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The screen packed fluidized bed roasting of molybdenum trisulfide cake by elutriation which is a by-product at the precipitation of chemical processing plant of tungsten ore at Sangdong, Korea, has been studied. The molybdenum trisulfide was ground, sieved through 65 to 100 mesh screen and roasted at 130 to 500℃ of reaction temperature and constant superficial velocity of 80 cm/sec. It was found that roasting method could be applied 3-multistage reactor. The recommendable temperature ranges of each reactor are 300℃ to 350℃ at the first, 500℃ to 550℃ at the second, and the adequate temperature for dead roasting at the 3rd reactor.

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The tungsten carbide powder was sintered with various metal binders in order to get the necessary information for the manufacture of tungsten carbide tips. The experimental results showed that a good quality of sintered product was obtained when the tungsten carbide powder, mixed with cobalt powder, was pressed at a pressure of 5 ton/㎠ and sintered at 1350℃ for 2 hours. However, the quality of product, using iron or nickel powder as a binder instead of cobalt, was not satisfactory. It is also found that the properties of sintered product, obtained using various binders, seem mainly to result from the characteristics of grain growth caused by $quot;Solution and precipitation$quot; phenomena during sintering.

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This test was made in order to find the feasibility of recovering bismuth from low grade bismuth bearing bulk flotation sulfide concentrate by the chlorination process. Raw material used was obtained from Heungshin mine and assayed 0.93 percent of bismuth and 7.6 percent cf copper. Laboratory tests were made batchwise in a horizontal furnace, using carnallite as chloridizing reagent and charcoal as reductant. Comparative tests using sodium chloride substituted for carnallite showed better result in recovering bismuth. The best result, more than 97 percent of bismuth recovery, was obtained in 4 hours operation at 450 degree centigrade, using 20 percent sodium chloride as chloridizing reagent and 5 percent charcoal as reducing agent.

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This report describes a technical feasibility study of employing the distillation process on producing zinc white from marmatite. The marmatite concentrate was roasted in a 500 gram rotary roaster in order to produce calcine. Distillation tests were made batchwise in a 300 gram Globar furnace at different temperatures ranged 900 to 1200℃, using anthracite as reductant and lime stone as flux. The anthracite and lime stone used in these tests were assayed 57.8% of fixed carbon and 50% of calcium oxide, respectively. Zinc vapor produced in the furnace was immediately oxidized at the vapor outlet, and zinc white fume was simultaneously sent to the bag collector pneumatically. Above results of the tests indicated that (1) anthracite, as reducing agent, can be substituted for coke; d(2) the optimum charge ratio of calcine: anthracite: lime stone was 10:9:1; (3) distillation time was reduced gradually with increasing temperature; and (4) at 1,200℃, commercial grade zinc white was produced with more than 95% recovery for an hour operation.

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This research was undertaken to investigate the effects of particle size of concentrate and amount of binder on the producing physically competent iron ore pellets as blast-furnace feed. Raw material used in this work was obtained from Jaun magnetite iron mine as magnetic concentrate which assays iron content of 57% and particle size distributes 1.58% of minus 325 mesh. Before pelletizing tests were begun, the raw material was reground and magnetically concentrated in order to prepare the sample to various lots. The concentrate was pelletized batchwise in a 16 by 5 inch smooth drum, using bentonite as binder, Results of the research indicated that (1) the particle size distribution of concentrate must consist of more than 60% of minus 325 mesh; (2) variations of bentonite amount in pellets effected considerably higher on the physical strength for green pellets and dry pellet, but less effects were shown for indurated pellets; (3) in these tests, it was found that the optimum consumption of bentonite for this specific sample was at least 3%; (4) compression strength of 5/8-inch indurated pellets ranged up to 100㎏ or more; and (5) comparative tests of up-graded pellets, ranged iron content from 61.2% to 67.7%, showed little, if any, higher values in physical strength.

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Mary materials were surveyed with the hope of finding a material which could be used in room temperature simulations of forming processes on hot steel-Particularly the process of the totary piercing of tubes. By comparing the results of simulations on a model mill with the results of an actual production process, it was found that a composition of 81.0 percent (by weight) Plasticine clay, 16.2 percent kaolin, and 2.8 percent paraffin proved to be an excellent, if not optimum, analog material when used at 55 deg F. As a results of strength data collected in this investigation it is expected that this composition-temperature combination might also be used for the simulation of the plastic deformation of steel at room temperature.

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