水合硝酸镁热解过程研究
收稿日期: 2021-02-24
网络出版日期: 2021-12-16
Study on pyrolysis process of Mg（NO3）2·nH2O
Received date: 2021-02-24
Online published: 2021-12-16
水合硝酸镁是红土镍矿硝酸湿法冶金工艺中产生的副产品,其资源化利用是决定湿法冶金工艺绿色化工艺链条贯通的关键环节之一。水合硝酸镁热解生产氧化镁是其资源化利用最具潜力的发展方向。为此,以稳定的硝酸镁水合物——六水硝酸镁为实验物料,采用热重分析（TG-DTG）、红外光谱（FT-IR）、X射线衍射（XRD）和差示扫描量热分析（DSC）等技术手段研究了其热解基本过程,旨在为水合硝酸镁资源化工艺参数的确定提供理论支撑。研究结果表明,水合硝酸镁热解过程可以分为脱水和分解两个阶段：脱水阶段,六水硝酸镁在68~170 ℃失去4个结晶水生成二水硝酸镁,二水硝酸镁在170~389 ℃失去2个结晶水生成无水硝酸镁;分解阶段,无水硝酸镁在389~510 ℃分解生成氧化镁、二氧化氮和氧气。六水硝酸镁热解过程是一个吸热反应,其反应热约为940.50 J/g。
陈雪 , 张孟辉 , 赵亮 , 董辉 , 王德喜 . 水合硝酸镁热解过程研究[J]. 无机盐工业, 2021 , 53(12) : 91 -94 . DOI: 10.19964/j.issn.1006-4990.2021-0113
Mg（NO3）2·nH2O is a by-product produced in the nitric acid hydrometallurgical process of laterite nickel ore.Its resource utilization is one of the key links in the green hydrometallurgical process chain.MgO can be obtained by pyrolysis of Mg（NO3）2·nH2O,which is the most potential development direction of its resource utilization.Therefore,stable magnesium nitrate hydrate Mg（NO3）2·6H2O was used as experimental material,and the basic pyrolysis process was studied by means of TG-DTG,TG-FTIR,XRD and DSC,in order to provide theoretical support for the determination of process parameters of magnesium nitrate hexahydrate.The research results showed that the pyrolysis process of Mg（NO3）2·nH2O could be divided into two stages: dehydration and decomposition.The dehydration process was divided into two stages：Mg（NO3）2·6H2O lost four crystal water to form Mg（NO3）2·2H2O at 68~170 ℃;Mg（NO3）2·2H2O lost two crystal water to form Mg（NO3）2 at 170~389 ℃.Decomposition process：Mg（NO3）2 was decomposed into MgO,NO2 and O2 at 389~510 ℃.Mg（NO3）2·6H2O pyrolysis was an endothermic reaction,and its reaction heat was about 940.50 J/g.
Key words： Mg（NO3）2·nH2O; pyrolysis; resource utilization; dehydration; decomposition
| [1] | KIM J, DODBIBA G, TANNO H, et al. Calcination of low-grade late- rite for concentration of Ni by magnetic separation[J]. Minerals Engineering, 2010, 23(4):282-288. |
| [2] | LOVEDAY B K. The use of oxygen in high pressure acid leaching of nickel laterites[J]. Minerals Engineering, 2008, 21(7):533-538. |
| [3] | 王成彦, 曹志河, 马保中, 等. 红土镍矿硝酸加压浸出工艺[J]. 过程工程学报, 2019, 19(S1):51-57. |
| [4] | MADARASZ J, VARGA P P, POKOL G. Evolved gas analyses(TG/ DTA-MS and TG-FTIR) on dehydration and pyrolysis of magne- sium nitrate hexahydrate in air and nitrogen[J]. Journal of Analytical & Applied Pyrolysis, 2007, 79(1/2):475-478. |
| [5] | PRADITA T, SHIH S J, AJI B B, et al. Synthesis of mgo powder from magnesium nitrate using spray pyrolysis[C]//Proceedings from the 14th International Symposium on Therapeutic Ultrasound.Las Ve- gas:International Conference on Chemistry, 2017:1-5. |
| [6] | MIKULI E, MIGDAL-MIKULI A, CHYZY R, et al. Melting and th- ermal decomposition of[Ni(H2O)6](NO3)2[J]. Thermochimica Acta, 2001, 370(1/2):65-71. |
| [7] | 齐之锴, 李鹏, 房俊卓. 热分析法研究CuSO4·5H2O结构[J]. 宁夏大学学报:自然科学版, 2019, 40(3):277-280. |
| [8] | DU J, ZHANG L, SONG S, et al. Effect of potentially toxic metals (PTMs) on the thermal decomposition of phytoremediation plant wastes:Thermokinetic and gas evolution analysis by TG-DTG- MS[J]. Bioresource Technology, 2019, 293:122-127. |
| [9] | 艾明欢, 杨菁, 沈轶, 等. TG-FTIR联用研究HnB烟草基质在400 ℃以下的热解特性和气相产物[J]. 中国烟草学报, 2020, 26(1):8-14. |
| [10] | PANSHINA S, BAKIBARV A, PONOMARENKO V, et al. Analysis of XRD structural parameters of glycoluril and its derivatives[J]. Journal of Structural Chemistry, 2020, 61(9):1315-1355. |
| [11] | 林伟豪, 高致慧, 杨勇, 等. 基于激光光谱差分法检测NO2[J]. 激光技术, 2014, 38(6):835-838. |
| [12] | 董雪, 亓利剑, 周征宇, 等. 水热法合成红色绿柱石的光谱特征研究及应用[J]. 光谱学与光谱分析, 2019, 39(2):517-521. |
| [13] | 纪爱亮, 吴桂叶, 刘崇峻, 等. 气相色谱法快速测定乙硫氨酯含量[J]. 现代化工, 2020, 40(S1):313-315. |
/
| 〈 |
|
〉 |
