Study On Phase Transfer Catalytic Synthesis Of Alkyl-malonic Acid And Applications Of Flotation

Collectors play an critical role in metal mineral flotation process. Research and development of oxide mineral collector with excellent selectivity, less environmental pollution and cheap price characteristics have been imminent and imperative. In this work, a new chelating collector type of alkyl-malonic acid was synthesized and floatation process for as-produced collector was investigated.The benzyl malonic acid was synthesized with benzyl chloride, diethyl malonate , anhydrous potassium carbonate and phase transfer catalyst PEG-400 by chemical phase transfer catalytic method. Earlier period synthesis process of benzyl malonic acid was performed by microwave method. The effects of phase transfer catalyst type, content, proportions of raw material, reaction temperature, reaction time and hydrolysis conditions on reaction were investigated, respectively. The results show that the optimum condition of benzyl malonic acid synthesis is phase transfer catalytic method. Product yield of the diethyl benzylmalonate can reaches 75.84 % when phase transfer catalyst is PEG-400, reaction temperature is 160℃and reaction time is 2.0 h. White needle crystal benzyl malonic acid synthesized by diethyl benzylmalonate hydrolyzation was analyzed using FT-IR, 1H-NMR. The flotation research of oxidation lead mine with benzyl malonic acid as chelate collector show that column flotion can give lead concentrates of high grade 48.26% at a recovery as high as 73.06%.1-octyl-malonic acid and 1-dodecane-malonic acid were synthesized with 1-bromooctane, 1-bromo-dodecan, and anhydrous potassium carbonate by chemical phase transfer catalytic method, respectively. Earlier period synthesis process of 1-octyl-malonic acid was performed by microwave method. The effects of phase transfer catalyst type on reaction were investigated by chemical method. The results show product yield of 1-octyl-malonic can reaches 64.56 % when phase transfer catalyst is PEG-400 and product yield of 1-dodecane-malonic can reaches 63.45 % when phase transfer catalyst is TBAB. FT-IR and 1H-NMR spectra of as-produced indicate that 1-octyl-malonic and 1-dodecane-malonic are synthesized. The flotation research of oxidation lead mine with 1-octyl-malonic acid as chelate collector show that column flotion can give lead concentrates of high grade 47.23% at a recovery as high as 59.51%. The flotation research of oxidation lead mine with 1-dodecane-malonic acid as chelate collector show that column flotion can give lead concentrates of high grade 31.45% at a recovery as high as 46.28 %.