撞击流-旋转填料床(IS-RPB)制备纳米硫化亚铁的研究

Preparation of ferrous sulfide nanoparticles in impinging stream-rotating packed bed

为解决传统间歇式搅拌反应釜制备硫化亚铁产物粒径大、分布不均匀和重复性差的问题,以FeSO_(4)·7H2O和Na_(2)S·9H_(2)O为原料,在超重力反应器(撞击流-旋转填料床)中成功连续制备了粒径小且均一的硫化亚铁纳米粒子。利用扫描电镜、X射线衍射和激光粒度仪等方法对样品的粒径分布和形貌结构进行表征,考察了反应物初始浓度、超重力因子和撞击初速对硫化亚铁粒径的影响。结果表明,随着反应物初始浓度、超重力因子以及撞击初速的增大,硫化亚铁的粒径先减小后增大,粒径分布逐渐变均匀。最佳制备工艺条件为:反应物初始浓度为0.1 mol/L,物料比为1∶1,超重力因子β=239.8,撞击初速μ=9.43 m^(3)/s。在此条件下制备的硫化亚铁纯度较高且粒径分布均匀,中位粒径D50为87 nm,90%的硫化亚铁颗粒在150 nm以下,对铬(Ⅵ)离子有较强的吸附能力,最大吸附量为196.85 mg/g。

Using FeSO_(4)·7H2O and Na_(2)S·9H_(2)O as raw materials,small and uniform particles of ferrous sulfide nanoparticles are successfully prepared continuously in a high-gravity reactor(impinging stream-rotating packed bed),which has effectively solved the problems of poor repeatability between batches large particle size and uneven sizedistribution of the product prepared by traditional batch stirred reactor.Scanning electron microscopy,X-ray diffraction and laser particle size analyzer are employed to characterize and analyze the particle size distribution and morphological structure of the samples.Effects of the initial concentration of reactants,high-gravity factor and impact muzzle velocity on the particle size of ferrous sulfide are mainly investigated.Research results show that with the increase of the initial concentration of reactants,the high-gravity factor and the impact muzzle velocity,the particle size of ferrous sulfide firstly decreases and then increases,and the particle size distribution becomes narrow gradually.The optimized preparation conditions are as follows:the initial concentration of reactants is 0.10 mol·L^(-1),the material ratio is 1∶1,the high-gravity factorβ=65.3,and the impact muzzle velocityμ=9.43 m^(3)·s^(-1).Ferrous sulfide prepared under these conditions has a high purity and a narrow particle size distribution,with a median diameter D50 of 87 nm,and 90%of ferrous sulfide particles have a size below 150 nm.It has a strong adsorption capacity for chromium(Ⅵ),and the maximum adsorption capacity can reach 196.85 mg·g^(-1).