Electrokinetics and flotation of diaspore in solutions of different alkylamine hydrochlorides (with 12,14 and 16 carbon atoms) were studied. The point of zero charge (PZC) of diaspore was determined by measuring zeta ...Electrokinetics and flotation of diaspore in solutions of different alkylamine hydrochlorides (with 12,14 and 16 carbon atoms) were studied. The point of zero charge (PZC) of diaspore was determined by measuring zeta potential (streaming potential method) as a function of pH. Dodecyl , tetradecyl and hexadecylamine hydrochloride ions seem to be strongly adsorbed on the interface because they make the zeta potential more positive as the concentration increases. The PZC of diaspore is determined at pH 5.7. Flotation of diaspore was studied and shown to be influenced by the chain length of collectors and both collector and hydrogen ion concentration. The optimal experimental flotation conditions as pH and concentrations agreed well with that predicted from solution chemistry calculations, and the floatability of diaspore is poor while the pH value of flotation system is too high or low. The results of calculation also predict a wide pH range of effective flotation with increasing collector concentration.[展开更多
A novel, convenient and efficient approach to the synthesis of pyrrole and imidazole derivatives via the reaction between primary amines, alkyl propiolates or isothiocyanate and oxalyl chloride is described. The metho...A novel, convenient and efficient approach to the synthesis of pyrrole and imidazole derivatives via the reaction between primary amines, alkyl propiolates or isothiocyanate and oxalyl chloride is described. The method offers several advantages including high yields of products and performing reaction under solvent-free conditions.展开更多
文摘Electrokinetics and flotation of diaspore in solutions of different alkylamine hydrochlorides (with 12,14 and 16 carbon atoms) were studied. The point of zero charge (PZC) of diaspore was determined by measuring zeta potential (streaming potential method) as a function of pH. Dodecyl , tetradecyl and hexadecylamine hydrochloride ions seem to be strongly adsorbed on the interface because they make the zeta potential more positive as the concentration increases. The PZC of diaspore is determined at pH 5.7. Flotation of diaspore was studied and shown to be influenced by the chain length of collectors and both collector and hydrogen ion concentration. The optimal experimental flotation conditions as pH and concentrations agreed well with that predicted from solution chemistry calculations, and the floatability of diaspore is poor while the pH value of flotation system is too high or low. The results of calculation also predict a wide pH range of effective flotation with increasing collector concentration.[
文摘A novel, convenient and efficient approach to the synthesis of pyrrole and imidazole derivatives via the reaction between primary amines, alkyl propiolates or isothiocyanate and oxalyl chloride is described. The method offers several advantages including high yields of products and performing reaction under solvent-free conditions.
