硫酸熟化-焙烧法从镍红土矿中回收镍和钴动力学研究

采用X线荧光(XRF)、X线衍射(XRD)、扫描电镜(SEM)等手段对镍红土矿的化学组成、物相组织、显微结构以及镍钴赋存状态进行矿物学表征.通过硫酸熟化-焙烧-水浸法从镍红土矿中提取镍和钴,并研究镍和钴在硫酸熟化-焙烧过程中的动力学.结果表明:镍和钴的硫酸化过程符合Bagdasarym提出的多相液固区域反应模型,相应的动力学方程式可以用ln(-ln(1-α)=ln k+nln t(其中,α为反应进行程度,k为反应速率常数,t为反应时间,n为矿物中晶粒性质和几何形状的函数)来表示,镍和钴的硫酸化反应表观活化能分别为21.45 kO/mol和34.81kJ/mol,动力学控制过程为内扩散控制.

Kinetics of sulfation-roasting of nickel laterite for recovery of nickel and cobalt

Mineralogical characterizations of the nickel laterite material were done by X-ray fluorescence(XRF),X-ray diffraction(XRD),scanning electron microscope(SEM) and other techniques.Nickel and cobalt were extracted from nickel laterite by sulfation-roasting-leaching process and the kinetics of nickel and cobalt sulfation was studied.The results show that the sulfation of nickel and cobalt accords with the liquid-solid regional reaction model raised by Bagdasarym and the kinetic equation is expressed as ln(?ln(1?α))=ln k+nln t(where α is reaction degree;k is reaction rate constant;t is reaction time;n is the function of property and geometric shape of particles in minerals).The activation energies are determined to be 21.45 kJ/mol for nickel and 34.81 kJ/mol for cobalt respectively,which are characteristic of an internal diffusion controlled process.