改进沉淀法对高镁锂比卤水进行锂镁分离研究.pdf

Vol_.42,No.10
材
第42卷第10期
October 2016
Sichuan Building Materials
2016年10月
改进沉淀法对高镁锂比鹵水进行锂镁分离研究
庞莎莎,梁渠,刘凯,蔡静
(成都理工大学材料与化学化工学院化学系,四川成都610059
决我国高镁锂比盐湖卤水提锂的工艺难題。配制高镁锂比0前>"
摘要:高镁锂比盐湖卤水中锂镁分离提锂是一项需 ratio salt lake br
要攻克的技术难题。采用改进沉淀法进行锂镁分离,来解
卤水(p(Mg2t)=110g/1,p(i)=2.5g/1.,Mg/a
我国卤水锂资源非常丰富,以肯海盐湖锂资源储量为
=4),加入氯氧化镁晶种;以氯氧化钠为主沉淀剂,以吐主3。青海盐湖卤水镁锂比高,镁锂比在35.2~1825范
温-80、聚丙烯酰胺为辅助沉淀剂,进行沉淀除镁反应。?内变化。锂镁离子半径相近、化学性质相似,锂镁分
结果表明,沉淀反应生成的氩氧化镁易于过滤,锂损失率离变得困难。适用于高镁锂比卤水提锂的儿种方法5-6各
低于2%。通过对得到的沉淀进行SEM、LPSA表征,其沉有优缺点,而淀法能满足要求。只有Mg/i≤8オ可用
淀的结构和形态发生了很大的变化,得到了颗粒大而完差此法,若Mg/Li>8时,镁对沉淀锂造成了干扰。若用氢氧
的沉淀
化物先除镁,降低镁锂比,再淀锂,亦是一种有效地改
关键词:镁;锂;分离;高镁锂比卤水
进沉淀法。气氧化镁溶度积很小,而氧氧化锂是叮溶的,
中图分类号:TQ131.11
文献标志码:
所以氢氧化物对锂镁分离选择性高,但氢氧化镁易团聚
文章编号:1672-4011(2016)10-0206-02
本文用改进沉淀法来得到易过滤的沉淀和除镁率高、锂损
D)OI:10.3969/isn.1672-4011.2016.10.097
失率低的滤液。
实验部分
Study on the Separation of lithium and Magnesium
from High Mg/ Li Ratio Salt Lake Brine by the1.1主要试剂与药品
Improved Precipitation Method
试剂:聚丙烯酰胺(PAM)、聚乙烯吡咯烷(PVP)
PANG Shasha, LIANG (u, LIU Kai, CAI ding
聚丙烯酸(PAA)、止温-80、六水氯化镁、氯化锂、氰氧
( Department of Chemistry, College of Materials and Chemistry
化钠等,均为AR
Chemical Engineering, Chengdu University of Teehnology
仪器:原子吸收光谱仪、扫描电镜、激光粒度仪等
Chengdu 610059, China)
1.2实验步骤
Abstract At present, the separation of magnesium and
配制:高镁锂比模拟卤水[p(Mg2)=110gL;
lithium in salt lake containing high magnesium-lithium ratio is (li)=2.5 g/1; Mg/1i=441
a key technical problems in the development of salt lake
沉淀反应:取卤水,加人晶种;取NaOH溶液、PAM
brine. The improved precipitation method is used to solve the叶温-80,混合后加人到卤水中,陈化半小时,过滤、洗
problems that lithium is extracted by means of separation of the涤,记录过滤时间
high ratio of magnesium lithium from salt lake brine. High M/Li
测试与表征:滤液进行AAS测定,沉淀进行LPSA
ratio salt lae brine (p(Mg 2)=110 g/1: p(1i*)=2.5 g/1: Fr
Mg/li =44 ) is prepared, adding the magnesium hydroxide
2结果与讨论
crystal seed, and precipitation reaction for magnesium hydroxide
was proceeded by using sodium hydroxide as the main precipitat-2.1辅助沉淀剂的影响
ing agent, tween -80 and poly(acrylamide )regard as auxiliary
在相同实验条件下,改变辅助沉淀剂进行沉淀反应
precipitant, The results showed that the resulting precipitate of数据如图1。由图1知,辅助沉淀剂使过滤时间缩短,H
magnesium hydroxide was easy to filter, lithium- ion adsorption PAM的效果最好。
loss rate of less than 2%. Using SEM, IPSA, the results
埋损火率
showed that the morphology and structure of magnesium hydrox-
le precipitate have been changed effectively and the large granu
lar and solitary precipitate could be got by using the improved
precipitation method
Key words: magnesium; lithium; separation; high Mg/I
前助沉淀剂
作者简介:庞莎莎(1991-),女,四川绵阳人,硕士研究生,主要研究
图1辅助沉淀剂的影响
图2PAM量的影响
方向:盐湖卤水锂镁分离材料研究
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