Adsorption Property Of Heavy Metal Ions On Diaspore

Metal ion is the main pollutant in soil and liquid, and pollution byheavy metals has received wide spread attention in the recent years.Nature mineral materials are proved a new way for efficiently utilizes.Diaspore is the major alumina mineral. In this paper, the studies relatingto decomposition and planetary-grinding and it's adsorptive property ofheavy metal ions were carried out. It was based on crystal chemistry andsolution chemistry with the help of atomic adsorption spectrometer,thermogravimetry, differential scanning caloritemtry, X-ray diffraction,infared spectroscopy, atomic force microscope, scaning electronmicroscope, BET surface area measurement and Zeta potentialmeasurement.It was found that the decomposition of diaspore was carried out at485℃andα-Al₂O₃ was obtained; The fast heating rate leads thedecomposition hysteresis; Activation energy of the decomposition was268.67kJ/mol by Coats-Redfem equation; The adsorption ratio of Cu²⁺and Zn²⁺ increased with the increase of colcine temperature, theadsorption got maximal at 500℃and then it decreased with the furtherheating.After planetary-grinding, the BET surface area was increased,crystal structure destroyed and the reaction activity increased; As theincrease with solution pH, the adsorption ration of Cu²⁺, Pb²⁺, Zn²⁺increased, but the adsorption ration of CrO₄^2- decreased; the adsorptionisotherms of Cu²⁺, and CrO₄^2- could be well described by the Langmuirequation; The effect of solution temperature was investigated.Chromate increased the adsorption of Cu²⁺ and Zn²⁺ on diaspore.The competitive adsorption followed the order Cu²⁺＞pb²⁺＞Zn²⁺.The distributions of heavy metal ion hydrolysate, the solubility ofdiaspore and the effects of pH value on them were analyzed by solutionchemistry calculation; the adsorption mechanism was discussed by atomforce microscope and crystal chemistry.