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Study on Pyrometallurgical Processing for Domestic zine ores ( Part 1 )
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| 박평주 , 이재영 P . C . Park , J . Y . Lee |
| KJMM 2(3) 107-112, 1964 |
ABSTRACT
Korean zinc ores are occuring with a large amount of iron content in the form of marmatite (2ZnS·FeS). In order to find out an economical processing of the above ore, characteristics of desulfurization and flotation were tested in this experiment. In roasting, optimum temperature of desulfurization were found 950∼1000℃ and the most favorable condition in the formation of zinc ferrite are obtained above 700℃. Influence of iron content in reduction is also examined.
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Surface Properties of coal in the Aqueous Suspensions ( Report 1) Application to the Recovery of anthracite Slime and Clarification of Mine Water -
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| 최형섭Hyung Sup Choi, 김연식Yeun Shik Kim |
| KJMM 2(3) 113-119, 1964 |
ABSTRACT
Some surface properties of carbon black and anthracite coal were studied by the measurement of electrophoretic mobilities. The electrical charge of carbon particles in the aqueous suspension is strongly influencd by hydrogen ion concentration. The isoelectric point of carbon occurs at pH 3.8. The carbon surface is positively charged at pH values lower than 3.8 and is negatively charged at higher pH values. The experimental results showed that there was no distinctive difference in the interfacial electrical behavior between carbon and anthracite coal in the aqueous suspension. The effect of multivalent ions to the electrokinetic properties of carbon was also studied. In order to recover the anthracite slimes produced in the coal washing and clarify mine water, the proper flocculants and their optimum addition levels were investigated. The above results were correlated with the surface properties obtained.
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Study on the Microstructures and Impact Properties of the Nodular Cast Iron
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| 염영하 Yung Ha Yum |
| KJMM 2(3) 120-135, 1964 |
ABSTRACT
Generally cast iron is so brittle that it does rot serve for the dynamic structures. Nodular cast iron, however, has good ductility, and it is getting more use in dynamic engineering applications. As the conventional notched specimen were inadequate for Charpy and Izod test on cast iron due to their extreme low impact value, the specimen bars used in this experiment were unotched. In order to compare the difference between static and impact properties, tests were carried out in both simple beam and cantilever. Various cast iron were casted and examined, for the microstructures as well as mechanical properties. Impact loads were measured withdy namometer by the electric resistance wire strain gage attached. Through the careful analysis of the data obtained in this experiment, it was concluded that both nodular and malleable cast iron had fairly good adaptability to the dynamic structures.
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