Products of solid reactions, which take place between Fe₂O₃ and Mn₃O₄ when the mixtures of the oxides are heated at a high temperature, are ferro-magnetic when quenched from that temperature. The authors studied these reactions systematically by magnetic measurement. According to this study the reactions start at 600°C, and the slow cooling greatly diminishes the ferro-magnetic effect of the reaction products. The variations of the magnetic power of the quenched substances with differences in the composition of the mixtures, heating temperature, duration of the heating and the thoroughness with which the oxides are mixed were carefully studied. It was observed that there is a temperature above which the intensity of magnetization for each mixture ceases to increase as the heating temperature is increased. This temperature is about 900°C for Fe₂O₃·2Mn₃O₄, 1100°C for Fe₂O₃· Mn₃O₄, and 1200°C for 2Fe₂O₃·Mn₃O₄. These results seem to indicate that above such temperatures the reactions between all avaiable oxides are completed. The measurement of Curie points indicated that there areat least four kinds of substances namely, Fe₂O₃·2Mn₃O₄, αFe₂O₃·Mn₃O₄, β Fe₂O₃·Mn₃O₄, and 2Fe₂O₃·Mn₃O₄. The transition from α phase to β phase occurs at 990°C. A reaction diagram was tentatively plotted to explain the solid reaction mechanism.

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The present reports is the result of industrial test for manufacturing special steel, where "gentetu" (raw iron for steel manufacture) was charged about 75% of the total charge into the basic electric arc furnace. When the "gentetu" was used for the charge (73%) into the arc furnace, there occurred about 23KWH 1 ton increase in electric power, and about an hour increase in melting hour. Ore and lime quantities were slightly more increased than in the all return scrap method. The poroduct. revealed no evident effect upon the physical and chemical properties.

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Untersuchungen über die Zähigkeit der Eisenhüttenschlacken von der Rotationsviskosimeter wurden mit Graphittiegel und Graphitumrührer durchgeführt, die im Tammannsche Kohlenwiderstandofen bis 1700°C geheitzt wurde. Die Viskositäat der Dreistoffsystem CaO-SiO₂-CaF₂hatte der Verfasser in der Nähe der CaF₂-Seite an dem Bereich der Basisität gezeigt, und die Einwirkung ihrer Zusammensetzung auf die Entschwefelungskraft wurde ans Licht gekommt. Einige Untersuchung wurde auch an der 8-tonne Schlacken von der basische Betriebselektroofen im Zusammenhang mit der Einflüsse von der Dolomitherde und Magnesiaherde über die Viskosität der Reduktionselektroofenschlacken mitgeteilt.

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In the course of the basic open hearth slag by means of petrographic and analytical research. the existence of the following three stages of slags was observed; (1) the melting-down-stage slag consisting of the CaMn (Mg) SiO₄ matrix and magnetite, (2) the refining slag composed of dical ciumsilicate and the dissolved FeO (more or less containing the undissolved lime and magnesia), (3) the highly basic slag of tricalciumsilicate and dicalciumsilicate matrix. No phenomenal change was observed in the effect of slag-forming materials on the slag composition, excepting the case of, alumina. Some relationship to the slag viscosity and the undissolved materials floating as suspension in the dissolved slag was noticed. In the melting of Cr bearing steel with the basic open hearth furnace, Cr exists as chromite, Fe (CrO)₂, in the slag and equilibrium between bath and slag was expressed by following reaction:
4FeO+2Cr=Fe(CrO₂)₂+3Fe,
and the equilibrium constant covering the range of Cr₂O₃ in slag 0.3-12% was established; that is,
logK=Cr(FeO)₂/(Cr₂O₃)=-41, 500/T+23.1.

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Effect of the temperature of heat treatment on the wire-drawing operation and mechanical properties were examined, in view of obtaining fundamental data on the manufacture of the excellent piano wire. The result of the test on the effect of the copper content in the wire revealed a decrease of the twisting value in case of the copper content more than 0.15%.

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The characteristic of special mild steel sheet for deep-cupping which is suitable for retainers of ball bearing or the other special use was studied. Laboratorial and practical experiments were carried out to manufacture such a high quality iron as the Swedish steel sheet with electric arc furnace using commercial steel scrap.
It was concluded that such sheet almost the same with the Swedish steel in microscopic structure and mechanical properties may be obtained provided that some attention is paied on refining, hot or cold rolling and heat treatment.

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Silicic acid was precipitated as potassium fluosilicate in nitric acid solution and determined by titration with standard sodium hydroxide, after the precipitate was dissolved in hot water.
Iron and steels were dissolved in nitric acid, carbon that separated out oxidised with potassium chlorate and then silicon was precipitated with potassium chloride and hydrofluoric acid as potassium fluosilicate. Basic slag was dissolved in nitric acid directly, while acidic one after fusion with potassium carbonate, and then potassium fluosilicate was precipitated.
The time required for this analysis is about 1725 minutes, so this method is suited for the rapid analysis in steel works.
This method was also applied to the determination of silica in several rocks and fluorspar.

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