【作者】 黎志英；

【导师】 何润德；

【作者基本信息】 贵州大学 ， 有色金属冶金， 2006， 硕士

【摘要】 我国具有较丰富的铝土矿资源，其中高硫铝土矿中高品位铝土矿占57.2％，贵州高硫型铝土矿60％以上属于高品位铝土矿，这种高硫型高品位铝土矿适用于拜耳法处理。如能充分利用这部分铝土矿资源将会大大的减轻资源的负担。 本文在一水硬铝石高温高压溶出理论的基础上，对贵州高硫高品位铝土矿进行了溶出性能研究。就拜耳法工序环节来说，为了减轻溶出液的脱硫负担，减少脱硫剂用量，降低除硫费用，就必须控制适宜的高压溶出条件，在保证有较高氧化铝溶出率的前提下，使矿石中的硫尽可能少地进入溶出液。因此很有必要对高硫型高品位铝土矿的溶出性能进行深入地研究。 采用正交实验方法，考查了石灰添加量、溶出温度、苛性碱浓度和溶出时间对贵州高硫铝土矿的氧化铝溶出率的影响以及铝土矿的硫向溶液中的转化率(即硫的溶出率)的影响，并且对贵州高硫铝土矿的氧化铝、硫的溶出率进行了最优分析，得到最佳溶出条件的数学模型及获得了适宜的溶出工艺条件。实验结果表明，溶出高硫铝土矿较适宜的条件是：温度260℃，碱浓度195g／l，石灰添加量CaO12％，时间50min。此时，高硫铝土矿中的氧化铝溶出率高达88％、硫的溶出率仅为13％。从而为生产中有效利用贵州高硫铝土矿提供参考。 同时还研究了给定条件下不同硫含量的铝土矿硫的溶出率和稀释溶出矿浆沉降试验。 研究结果表明，溶出温度对溶出率的影响最大、石灰添加量次之、溶出时间和苛性碱浓度的影响较小；铝土矿的硫在中等硫含量时，硫的溶出率较低：稀释矿浆的沉降性能好，压缩液固比小。更多还原

【Abstract】 There are abundant resources of bauxite ore in our country .The total sum of high grade bauxite containing sulfur is 57.2% ,and more than 60% of high grade bauxite containing sulfur of Guizhou belongs to this ore ,the Bayer pressure is applicable to handle this ore .It will reduce the burden of bauxite resource if we are able to exploit/utilize this kind of bauxite ore efficiently .So first we must resolve the desulfurizing problem of technological process in producing alumina .This paper studies the leaching function of high grade bauxite containing sulfur of Guizhou according to the high-pressure digestion theory of the diaspore bauxite .As far as working procedure segment of Bayer method is concerned , in order to reduce the desulfurizing burden of digested slurry , the quantity of desulfurization and the cost of desulfurizing, we must control suitable high-pressure digestion condition .Under the premise of gaining the high yield of Al₂O₃,we should try our best to keep the sulfur out of liquid .So it is necessary for us to study the leaching function of high grade bauxite containing sulfur deeply .Discussing the effect parameters of leaching ratio among the four influencing factors : alkali-consistency , leaching-temperature , alkali-consistency and leaching-time , the optimal analysis about the digestion of Guizhou high grade bauxite containing sulfur adopting orthogonal cross-course analysis have been made , the mathematic model of optimal digestion condition have been found and the suitable condition of leaching technology have been gained .It’s optimum conditions are that leaching-temperature is 260℃,alkali-consistency 195 g/l , CaO 12 % and leaching-time 50min. In this optimum condition, the yield of Al₂O₃ reaches no less than 88 %±, the yield of sulfur reaches no more than 13 %±. Thus all this can offer reference to efficiently using high grade bauxite containing sulfur of Guizhou in producing.At the same time , this paper studies the leaching function of bauxite containing different amount of sulfur under the given conditions and the depositing ability of diluted Bayer process’s digested slurry .The result points out: the leaching-temperature affect the digestion rate greatly , the following is the quantity of lime , leaching-time and alkali-consistency affect the digestion rate smaller ; sulfureous leaching rate is lower when sulfur of bauxite ore is the middle content ; the depositing ability of diluted digested slurry is good and compressed L/S is small .更多还原