两段烧结工艺中的Ⅰ段赤泥烧结

SINTERING RED MUD FROM Ⅰ STAGE SINTERING IN TWO STAGE SINTERING PROCESS OF BAUXITE

研究了铝土矿两段烧结工艺的Ⅱ段烧结及溶出的最佳操作条件，确定Ⅰ段赤泥在钙比为２３５，烧结温度为１１２０～１２００℃时，氧化钠溶出率达９２％左右，氧化铝溶出率达８１％左右；当溶出液氧化铝质量浓度为４０～８０ｇ／Ｌ时，Ⅱ段熟料溶出的二次反应很弱，溶出条件宽松．因此，两段烧结新工艺处理铝硅比为６的矿石，氧化钠总溶出率达９８６％，氧化铝总溶出率达９６８％，碱的化学损失是每吨氧化铝损失碳酸钠１８ｋｇ．

In this paper, the optimum conditions for Ⅱ stage sintering and leaching its sinter in two stage sintering technology have been investigated. When the red mud from leaching Ⅰ stage sinter is sintered at 1120～1200 ℃ and /=2 35, the yields of Na 2O and Al 2O 3 are about 92% and 81% respectively. When the Al 2O 3 concentration in pregnant liquor after leaching Ⅱ stage sinter is 40～80 g/L, the secondary reaction in leaching is very weak. Thus, when bauxite with w (A)/ w (S)=6 is processed by two stage sintering technology, the final yields of Na 2O and Al 2O 3 are 98 6% and 96 8% respectively and the chemical loss of Na 2CO 3 is about 18 kg per ton Al 2O 3.