铁酸盐形成中钴的行为与控制

研究了硫酸亚铁溶液经空气氧化水解生成铁酸盐的过程，以及此过程中钴的行为与控制。所获得的产物经X射线衍射分析与红外光谱测定表明，在pH=11下部分氧化的亚铁溶液沉淀出绿锈中间产物并吸收溶液中的钴离子，绿锈中的亚铁继续氧化、水解、脱水，可获得尖晶石型钴铁酸盐CoxFe3-xO4。随着初始溶液中铁钴配比R从27降低到3，x的取值由0．13增大到0．45，但进入铁酸盐的钴的比例(沉淀率)则有近100％降至近53％。温度的升高不利于钴取代铁酸盐中的铁。

Behavior of Cobalt and Its Control in Formation of Co-Ferrite

The behavior and control of cobalt in formation of Co-ferrite by oxidation-hydrolysis of aqueous ferrous solution were investigated. The XRD patterns and IR spectra of the precipitates generated by air oxidation of the ferrous solution at pH 11 show that sulfated green rust first precipitates as mediate, which is oxidized further, hydrolyzed, dehydrated and finally becomes Co-ferrite. As Fe/Co molar ratio decreases, the cobalt part in the ferrite increases but the percentage of the cobalt precipitated into the ferrite to total one in the feed solution decreases. Higher temperature was found do not favorite the substitute of ferrous with cobalt.