辽宁科技大学本科生毕业设计 第 I 页
摘 要
现设计一个年产95万吨氧化铝车间，设计生产方法采用目前工艺流程最简单，综合能耗较低的拜耳法。本设计进行了各项冶金指标数据的计算，包括全厂物料平衡计算、全厂工艺设备的选择与计算、高压溶出车间工艺流程及工艺条件的选择与论证、高压溶出车间热平衡计算以及高压溶出车间主要工艺设备的选择与计算。粉碎设备中采用圆锥破碎机，用棒磨机进而水力旋流器的短筒球磨机进行作业。赤泥洗涤设备采用大型平地沉降槽。在进行铝酸钠溶液分解过程中，冷却时采用板式热交换器。种分母液分解蒸发采用五效降膜蒸发器，在高压溶出车间中采用我国自行研发的管道预热—停留罐溶出技术。同时对厂区进行环境保护的论证，最后形成了工程图纸。
关键词：拜耳法；氧化铝；五效降膜蒸发器；管道预热—停留罐溶出
辽宁科技大学本科生毕业设计 第 II 页
Abstract:
Now designed annual output of 850,000 tons of alumina a factory design and production methods of the present process using the most simple, comprehensive energy consumption of a low lime Bayer. The design of various metallurgical calculation of index data, including the whole plant material balance calculation, the whole plant selection and calculation of process equipment, high pressure leaching process and plant selection and demonstration of process conditions, high pressure leaching plant heat balance calculations and high pressure leaching plant major process equipment selection and calculation. Grinding equipment used cone crusher, and then with the rod mill ball mill hydrocyclone Duantong operate. Red mud washing equipment using large-scale ground subsidence trough. During the decomposition of sodium aluminate solution, the cooling plate heat exchanger used. Seed decomposition liquor evaporation using a five-effect falling film evaporator, high pressure leaching plant in our own research and development in the pipeline with warm - stay tank leaching technology. At the same time demonstration plant for environmental protection, and finally formed the engineering drawings.
Key word: Bayer; Alumina; Five-effect falling film evaporator; Pipes warm - stay dissolution tank
辽宁科技大学本科生毕业设计 第 III 页
1 综述 ................................................................................................................................ 1
1.1我国铝土矿资源分布及其特点 .......................................................................... 1 1.2我国氧化铝工业概况 .......................................................................................... 2 1.3我国氧化铝基本生产方法 .................................................................................. 2
1.3.1烧结法 ....................................................................................................... 3 1.3.2拜耳—烧结联合法 ................................................................................... 3 1.3.3拜耳法 ....................................................................................................... 3 1.4拜耳法生产氧化铝 .............................................................................................. 4
1.4.1主要生产过程 ........................................................................................... 4 1.4.2生产基本流程 ........................................................................................... 4 1.4.3拜耳法的特点 ........................................................................................... 5 1.5氧化铝厂设计的作用 .......................................................................................... 5 1.6设计主要内容 ...................................................................................................... 5 2 物料衡算 ........................................................................................................................ 6
2.1全厂主要生产工艺流程 ...................................................................................... 6 2.2原料成分及主要工艺技术条件 .......................................................................... 6
2.2.1原料成分 ................................................................................................... 6 2.2.2主要工艺技术条件 ................................................................................... 7 2.3生产过程物料衡算 .............................................................................................. 8
2.3.1氧化铝总回收率 ....................................................................................... 8 2.3.2原矿浆配制 ............................................................................................... 8 2.3.3高压溶出 ................................................................................................. 14 2.3.4矿浆稀释、赤泥分离及洗涤 ................................................................. 15 2.3.5精液分解和种分母液蒸发 ..................................................................... 24 2.3.6氢氧化铝焙烧 ......................................................................................... 27 2.3.7主要技术经济指标 ................................................................................. 27 2.4全厂物料流量表 ................................................................................................ 28 3 工艺设备的选择与计算 .............................................................................................. 31
3.1 矿石粉碎设备 ................................................................................................... 31
辽宁科技大学本科生毕业设计 第 IV 页
3.2 铝土矿溶出设备 ............................................................................................... 31 3.3 赤泥的分离与洗涤设备 ................................................................................... 32
3.3.1分离设备 ................................................................................................. 32 3.3.2 洗涤设备 ................................................................................................ 33 3.4 初液控制过滤设备 ........................................................................................... 33 3.5 铝酸钠溶液分解设备 ....................................................................................... 34
3.5.1 分解原液冷却设备 ................................................................................ 34 3.5.2 种分解槽的选择与计算 ........................................................................ 35 3.5.3 氢氧化铝分离和洗涤设备 .................................................................... 36 3.6 氢氧化铝焙烧设备 ........................................................................................... 36 3.7 种分母液蒸发设备 ........................................................................................... 37 4高压溶出车间工艺流程及工艺条件的选择与论证 ................................................... 38 5 高压溶出车间热平衡计算 .......................................................................................... 40
5.1 溶出矿浆自蒸发级数的确定 ........................................................................... 40 5.2 各级自蒸发器参数 ........................................................................................... 40 5.3 矿浆的自蒸发水量 ........................................................................................... 40 5.4 原矿浆由溶出矿浆的自蒸发蒸汽预热的温度 ............................................... 41 5.5 原矿浆由新蒸汽冷凝水预热的温度 ............................................................... 43 5.6 原矿浆预热后的温度 ....................................................................................... 45 5.7 进出各级预热器的蒸汽与矿浆的平均温度差 ............................................... 47 6 高压溶出车间主要工艺设备的选择与计算 .............................................................. 49
6.1预热器的选择与计算 ........................................................................................ 49
6.1.1预热器的传热面积计算公式 ................................................................. 50 6.1.2预热器的规格及数量 ............................................................................. 53 6.2 自蒸发器的选择与计算 ................................................................................... 53 6.3油压泵的选择与计算 ........................................................................................ 55
6.3.1溶出器系统的阻力损失计算方法 ......................................................... 55 6.3.2溶出器系统阻力损失的计算 ................................................................. 56 6.3.3 1号自蒸发器的矿浆饱和蒸气压 .......................................................... 58
辽宁科技大学本科生毕业设计 第 V 页
6.3.4油压泵的总工作压力 ............................................................................. 58 6.3.5油压泵的选型与数量 ............................................................................. 58
7环境保护和综合利用 ................................................................................................... 59
7.1氧化铝厂对环境的影响 .................................................................................... 59
7.1.1废气和粉尘的污染 ................................................................................. 59 7.1.2废水的污染 ............................................................................................. 59 7.1.3赤泥的污染 ............................................................................................. 59 7.2处理方法 ............................................................................................................ 60
7.2.1 化工污水的一般处理方法 .................................................................... 60 7.2.2 废渣的处理 ............................................................................................ 60 7.2.3 废气的处理 ............................................................................................ 60 结论 .......................................................................................................................... 61 致谢 .......................................................................................................................... 62 参考文献 .................................................................................................................. 63