Desulfurizing experiments were conducted at 1473 K for a molten Cu-8%Sn-0.1%P alloy by using a Na₂CO₃ flux in low freqency melting furnaces. Desulfurization and dephosphorization began simultaneously. Desulfurization ceased earlier than dephosphorization and then the reversion of sulfur was found proceed. The use of carbon crucible promoted desulfurization and suppressed the reversion of sulfur more strongly compared with the use of an alumina crucible. Sulfur distribution between the melt and the flux was found to be determined by two major factors. One is the basicity of the flux, being affected by P₂O₅ content in the flux. The other is the partial pressure of oxygen at the interface between the melt and the flux, being affected by furnace materials, covering materials and Cu₂O content in the flux. The desulfurization rate was explained quantitatively by a double interface model assuming mass transfer coefficient in the melt as 1.82 g·cm⁻²· s⁻¹ and that in the flux as 0.063 g·cm⁻²· s⁻¹. Dephosphorization and the influence of Cu₂O content in the flux were also investigated.

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(1) We tested the influences of sodium chloride of varying concentrations on the heading and riping of rice plant. (2) With high concentrations of NaCl solutions supplied, the growth and tillerings were retarded. (3) Contents of Cl in leaves and stems increased, and chlorophyll contents decreased with high concentrations of NaCl solutions supplied.

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Hot metal refining using the flux containing Na₂CO₃ was studied on a laboratory scale by comparison of bottom injection method with top blowing method using argon or oxygen gas as a flux carrier.
Excellent desulfurization performance could be obtained by the bottom injection method, particularly on using argon gas as a flux carrier. This was due to a increase in flux/metal interfacial reaction area which was estimated about 3 times as large as that of top blowing method. However, efficient phosphorous removal could not be achieved by the bottom injection method because the reaction of Na₂CO₃ with C took place instead of the reaction of Na₂CO₃ with P, especially in the region of low phosphorous content level. On the other hand, in the case of top blowing, dephosphorization reaction proceeded to the extreamly low phosphorous content level without remarkable decarburization reaction.

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Thermal-shock resistance and response performance of solid electrolytes for an oxygen probe applied in steelmaking processes were studied. One-end closed tubes of ZrO₂-8.1 mol% MgO with various volume fraction of cubic phase (V_c) were used for measuring oxygen activity in a production line, and changes of phase composition in ZrO₂ during immersion into molten steel were investigated. Good thermal-shock resistance was realized by decrease in the cubic phase whereas good response performance was obtained by increase in the cubic phase. For the ZrO₂-8.1 mol% MgO, an optimum fraction of cubic phase was 27%. The relationship between reliability of measured oxygen activity and the phase composition was also discussed.

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VAD (Vacuum Arc Degassing) plant is characterized by 3-phase AC are heating under reduced pressure while Ar gas is injucted by a porous plug set at the bottom of ladle. Thus alloying, desulphurizing, oxygen reduction and dehydrogenation can be made easily and sufficiently. For instance, the sulphur concentration can be easily achieved to less than 0.005%, the oxygen level of the slab of low alloy steels ranges between 10 and 35 ppm, and, the hydrogen in the molten steel after degassing is 1.5 ppm on an average.
At Kure Works, high grade carbon steels and low alloy steels, such as structural steels, tool steels and bearing steels, and extra low carbon steels (carbon concentration is less than 0.005%) are produced economically by this plant from the molten steel of LD converters. This paper describes the techniques procedure for manufacturing these steels by this LD-VAD process.

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Removals of silicon and phosphorus from hot metal with lime based flux simultaneously have been studied in the experiment of 100 kg scale.
Results obtained in this work are as follow:(1) Silicon content of hot metal at which simultaneous removal of silicon and phosphorus can proceed increases with an increase of feeding rate of oxygen. (2) When oxygen feeding rate is more than 0.88 Nm³/min·t, dephosphorization can proceed even if with low basicity slag like CaO/SiO₂ of 2. (3) To proceed simultaneous removal of silicon and phosphorus effectively, it is very important to keep high values of oxygen feeding rate and oxygen potential at slag-metal interface.
Oxygen feeding to top slag is specially effective for increasing an oxygen potential of slag-metal interface.

