 1995 and 1996. The results demonstrated that use of dolomite and shell powder as lime substitutes could be reduced dust problem and coast pollution as well as soil improvement. Therefore, it is desirable to apply the dolomite and the shell powder every 3 years in loam soil.

• Journal of the Korean Ceramic Society
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• v.54 no.2
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• pp.108-113
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• 2017

The use of aluminum-based coagulants in water pretreatment is being carefully considered because aluminum exposure is a risk factor for the onset of Alzheimer's disease. Lightly burned-dolomite kiln dust (LB-DKD) was evaluated as an alternative coagulant because it contains high levels of the healthful minerals calcium and magnesium. An organic pore forming agent (OPFA) was incorporated to prepare porous granules after OPFA removal through a thermal decomposition process. A spray drying method was used to produce uniform and reproducible spherical granules with low density, since fine dolomite particles have irregular agglomeration behavior in the hydration reaction. The use of fine dolomite powder and different porosity granules led to a visible color change in raw algae (RA) containing water, from dark green to transparent colorlessness. Also, dolomite powders and granules exhibited a mean removal efficiency of 48.3% in total nitrogen (T-N), a gradual increase in the removal efficiency of total phosphorus (T-P) as granule porosity increased. We demonstrate that porous dolomite granules can improve the settling time and water quality in summer seasons for the emergent treatment of excessive algal blooms in eutrophic water.

• Korean Journal of Remote Sensing
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• v.35 no.6_3
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• pp.1261-1271
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• 2019

In case of Korea, limestone is very useful in various industries. These limestones are mainly produced in Gangwon-do. The study area, which is located in Okgye-myeon, Gangneung-si, Gangwon-do, is Okcheon metamorphic belt where abundant limestone, dolomite stone, and high-grade limestone are produced. The purpose of this study is to distinguish between calcite and dolomite among the limestone which is one of the representative carbonate rocks using the spectral characteristics. For this study,spectral characteristics were measured in the field and laboratory using FieldSpec® 3 spectrometer equipment from Analytical Spectral Device Inc. (ASD). In the field, the reflectance was measured below 50 cm from rock surface, and in the laboratory, the reflectance was measured in the rock surface, the polished surface, and the rock powder. As a result, absorption wavelengths of calcite and dolomite were significantly different around 2,330 nm. In particular, the absorption wavelength band position of dolomite appeared before 2,330 nm wavelength compared to calcite. The study could be used as a basis data for analysis of high-grade calcite limestone.

• Resources Recycling
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• v.30 no.6
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• pp.53-60
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• 2021

In EAF steelmaking industries, MgO content in slag increases due to the addition of dolomite flux to protect refractory lines of furnaces and improve the desulfurization capability of slag. In addition, coal powder is injected in the molten steel bath to increase the energy efficiency of the process. In this regard, the utilization of waste MgO-C refractory material as a flux was examined because it has high amounts of MgO (>70%) and graphite carbon (>10%). A series of experiments were carried out using industrial EAF slag with added light burnt dolomite and waste MgO refractory material from a Korean steel company. The results for the addition of the two fluxes were similar in terms of slag basicity; therefore, it is expected that waste MgO-C refractory material can successfully replace dolomite flux. In addition, when the waste MgO-C refractory material was added as flux, slag foaming phenomenon was demonstrated because of the reaction between the graphite from the refractory material and iron oxides in the slag.