化工进展2017，Vol.36Issue(7)：2400-2406,7.DOI:10.16085/j.issn.1000-6613.2016-1331
CO2海水脱钙后主要体系中镁盐的结晶
Research on the crystallization process of magnesium salt in major system of decalcified seawater
摘要
Abstract
There are a large number of magnesium ions and bicarbonate ions left in the system that after seawater decalcification using carbon dioxide,which can lead to scaling problem due to the low solubility of magnesium salts when the treated seawater is used.The new approach proposed in this article is that bicarbonate ions are transformed to carbonate ions and combined with magnesium ions by using sodium hydroxide as precipitant,which results in the further utilization of magnesium resources and mineralization of carbon resources.The effect of mole ratio between hydroxyl ion in the alkali resource and magnesium ions on magnesium removal rates was investigated under the temperature of 10℃,40℃ and 60℃,respectively.The corresponding sediments were characterized by XRD and SEM.And the relationship between the value of n(OH-)/n(Mg2+) and the kinds and morphology of the sediment was obtained.The main conclusions are as follows:the magnesium removal rates increased with the increase of the amount of sodium hydroxide added,and the rates can reach over 98％.At 10℃,the precipitates existed in the form of pure MgCO3·3H2O,Mg5(CO3)4(OH)2·5H2O and Mg(OH)2 or their mixtures.At 40℃,MgCO3·3H2O disappeared,and the sediments were consist of pure Mg5(CO3)4(OH)2·4H2O and Mg(OH)2 or mixtures.This study provided a new approach for further utilization and mineralization of carbon dioxide of the decalcified seawater using flue gas,and provided a reference for detailed research on the extraction of magnesium resources.关键词
提镁/碳矿化/沉淀结晶Key words
magnesium extraction/mineralization of carbon dioxide/precipitation crystallization分类
化学化工引用本文复制引用
赵颖颖,张焱,邢贞干,纪志永,王军,袁俊生..CO2海水脱钙后主要体系中镁盐的结晶[J].化工进展,2017,36(7):2400-2406,7.基金项目
国家自然科学基金(21306037、21406051)、国家科技支撑计划(2015BAB09B00)、天津市自然科学基金(13JCQNJC05600、14JCYBJC20700)、河北省高层次人才资助项目(C2013003041)、河北省科技计划(14273105D)及河北省自然科学基金(B2014202090)项目. （21306037、21406051）
