Mechanistic Study of Magnesium Carbonate Semibatch Reactive Crystallization with Magnesium Hydroxide and CO2

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• 作者：Bing Han ; Haiyan Qu ; Harri Niemi ; Zuoliang Sha ; Marjatta Louhi-Kultanen
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：July 30, 2014
• 年：2014
• 卷：53
• 期：30
• 页码：12077-12082
• 全文大小：328K
• ISSN：1520-5045

文摘

This work investigates semibatch precipitation of magnesium carbonate at ambient temperature and pressure using Mg(OH)₂ and CO₂ as starting materials. A thermal analysis method was developed that reflects the dissolution rate of Mg(OH)₂ and the formation of magnesium carbonate. The method was successfully used to determine the composition of solids precipitated from the reaction. Concentration profiles of Mg²⁺ and total carbon over time were determined from the liquid phase. The influence of CO₂ flow rate and stirring rate on precipitation was analyzed based on comprehensive information from the liquid and solid phases. A stirring rate of 650 rpm was found to be the optimum speed as the flow rate of CO₂ was 1 L/min. Precipitation rate increased with gas flow rate, which indicates that mass transfer of CO₂ plays a critical role in this precipitation case. Magnesium carbonate trihydrate (nesquehonite) was formed as a bunch of needle-like primary crystals.