Zinc-Ferriteに関する研究 (第3報)
酸溶速度におよぼす生成温度の影響
1964 年 80 巻 910 号 p. 362-365
詳細
1964 年 80 巻 910 号 p. 362-365
The effects of decomposition temperature of ferrous oxalate and of formation temperature of zinc-ferrite on the rate of dissolution in dilute sulfuric acid were investigated.
Six species of zinc-ferrite were formed at 900 and 1, 190°C from the stoichiometric mixtures of ferric oxide, which was prepared by thermal decomposition of ferrous oxalate at 500, 700 and 900°C, and zinc oxide.
From the previous result that the rate of dissolution is approximately proportional to the surface area, pparent rate constant K (dependent on surface area) and rate constant κ(independent of surface area) of each specimen can be calculated.
Apparent rate constant K of zinc-ferrite, which was formed at 900°C, varies with the decomposition temperature of ferrous oxalate, but rate constant κ remains constant. This means that the difference of K arises mainly from surface area of zinc-ferrite, and that decomposition temperature of ferrous oxalate has no influence on the property of zinc-ferrite.
The zinc-ferrite, which was formed at 1, 190°C, dissloves with the rate lower than that of zinc-ferrite formed at 900°C. But, when κ were compared, k of zinc-ferrite formed at 1, 190°C are higher than those of zinc-ferrite formed at 900°C, except when the ferric oxide prepared at 500°C was used. This means that, considering the rate of dissolution per unit area, the zinc-ferrites, which were formed at 1, 190°C, dissolve more easily than those formed at 900°C.
