石膏晶体体相与(010)表面特性的第一性原理研究OA

Phosphogypsum is a typical bulk industrial solid waste.Promoting its high-value utilization is an impor-tant measure to practice green development concept,and flotation is one of the key ways to achieve phosphogypsum purification.In order to deeply understand the flotation behavior of phosphogypsum and guide the development of flo-tation reagents,this paper uses the first-principles of density functional theory as the calculation framework,and uses the CASTEP module in Materials Studio software to construct a model to systematically analyze the electronic proper-ties of gypsum crystals,including band structure,density of states distribution and charge distribution characteristics.The results show that the gypsum has insulation properties,and the surface Ca atom is a positive active site and the O atom is a negative active site.The 2p orbital of the O atom is the main contributor to the high-energy electrons near the Fermi level.It can be inferred that the O atom has the strongest reactivity and is the most likely core surface site in the flotation process.The layout value of Ca-O bond is low,showing significant ionic characteristics,which makes the chemical bond relatively easier to break.By optimizing the cell cutting parameters,the minimum surface energy of gypsum crystal(010)crystal plane is 0.354 77 J/m2.Combined with the genetic characteristics of minerals,it can be known from theoretical prediction that anionic collectors containing functional groups such as-COO-and-SO3-are easy to react with Ca sites.Cationic groups in cationic collectors(such as amines)can directly interact with highly active atoms.The flotation test results show that both sodium oleate(anionic type)and dodecylamine acetate(cationic type)have good collecting effect on phosphogypsum.In this paper,the gypsum crystal and its surface structure cha-racteristics are systematically clarified from the atomic and electronic levels,which provides a key theoretical support for deepening the understanding of phosphogypsum flotation mechanism and developing efficient targeted flotation rea-gents.