ロータリキルンによるクロム鉱石のアルカリ酸化バイ焼反応の研究

抄録

The reactions between Cr are and Na₂CO₃ during roasting were studied using a rotary kiln (10000mm in length and 700mm in diameter). The followings are results obtained.
Both of the optimum roasting temperature and the optimum basicity of the raw material were quitesimilar to those of the laboratory experiments. The conversion rate of Cr (III) to Cr (VI) was raisedby increasing revolving speed of the kiln. The best conversion of Cr (III) to Cr (VI) was obtained whenthe weight ratio of filler to Cr are being 4 to 1. Considerations on heat balance was made for producingone ton of Na₂Cr₂O₇·2H₂0 by the rotary kiln.
Among the many items of heat output, it was recognized obviously that the loss of heat by radiationand convection from the surface of kiln depended largely upon the capacity.
The following equation represents the relation between the loss of heat per ton of Na₂Cr₂O₇·2H₂0 by radiation or convention and dimensions of kiln.
where E: Loss of heat per ton of Na₂Cr₂O₇·2H₂0 by radiation and convection from the surfaceof a kiln with inner diameter c₂, and outer diameter d₂.
E= {(c₁/ d₁)/(c₂/ d₂)} E0
E₀: Loss of heat per ton of Na₂Cr₂O₇·2H₂0 by radiation and convection from the surfaceof a kiln with inner diameter c₁, and outer diameter d₁.