(中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083)
摘 要: 研究了高鐵三水鋁石型鋁土礦燒結(jié)過程中Al2O3與CaCO3、CaO、SiO2及FeO反應(yīng)的熱力學(xué)規(guī)律。結(jié)果表明：在1 473~1 673 K溫度下，Al2O3比Fe2O3更易與CaCO3反應(yīng)；Al2O3與鐵酸鈣(2CaO∙Fe2O3和CaO∙Fe2O3)反應(yīng)不能生成3CaO∙Al2O3，當(dāng)燒結(jié)溫度大于1 000 K時(shí)，可以與2CaO∙Fe2O3反應(yīng)生成12CaO∙7Al2O3；SiO2比Al2O3更易與CaO結(jié)合，Al2O3與SiO2直接反應(yīng)生成硅酸鋁的可能性較小；當(dāng)燒結(jié)溫度為1 473~1 673 K時(shí)，除CaO∙2Al2O3和CaO∙Al2O3不能向3CaO∙SiO2轉(zhuǎn)變外，其余鋁酸鈣均可在SiO2的作用下向硅酸鈣轉(zhuǎn)變；2CaO∙Al2O3·SiO2是CaO、Al2O3和SiO2三者直接反應(yīng)的產(chǎn)物，不能由硅酸鈣和鋁酸鈣相互反應(yīng)生成；CaO、Fe2O3、Al2O3和SiO2四元礦物存在時(shí)，燒結(jié)過程優(yōu)先生成2CaO·Al2O3·SiO2和4CaO·Al2O3·Fe2O3，這與燒結(jié)實(shí)驗(yàn)結(jié)果相符。
關(guān)鍵字: 三水鋁石; 鋁土礦；鐵礦石；燒結(jié)；氧化鋁
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The thermodynamics of the reactions of alumina(Al2O3) with CaCO3, CaO, SiO2 and FeO in the sintering process of high-iron gibbsite-type bauxite was investigated. The results show that alumina reacts with calcium carbonate much easier than ferri oxide(Fe2O3) at the industrial sintering temperature of 1 473−1 673 K. Alumina can not react with calcium ferrites(2CaO∙Fe2O3 and CaO∙Fe2O3) to form 3CaO∙Al2O3, but when temperature is over 1 000 K alumina reacts with 2CaO∙Fe2O3 to form 12CaO∙7Al2O3. SiO2 reacts with CaO much easier than Al2O3. The possibility of alumina silicate from direct reaction of Al2O3 with SiO2 is little. Except for CaO∙2Al2O3 and CaO∙Al2O3, the other calcium aluminates can transform into calcium silicate by reacting with SiO2. Gehlenite(2CaO∙Al2O3∙SiO2) can not be formed from the reaction of calcium silicate(CaO∙SiO2) with calcium aluminate(CaO∙Al2O3), but it can be directly formed from the reaction of CaO, Al2O3 and SiO2. When CaO, Fe2O3, Al2O3 and SiO2 coexist in the sintering process, they are more likely to form ternary compound 2CaO·Al2O3·SiO2 and 4CaO∙Al2O3∙Fe2O3, which is consistent with the sintering results in laboratory.
Key words: gibbsite; bauxite; iron ore; sintering; alumina
