• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.207-211
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• 2007

It is a quite quality concerning to control the temperature of single crystalline growth as it does when we get most of heat treating products. It is also important factor to control the temperature when we make the $Al_2O_3$(single crystalline) used to artificial jewels, glass of watches, and heat resistant transparent glasses. Thus, it is a major interest to get the proper temperature in accordance with the time process while we are making mixture of oxygen and hydrogen to have the right temperature. In this paper, we will study of electrical valve positioning system with DC-Motor for the gas mixture to improve the quality of products.

• Korean Journal of Materials Research
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• v.27 no.5
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• pp.281-288
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• 2017

In this study, Fe-Ni slag, converter slag and dephosphorization slag generated from the steel industry, and fly ash or bottom ash from a power plant, were mixed at an appropriate mixing ratio and melted in a melting furnace in a mass-production process for glass ceramics. Then, glass-ceramic products, having a basalt composition with $SiO_2$, $Al_2O_3$, CaO, MgO, and $Fe_2O_3$ components, were fabricated through casting and heat treatment process. Comparison was made of the samples before and after the modification of the process conditions. Glass-ceramic samples before and after the process modification were similar in chemical composition, but $Al_2O_3$ and $Na_2O$ contents were slightly higher in the samples before the modification. Before and after the process modification, it was confirmed that the sample had a melting temperature below $1250^{\circ}C$, and that pyroxene and diopside are the primary phases of the product. The crystallization temperature in the sample after modification was found to be higher than that in the sample before modification. The activation energy for crystallization was evaluated and found to be 467 kJ/mol for the sample before the process modification, and 337 kJ/mol for the sample after the process modification. The degree of crystallinity was evaluated and found to be 82 % before the process change and 87 % after the process change. Mechanical properties such as compressive strength and bending strength were evaluated and found to be excellent for the sample after process modification. In conclusion, the samples after the process modification were evaluated and found to have superior characteristics compared to those before the modification.

• Resources Recycling
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• v.7 no.2
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• pp.39-45
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• 1998

We smelted thc pellets made by mixing the distilled carbon from wlISte Lires, LD converter dust and slag with reduction process in the revcrberatory furnace. Thc obtained results are as follows 1) The removal mte of zinc appears above 97% after T reducing the pellets at $1300^{\circ}C$ for Ihr and the zinc content in the residue are 0.1~D.2%. 2) Under the mixing condition of 500 g LD dust. 150-200 g LD slag and 30-50 g distilled carbon of waste lires the removal raho of zinc shows above 95%, while t the 50-60% Fe remains in the residue. 3) After smelting at $1350^{\circ}C$ for 3hrs, the recovery ratio of pig iron reduced from lhe p pellets containing 15-20% LD slag and 4.1-7.2% distilled carbon of waste tires appears in the range of 89.3-92%. 4) Tbe c chemical composition of the recovered pig iron is 1.7%C, O.05%P, 0.05%S and balance Fe. 5) Tbe recovered dust from the d dust collcctor alter finishing the reduction rcaction appears as a crude zinc oxide conLaining 60% zinc.

• Resources Recycling
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• v.21 no.3
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• pp.21-27
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• 2012

In order to make high-purity ferro-manganese from $Mn_3O_4$ dust, the application of aluminothermy process to the reduction of $Mn_3O_4$ dust was investigated in previous work. The result showed the fact that can be obtained high purity ferro-manganese which have over about 93% of manganese content and lower impurities such as C, P, S than those of KS D3712 specification. The addition of silicon powder instead of aluminum powder was investigated as reductant in the thermite reaction process of $Mn_3O_4$ dust in this work because its production cost is lower than that of aluminum powder. In case of addition of silicon powder only as reductant, the experimental result showed the unstable ignition and no thermite reaction of mixture, but in case of simultaneous addition of silicon and aluminum powders as reductant, showed the fact that can be obtained high purity ferro-manganese which have much low content of impurities such as C, P, S component.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.4
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• pp.391-399
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• 2005

This paper deals with the survey of domestic hydrogen production, consumption, and distribution. The amount of domestic hydrogen production and consumption has not been identified, and we survey the amount of domestic hydrogen production and consumption by industries. The hydrogen production industries are classified into the oil industry, the petrochemical industry, the chemical industry, and the other industry. In 2004, the amount of domestic hydrogen production was 972,601 ton, which corresponded to 1.9% of the global hydrogen production. The oil industry produced 635,683 ton(65.4%), the petrochemical industry produced 241,970 ton(24.9%), the chemical industry produced 66,250 ton(6.8%), the other industry produced 28,698 ton(2.9%). The hydrogen consumptions of corresponding industries were close to the hydrogen productions of industries except that of the other industry. Most hydrogen was used as non-energy for raw materials and hydrogen additions to the process. Only 122,743 ton(12.6%) of domestic hydrogen was used as energy for heating boilers. In 2004, 47,948 ton of domestic hydrogen was distributed. The market shares of pipeline, tube trailers and cylinders were 84.4% and 15.6%, respectively. The purity of 31,848 ton(66.4%) of the distributed hydrogen was 99.99%, and 16,100 ton(33.6%) was greater than or equal to 99.999%. Besides domestic hydrogen, we also identify the byproduct gases which contain hydrogen. The iron industry produces COG( coke oven gas), BFG(blast furnace gas), and LDG(Lintz Donawitz converter gas) that contain hydrogen. In 2004, byproduct gases of the iron industry contained 355,000 ton of hydrogen.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.1-8
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• 2023

In this study, to reduce CO₂ emission in the cement manufacturing process, we evaluated the limestone that is used as a raw material for cement, substituted with steel slag by the various substituted levels. Based on the chemical composition of each raw materials including limestone, and blast furnace slow cooling slag, converter slag, and KR slag as an alternative raw material, we simulated the optimal cement raw mixture by the substitution levels of limestone. Test results indicated that the steel slags contain a certain level of CaO that can be used as alternative decarbonated raw materials, and it has enough to partially reduce the amount of limestonem. And we estimated the maximum usable levels of each raw material. In particular, it was confirmed that by using a mixture of these raw materials rather than using them one by one, the effect of reducing limestone was increased and CO₂ emission from the cement manufacturing process could be reduced.

• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.89-99
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• 1998

Sorption of the aqueous cyanide onto steel mill sludge and steel mill slag, both of which are the by-products from the converter furnace, was studied. In the study, the influence of temperature, activation energy, concentration and pH on sorption of cyanide was investigated. Three different temperature($25^{\circ}C$ > $37^{\circ}C$> $50^{\circ}C$) was chosen to represent that of landfill leachate. Initial concentration was 1 mg/$\ell$ 5 mg/$\ell$, 10 mg/$\ell$, and 20 mg/$\ell$. In addition, pH was set to three different level, that is, 3, 7, and 11 respectively. As the result of batch mode experiment for cyanide adsorption, the removal rate was found to be proportional to the initial concentration of cyanide. The order of removal rate was 20 mg/$\ell$> 10 mg/$\ell$> 5 mg/$\ell$> 1 mg/$\ell$. Similarly the influence of pH was proportional because of the change in solubility of cyanide. The order of removal rate was pH 11 > pH 7 > pH 3. As the temperature increased, so did the removal rate. The reaction was endothermic and the value of activation energy(Ea) was 127.93 J/mole and 59.44 J/mole respectively at 1 mg/ιand 20 mg/ιof initial concentration. From the experiment, it can be postulated that the capability of steel mill by-products to attenuate aqueous cyanide is enough to be used as substitute for clay liner of landfill site in the aspect of pollutant removal.