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过程工程学报 ›› 2018, Vol. 18 ›› Issue (2): 369-374.DOI: 10.12034/j.issn.1009-606X.217279

• 过程与工艺 • 上一篇    下一篇

红土镍矿与硫酸钠共热解动力学及其机理分析

杨 颂1*, 刘守军1,史鹏政2, 杜文广1,上官炬3, 赵艳平2     

  1. 1. 太原理工大学化学化工学院,山西 太原 030024;2. 太原科瑞康洁净能源有限公司,山西 太原 030006; 3. 煤科学与技术教育部和山西省重点实验室,山西 太原 030024
  • 收稿日期:2017-07-18 修回日期:2017-08-23 出版日期:2018-04-22 发布日期:2018-04-10
  • 通讯作者: 杨颂 yangsong@tyut.edu.cn

Thermal Decomposition Kinetics and Mechanism of Sodium Sulfate with Nickel Laterite Ores

Song YANG1*,  Shoujun LIU1 ,  Pengzheng SHI2,   Wenguang DU1 ,  Ju SHANGGUAN3,  Yanping ZHAO2     

  1. 1. College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China; 2. Taiyuan Green Coke Clean Energy Co., Ltd., Taiyuan, Shanxi 030006, China; 3. Key Laboratory for Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan, Shanxi 030024, China
  • Received:2017-07-18 Revised:2017-08-23 Online:2018-04-22 Published:2018-04-10

摘要: 采用热重?质谱联用技术,结合XRD分析,考察了红土镍矿与Na2SO4共热解的特性,对热解气态产物进行了分析. 结果表明,红土镍矿与硫酸钠共热解可分为5个阶段:游离水析出阶段(37?152℃)、针铁矿分解脱羟基阶段(238?278℃)、利蛇纹石和高岭土脱羟基阶段(554?602℃)、白云石分解阶段(892?914℃)和Na2SO4分解阶段(1241?1286℃). H2O, CO2和SO2是红土镍矿与硫酸钠共热解过程析出的主要气体. 根据Coasts模型,红土镍矿与硫酸钠共热解为一级反应,热解机制是Na2SO4中的Na+取代富镍硅酸盐中的Ni2+,被置换出的Ni2+与游离氧结合形成NiO,有利于下一步还原焙烧?磁选富集镍.

关键词: 红土镍矿, 硫酸钠, 热解, 动力学, TG-MS

Abstract: The thermal decomposition of Na2SO4 and nickel laterite was investigated by thermogravimetry coupled with mass spectrometer (TG?MS) and X-ray diffraction (XRD). The evolution of the thermal decomposition gas composition was detected by mass spectrometry. The results indicated that the thermal decomposition process of Na2SO4/nickel laterite can be divided into five stages: the evaporated of the free water (37~152℃), the dehydroxylation of the goethite (238~278℃), the dehydroxylation of the lizardite and kaolinite (554~602℃), the dolomite decomposition (892~914℃) and the decomposition of Na2SO4 (1241~1286℃). The main volatile products of the pyrolysis are H2O, CO2 and SO2. According to the Coasts model, the decomposition of nickel laterite with Na2SO4 can be described by one first-order reaction. The mechanism of Na2SO4/nickel laterite thermal decomposition may be Na+ replaced Ni2+, which is an isomorphic host in the lattice of (Ni,Mg)2SiO4. Ni2+ was released and reacted with O2? to form NiO, which facilitated nickel enrichment through the process of reduction roast-low intensity magnetic separation.

Key words: nickel laterite, Na2SO4, pyrolysis, kinetics, TG-MS