Theoretical Research Of The Adsorption Mechanism,the Synthesis And The Application Of The Carboxyl Hydroxamic Acids

Molecular methods、quantum chemistry and flotation test are used to study the flotation reagents BHOM、BHDM and BHDDM and the flotation mechanism of compounds.The structures of collector agents like BHOM、BHDM and BHDDM are as follows:non-polar groups with8、10and12carbons chain length, polar groups with double hydroxamic and double carboxylic. The synthetic routes of three molecules was design with diethyl malonate, bromide succinate sodium as raw materials. The results of flotation experiments for the single minerals showed that by using these compounds as collectors, the pulp pH value has significant influence on their collecting performance as the floatability of diaspore varies sharply with their change. The appropriate pH value for the flotation of diaspore gets close to neutral condition at which diaspore presents good floatability while kaolinite and illite exhibit poor floatabilities. The flotation recovery of BHOM and BHDM with2×10-4mol/L is near99%around pH7.The character of the three molecules was discussed by means of density functional theory (DFT) at the level of B3LYP with the6-31G*basis set; calculated the Molecular frontier orbital energy, Charge distribution, The delocalization situation, and Energy gap△E; thus this paper investigated the structure-activity relationships between this kind of carboxyl hydroxamic acids and flotation. It was found that molecules active atoms were the N and O atoms on the base of the polar groups because of the ability to provide electrons. The more number non-polar groups in molecules, the less lively.Molecular dynamics simulations were performed to model the combinative progress of carboxyl hydroxamic acids on diaspore (010), kaolinite(001) and illite (001) by discover module, then binding energy, nonbond interaction energy, deformation energy and pair correlation function were obtained to discuss the interaction and flotation mechanism. The results show that the oxygen atoms of the hydroxamic acid have a strong hydrogen bonding with the diaspore mineral crystal, and hydrogen bonds for kaolinite.