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上田秋成が、死去後の遺品の処分を託した松本柳斎は、元々小澤蘆庵に和歌や国学を学び、蘆庵没後は秋成を師とした人物である。柳斎は、秋成の書簡集である『文反古』を編集・出版しているが、そこには柳斎と秋成の往復書簡も収録されている。その往復書簡の原型が書き留めらた『雪乃不流道・心能友』は、文化元年(一八〇四)から翌年にかけて柳斎が讃岐に帰郷した折の和歌紀行だが、その紀行文には、秋成から信頼されていた柳斎の、篤実なひととなりが如実にあらわれている。

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A new process for the hot metal dephosphorization is examined. It is done in the 200 t hot metal ladle, soda ash being top charged, oxygen gas being top blown and nitrogen gas being injected through a submerged lance. Dephosphorization reaction is analyzed in terms of its reaction equilibrium and stirring intensity or energy involved.
Equation for the dephosphorization equilibrium is established by the extrapolation of the laboratory data at 1 600°C :
logK=(P₂O₅)/[P]²=1873/T[9.49+8.41log{(CaO)+2.32(Na₂O)} - 4.78log(SiO₂)] + 5loga_o+0.26[C] +
36 850/T-25.32
This equation is found to well describe the hot metal dephosphorization all through the treatment. Thus, the reaction is found to proceed very close to the equilibrium.
The effect of the oxygen blow and the stirring upon the dephosphorization is clearly demonstrated. The optimum stirring energy is found to exist for the maximum dephosphorization attainment: between 0.6 to 1.5 MJ/t.

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The effect of the temperature, silicon and manganese in carbon-saturated iron (0.1% P, 0.05% S) on the dephosphorization and the desulfurization was studied by the use of the 2Na₂CO₃-Na₂SO₄ flux. The degree of the dephosphorization and the desulfurization considerably decreased and the evaporation of sodium increased with increasing temperature. As a result of the flux consumption for the oxidation of silicon, their degree was found to remarkably decrease, but manganese in metal was found to gradually decrease. The reversion of phosphorus and sulfur was observed after the end of the flux addition, but the extent of their reversion decreased when silica was present in the flux.
The behavior of the dephosphorization and the desulfurization obtained by the 2Na₂CO₃·Na₂SO₄ flux was compared with those by the Na₂CO₃ flux and the 2Na₂CO₃·Fe₂O₃ flux. The degree of the dephosphorization was almost same, but the remarkable evaporation of phosphorus was observed according to the acceleration of CO formation by the reduction of iron oxide with carbon in metal. This evaporation was also observed in the 2Na₂CO₃·Na₂SO₄ flux, but its extent decreased with increasing the P₂O₅ and the SiO₂ concentration in slag.

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In order to get a basic knowledge concerning dephosphorization of hot metal by soda ash, the behavior of phosphorus and carbon in metal and gases evolved during the reaction was examined.
Sodium carbonate explosively reacted with liquid iron containing 3 5% carbon. Gaseous material evolved by the reaction was only carbon monoxide.
When sodium carbonate was added to liquid 4%carbon-0.2%phosphorus-iron, dephosphorizing reaction rapidly occurred within the first few minutes. While, decarburizing reaction began at around the period when dephosphorization was almost completed. Only a small amount of carbon dioxide gas evolved early in the experiment, gaseous material evolved over a run was mainly carbon monoxide.
It was presumed from the relation between the amounts of carbon monoxide gas evolved and phosphrus removed that the dephosphorizing reaction of high carbon iron melt can be expressed as follows ;
5Na₂CO₃ + 2P = 5Na₂O + P₂O₅ + 5CO
The reactions ofdephosphorization and decarburization were retarded by the addition of sodium disilicate together with sodium carbonate.
It was found that the phosphate capacity of high sodium carbonate flux was very low compared with those of Na₂O- SiO₂ fluxes.

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