The solubility and stability of nesquehonite (MgCO3路 3H2O) in Na-Mg-NH4-Cl brines
文献类型：会议论文
| 作者 | Dong, Mei1; Cheng, Wenting1; Li, Zhibao1; Duan, Dongping1; Demopoulos, George P.2 |
| 出版日期 | 1905-06-30 |
| 会议日期 | August 17, 2008 - August 21, 2008 |
| 会议地点 | Phoenix, AZ, United states |
| 关键词 | Magnesia - Magnesite - Precipitation (chemical) - Sodium chloride - Stability |
| 页码 | 1166-1176 |
| 英文摘要 | Approximately 20 million tonnes of magnesium chloride per year are discarded as by-product or waste of the potassium fertilizer industry in Qinghai province of China. This has caused not only the wasting of valuable magnesium resources, but also a serious environmental problem. However, magnesium chloride (or bischofite) has a huge variety of applications in industry. Most importantly, it is a raw material for production of magnesium oxide, magnesium hydroxide and magnesium metal. Approximately one hundred kilograms of magnesium metal can be produced from 1 cubic meter of bischofite saturated brine. For this reason a novel process was proposed in this work to exploit the extraction and utilization of magnesium resources existing in discarded brine. In this process nesquehonite (MgCO3路3H2O), one of magnesium's important mineral compounds, was selected as a target precipitate due to its good filtration properties and its excellent dewatering characteristics. The determination of the stability and solubility of nesquehonite (MgCO 3路3H2O) in salt lake brine is an important requirement in developing, designing, and optimizing precipitation processes in which nesquehonite is precipitated by the reaction of MgCl2 brine with (NH4)2CO3 or Na2CO3. This work reports the results of experimental investigation on the stability and solubility of nesquehonite in relevant salt brines (NaCl, NH4Cl and MgCl2) in the temperature range of 298 to 323 K. The well-shaped nesquehonite used in this work was carefully prepared by the reaction of analytically pure MgCl2 with Na2CO3. The concentration investigated for all salts is up to 4 moldm-3 at ambient temperature. The solubility of nesquehonite in pure water was found to decrease with temperature within the temperature range in which nesquehonite is a stable phase. In pure NaCl brine, increasing the salt concentration initially causes the solubility of nesquehonite to increase reaching a maximum value and then decrease gradually with further increasing salt concentration. It is found that the addition of MgCl2 or NH4Cl also cause the solubility of nesquehonite to increase due to apparent complexation. XRD and SEM were employed to detect phase transformations. Results show that nesquehonite can be a stable phase in pure water up to 323 K while the stable region of nesquehonite becomes small in concentrated brines. |
| 资助机构 | Society for Mining, Metallurgy and Exploration |
| 会议录 | Hydrometallurgy 2008: 6th International Symposium
 |
| 学科主题 | Solubility |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/59558]  |
| 作者单位 | 1.Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080, China 2.Department of Mining, Materials Engineering, McGill University, 3610 University Street, Montreal, QC H3A 2B2, Canada |
| 推荐引用方式 GB/T 7714 | Dong, Mei,Cheng, Wenting,Li, Zhibao,等. The solubility and stability of nesquehonite (MgCO3路 3H2O) in Na-Mg-NH4-Cl brines[C]. 见:. Phoenix, AZ, United states. August 17, 2008 - August 21, 2008. |
入库方式： OAI收割
来源：过程工程研究所
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