中南大学本科生毕业设计说明书摘要摘 要本设计的任务是设计年产量为 80 万吨的氧化铝厂。通过对国内外各种氧化铝生产 工艺进行广泛深入的分析和对比，并根据本设计的具体条件，确立了本设计的工艺流程（拜耳法生产氧化铝）。经过论证，确定了生产的工艺参数：分解溶液的配料比k 为 1.45，精液碱浓度为 158.66g/l；母液k 为 3.0，溶出碱浓度为 240 g/L；溶出温度 260，溶出 赤泥 A/S=1.40，N/S=0.3，赤泥分离底流 L/S=1.5，赤泥洗涤底流 L/S=1.0。在以上参数 的基础上确立了本设计的工艺流程：管道化压煮器溶出两次深锥赤泥沉降分离、四 次深锥赤泥洗涤二段晶种分解流态化闪速焙烧母液蒸发。其中，本次设计的重点 是赤泥洗涤车间。通过计算分析，设计了四次反向洗涤的工艺流程，并对热损失进行了 验算。同时，还对全厂生产成本进行了计算，对沉降车间的工作人员进行分配。最后， 针对氧化铝生产会产生的主要环境污染，制定了具体的处理措施。关键字：氧化铝；拜尔法；赤泥；沉降i中南大学本科生毕业设计任务书AbstractAbstractThe task is to design an output of 800 thousand tons of alumina refinery. Based on extensive analysis of the international and domestic alumina production technology and the specific requirements of the design, the production process (Bayer process) is established. The parameters of production process are obtained as fallowed: the k , Nk of pregnant liquor is1.45 and 158.66 g/l , respectively; the k, Nk of spent liquor is 3.0 and 240g/l,respectively;the digesting temperature is 260, the A/S of red mud is 1.40,and N/S is 0.3;the L/S ofsedimentation red mud is 1.5,and 1.0 of the washing red mud. On the basis of the above parameters, the technology is established as fallowes: tube-autoclave digestiontwo deep cone settling tank and four deep cone settling tank red mud sedimentation and washingtwo-stage precipitationfluidization flash calcinationvaporizing spent liquor. The keynote of these is to design the red mud washing workshop. A process containing four-time reversed washing is designed. Moreover, its heat loss is calculated. Meanwhile, the cost of the plant is also calculated, and the staff of the red mud washing workshop has been allocated as well. Finally, specific measures are established because of the main pollution of the alumina production.Key words: alumina; Bayer process; red mud; sedimentationii中南大学本科生毕业设计说明书目录目 录摘 要.I ABSTRACT. II绪 论. 1第 1 章 厂址和生产能力的选择与论证. 81.1 厂址的选择与论证. 81.2 生产能力的选择和论证. 10第 2 章 生产方法、工艺流程及主要技术、经济指标的选择与论证. 122.1 氧化铝生产方法现状. 122.1.1 拜尔法. 122.1.2 石灰石烧结法. 122.1.3 拜尔-烧结联合法. 132.1.4 其他方法. 142.2 生产方法的选择与论证. 152.3 工艺流程的选择与论证. 162.3.1 原料准备. 162.3.2 预脱硅. 172.3.3 高压溶出. 172.3.4 赤泥沉降分离及洗涤. 202.3.5 赤泥干法输送、堆存. 282.3.6 铝酸钠溶液控制过滤. 292.3.7 晶种分解. 302.3.8 氢氧化铝过滤. 322.3.9 氢氧化铝焙烧. 332.3.10 母液蒸发.