(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083； 2. 中國恩菲工程技術(shù)有限公司，北京 100038)
摘 要: 結(jié)合相關(guān)熱力學(xué)計算結(jié)果，推測鈉硅渣在氧化鋁熟料燒結(jié)法處理過程中存在的多級反應(yīng)及其產(chǎn)物組成，并通過研究鈉硅渣在不同條件下的反應(yīng)行為，驗證中間相Na2-xAl2-xSixO4的存在及其溶出性能的差異。結(jié)果表明：在燒結(jié)過程中，硅系數(shù)x為0、0.05、0.25、0.35、0.45、0.55、0.85的Na2-xAl2-xSixO4均可以生成；燒結(jié)產(chǎn)物組成形態(tài)受反應(yīng)溫度和生料配比影響；當配鈣比為2、燒結(jié)溫度由750 ℃升高至1200 ℃時，或當配鈣比由1.0升高至2.5、溫度為900 ℃時，反應(yīng)產(chǎn)物的硅系數(shù)x均可由0.85逐漸下降至0；硅系數(shù)決定反應(yīng)產(chǎn)物的溶出性能，當x≤0.25時，Na2-xAl2-xSixO4中間相可以溶解于鋁酸鈉溶液。
關(guān)鍵字: 燒結(jié)法；鈉硅渣；石灰；硅系數(shù)
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China; 2. The China ENFI Engineering Co., Ltd., Beijing 100038, China）
Abstract:According to the thermodynamic calculation, the multistage reaction and the product composition of sodium hydrate alumino-silicate were proposed in alumina sintering process. The presence of Na2-xAl2-xSixO4 and the differences of dissolution performance were confirmed by the reactions of sodium hydrate alumino-silicate under different conditions. The results show that all the Na2-xAl2-xSixO4 (x=0, 0.05, 0.25, 0.35, 0.45, 0.55, 0.85) can be formed in the alumina sintering process. And the composition of sintering products were influenced by sintering temperature and raw material proportioning. The silicon coefficient (x) of Na2-xAl2-xSixO4 can reduce from 0.85 to 0 gradually with the sintering temperature ranging from 750 ℃ to 1200 ℃ (mole ratio of CaO to SiO2 is 2), or the mole ratio of CaO to SiO2 increasing from 1 to 2.5 (sintering temperature 900 ℃). The dissolution performance of Na2-xAl2-xSixO4 was determined by the silicon coefficient (x), and the Na2-xAl2-xSixO4 can be dissolved in sodium aluminate solution with x≤0.25.
Key words: sintering; sodium hydrate alumino-silicate; lime; silicon coefficient
