褐铁型红土镍矿硫酸熟化过程及其机制研究  

Process and Mechanism Study on Activation Pretreatment of Limonitic Laterite Ores at Low Temperature

作　　者：马保中[1,2] 金炳界[1] 裴彦林 杨玮娇[1,2] 魏永刚[1] 王成彦[1,3] Ma Baozhong Jin Bingjie Pei Yanlin Yang Weijiao Wei Yonggang Wang Chengyan(State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, China Beijing General Research Institute of Mining and Metallurgy, Beijing 100160, China Institute of Metallurgical and Ecological Engineering, Beifing University of Science and Technology, Beijing 100083, China)

机构地区：[1]昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室,云南昆明650093 [2]北京矿冶研究总院,北京100160 [3]北京科技大学冶金与生态工程学院,北京100083

出　　处：《稀有金属》2017年第10期1159-1166,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金青年基金项目(51304023);国家自然科学基金面上项目(51274044);国家自然科学基金云南省联合基金项目(U1302274)资助

摘　　要：以褐铁型红土镍矿为原料,研究了其硫酸熟化过程及其矿物物相转变机制。考察了熟化过程中温度、时间、硫酸量、加水量对熟化过程的影响,结果表明:Ni,Co浸出率随熟化温度的升高、硫酸用量的增加、熟化时间的延长而提高,一定的加水量有利于Ni,Co的浸出。熟化最佳工艺条件为:温度450℃、硫酸量为每吨矿500 kg、时间60 min、加水量20%,在该条件下,Ni,Co和Fe的浸出率分别为78.1%,91.1%和9.6%。采用热重-差示扫描量热法(TG-DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)对硫酸熟化过程矿物物相转变机制进行了研究,结果表明:200℃下熟化,矿相未被破坏,以针铁矿(FeOOH)为主;250℃时,部分FeOOH转变为赤铁矿(Fe_2O_3)和不溶性的碱式硫酸铁(Fe(OH)SO_4);300~350℃时,矿物结构被有效破坏,绝大部分FeOOH转变为Fe_2O_3;升温到400℃,Fe(OH)SO_4分解为Fe_2O_3;450℃时,完全可见Fe_2O_3且其结晶度最好;500℃时,Fe(OH)SO_4转变为硫酸铁(Fe_2(SO_4)_3),但仍以Fe_2O_3为主。大部分Ni,Co矿物转化为可溶性硫酸盐,少量转变为不溶性的铁酸镍(NiFe_2O_4)、铁酸钴(CoFe_2O_4),造成Ni,Co的损失。The pretreatment process of limonitic laterite ores at low temperature and the mineral phase transformation mechanism were studied. The effects of temperature,duration,sulfuric acid and water addition on the activation pretreatment were investigated. The results showed that the extractions of Ni and Co increased with the increase of temperature,acid addition and duration,and adding a certain amount of water was beneficial to the extraction of Ni and Co. The optimal activation pretreatment conditions were as follows： the temperature was 450 ℃,the amount of sulfuric acid addition was 500 kg per ton of ore,the duration was 60 min and the water addition was 20%. Under these conditions,the extraction of Ni,Co and Fe were 78. 1%,91. 1% and 9. 6%,respectively. Thermogravimetry and differential scanning calorimetry（ TG-DSC）,X-ray diffraction（ XRD）,scanning electron microscope（ SEM）,energy dispersive spectrometer（ EDS） were utilized to explore the mechanism of mineral phase transformation during the activation pretreatment process at low temperature. The results suggested that mineral phase transformation could not be completed below 200 ℃,and the main phase was goethite（ FeOOH）. FeOOH could partly transform into hematite（ Fe2O3） and insoluble ferric subsulfate（ Fe（ OH） SO4） at 250℃. Mineral phase could be effectively transformed at the temperature range of 300 - 350 ℃,and the majority of FeOOH could transform into Fe2O3. Fe（ OH） SO4 transformed into Fe2O3 when the temperature reached 400 ℃. Fe2O3 with good crystallinity was the dominant mineral phase at the temperature of 450 ℃,and Fe2O3 was still dominant phase at 500 ℃,while Fe（ OH） SO4 transformed into ferric sulfate（ Fe2（ SO4）3）. The majority of Ni-and Co-bearing minerals could transform into soluble sulphates,and the minority transformed into insoluble nickel ferrite（ NiFe2O4） and cobalt ferrite（ CoFe2O4） which resulted in the loss of Ni and Co.

关 键 词：褐铁型红土镍矿 硫酸熟化 矿相转变 

分 类 号：TF19[冶金工程—冶金物理化学] TF815