Minerals flotation properties study

Of all the lead oxide minerals, cerussite and anglesite [1,2] have been studied the most. The flotation properties of cerussite and anglesite are different in such a way as the anglesite is less amenable to sulphidization than cerussite. The sulphidization process for both minerals is a delicate process and is sensitive to (a) level of additions of sulphidizer, (b) the number of sulphidization stages and (c) conditioning time with sulphidizer. 

Many processes involving carbonates - ubiquitous minerals in natural systems -are controlled by their surface properties. In particular, flotation studies on calcite have revealed the presence of a pH-variable charge and of a point of zero charge (Somasundaran and Agar, 1967). Furthermore, electrokinetic measurements have shown that Ca2+ is a charge (potential) determining cation of calcite. (Thompson and Pownall, 1989). 

Oxides and sulfides with tetrahedrally coordinated cations such as those with the zincblende structure may undergo substantial surface reconstruction. There are consequently also substantial changes in electronic structure. Much of the work undertaken on surface characterization of oxides and sulfides has been concerned with materials of importance in semiconductors and catalysts, but a certain amount of work has also been prompted by the importance of surface studies in mineral technology. Examples include studies of the surface properties of chalcopyrite (Buckley and Woods, 1984), galena (Tossell and Vaughan, 1987), or pyrite during extraction by flotation (Brion et al., 1980). 

Ab initio methods solve the molecular Schrodinger equation associated with the molecular Hamiltonian based on different quantum-chemical methodologies that are derived directly from theoretical principles without inclusion of any empirical or semiempirical parameters in the equations. Though rigorously defined on first principles (quantum theory), the solutions from ab initio methods are obtained within an error margin that is qualitatively known beforehand thus all the solutions are approximate to some extent. Due to the expensive computational cost, ab initio methods are rarely used directly to study the physicochemical properties of flotation systems in mineral processing, but their application in developing force fields for molecular mechanics (MM) and MD simulation has been extensively documented. (Cacelli et al. 2004 Cho et al. 2002 Kamiya et al. 

Soluble salt flotation occurs in saturated solution in which the salt crystal surface is in dynamic balance between crystallization and dissolution, making it difficult to examine the interfacial properties using traditional experimental measures. In this regard, the water structure at selected alkali halide salt surfaces has been studied using MD simulation. Equilibrium surface charge signs for these salt minerals in saturated solution have been calculated by considering the ion hydration and water dipole distribution at salt-saturated brine interfaces, and the results are compared with... 

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