1 2018年4月
过程与工艺
过程工程学报
The Chinese Jourmal of Process Engineering
Vol.18 No.2 Apr.2018
D0I: 10.12034/j.issn.1009-606X.217279
红土镍矿与硫酸钠共热解动力学及其机理分析杨，刘守军1，史鹏政2，杜文广1，上官炬”，赵艳平2
(1.太原理工大学化学化工学院，山西太原030024：2.太原科现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)
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.结摘
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(37~152C)、针铁矿分解脱羟基阶段(238~278C)、利蛇纹石和高岭土脱羟基阶段(554~602C)、白云石分解阶段(892~914C)和Na2SO4分解阶段(1241~1286C).H20,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NazSO4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：热重-质谱联用
中图分类号：TF815
文献标识码：A
文章编号：1009-606X(2018)02-0369-06
ThermalDecompositionKinetics and Mechanism of Sodium SulfatewithNickel LateriteOres
Song YANG',Shoujun LIU',Pengzheng SHI,Wenguang DU',Ju SHANGGUAN3,Yanping ZHAO2(I. 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) sae spectrometer (TGMS) 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 NazSOs/nickel laterite can be divided into five stages: the evaporated of the free water (37~152 °C), the dehydroxylation of the goethite (238~278 'C), the dchydroxylation of the lizardite and kaolinite (554~602 °C), the dolomite decomposition (892~914 °C) and the decomposition of NazSO4 (1241~1286 °C). The main volatile products of the pyrolysis are H2O, CO2 and SO2. According to the Coasts model, the decomposition of nickel laterite with NazSO4 can be described by one first-order reaction, The mechanism of NazSO4/nickel laterite thermal decomposition may be Na* replaced Ni2+, which is an isomorphic host in the lattice of (Ni,Mg):SiO4. Ni2+ was released and reacted with O2- to form NiO, which facilitated nickel eaaaa
Key words: nickel laterite; NaSO4; thermal decomposition; kinetics; thermogravimetry coupled with mass spectrometer
前言
陆基镍矿资源主要为硫化镍矿和红土镍矿，硫化镍矿由于含镍量高、加工工艺简单，成为镍资源的重要来源之一[1.2]，随着硫化镍矿资源日趋减少，储量巨大、开采容易且运输方便的红土镍矿受到越来越多关注(3.4) 与硫化镍矿相比，红土镍矿中不仅镍含量较低，且其物相构成也极为复杂，用简单的物理分选方法难以对镍高效富集[5-7]，加入添加剂对红土镍矿选择性还原焙烧-磁
收稿日期：201707-18，修回日期：2017-0824 基金项目：太原市科技计划资助项目(编号：160302)
选分离可高效富集镍[8,9],Zhu等[10]添加CaSO4，用褐煤在1100℃下直接还原红土镍矿，得到了较好的选别指标(Ni品位6%，回收率92.1%)，添加剂CaSO4在高温下分解为S,O2和CaO,CaO与FeO和SiO2反应生成钙铁橄榄石(CaFeSiO4)，影响铁氧化物还原顺序并抑制其还原速度，提高了Ni的富集率，李光辉等]对NazSO 强化红土镍矿还原的效果进行了深入研究，认为NazSO4 可提供S与铁氧化物反应生成FeS，降低镍晶粒的表面张力，促进镍铁晶粒定向聚集及长大.
0800300109-1086
Yang S, Liu S J, Shi PZ, et al. Thermal Decomposition Kinetics and Mechanism of Sodium Sulfate with Nickel Laterite Ores (in Chinese) Chin. J. Process Eng, 2018, 18(2): 369374, DOI: 10.12034/j.issn.1009-606X.217279.
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