拜耳法砂状氧化铝生产过程氢氧化铝粒度控制的研究.pdf

中南大学
硕士学位论文
拜耳法砂状氧化铝生产过程氢氧化铝粒度控制的研究
姓名:项庆煜
申请学位级别:硕士
专业:化学工程
指导教师:满瑞林
20060101
工程硕士学位论文
摘要
摘要
本文研究和完善了山东铝业股份有限公司拜尔法生产流程,探索了成
核、附聚、长大及磨蚀等影响拜尔法生产砂状氧化铝的主要因素,通
过分离去除细颗粒氢氧化铝,添加结晶助剂和高温附聚等手段,可生
产出符合要求的砂状氧化铝。
研究表明,通过三级旋流器组串并联分级,可将溢流中小于45
um颗粒由5%~26%增加到18%~65%。由于碳分晶种的粒径大于
45um质量百分比在90%左右,而粒径小于15pm的个数百分比在
93%~98%,粒度分布两极分化,添加碳分晶种不利于生成砂状氧化
铝。实验发现,结晶助剂循环连续加入后,溶液中的草酸根减少,有
利于氢氧化铝附聚与结晶,可以提高分解率。
高温附聚实验表明:当固含控制在120g1以下,附聚温度在75~
80℃,小于15m颗粒附聚效果很明显,小于30pm的颗粒也有较好
的附聚效果。
长大实验表明:附聚后的氢氧化铝进入14个长大槽继续长大,
首槽温度控制在75℃,出料温度控制在50℃,氢氧化铝粒度明显增大,
小于45m的粒子比例由15%~60%减少到了5%~30%。
关键词:拜尔法,氢氧化铝,粒度,砂状氧化铝
工程硕士学位论文
ABSTRACT
ABSTRACT
In this paper the Bayer manufacture flow was improved in
Shandong aluminum company four affecting factors such as
nucleation、 agglomeration、 growing、 abrasion were studied.When
the fine Aluminum Hydroxide grains were separated , crystallization
dosage was added and high temperature was given, the size up alumina
was got.
The result indicates that in the three class revolve implement grump
series-parallel connection dispart experiment: particle size of less than
45um in the overflow increases to 18%-65% from 5%26%.the mass
percent of more than 45um carbonate seeding is 90%, the number
percent of less than 15um is 93%-98%, the particle size distributing is
polarized. Fine seeds and the second nucleation make the size of
aluminum hydroxide finer. Crystal dosage experiment is done to
aggregation fine particle, At the same time oxalic acid is reduced and
this is advantage to aggregate and grow. the decompounding rate is
increased
High temperature aggregation experiment result indicates that
solider percent is controlled less than 120/1, Temperature is 75--80C
The aggregation of particle size of less than 15 um aggregation is
evidence, The aggregation of particle size of less than 30 um is also
ide
ice
Growing experiment result indicates that aggregated aluminum
hydroxide is entered into fourteen slots to grow, The first slots
temperature is 70C, The last slot's temperature is 50C. Less than 45um
Aluminum hydroxide particle percent reduce from 15%60%to 5%
30%
KEY WORDS Bayer process, aluminum hydroxide, particle size, sandy
umina