Synthesis Of α-amino Benzyl Phosphonic Acids And Their Flotation Performance On Fluorite Ore

As a prime source of fluoride in fluorine products and a kind of important nonmetallic mineral raw material, fluorite ore is mainly used in metallurgy, steel, chemical, glass, cement, ceramics and other fields. Fluorite mineral resources is abundent in China, but there are some deficiencies, such as, low grade, fine particle and complicated composition, which can cause a lot difficulty in benefication of fluorite. Recently the method of flotation became an effective method to separate fluorite from mixed ore.Four novel fluorite collectors a-amino benzyl phosphonic acids (a-d) were synthesized. Their structures were characterized by IR spectra and1HNMR. Influence of reaction time, reaction temperature, catalyst, catalyst dosage, mole ratio of raw material on synthesis process were investigated to optimize the synthesis technique. As a result, yields of a-d were96.97%,49.74%,75.00%,84.29%, respectively.The flotation behaviors of fluorite, quartz and actual fluorite ore were studied, The recoveries of four fluorite collectors reached over80%at pH=8-10, fluorite maximum recovery rate of collector a was91.33%, while recovery rate of quartz were below10%at pH=2-12. Recoveries of a-d on actual fluorite ore were91.11%、90.71%、95.60%and89.89%, respectively. The contrast experiments between amino phosphonic acid and oleic acid, which was a traditional collector, were conducted, it was found that collector a got1.91%of recovery ratio for actual fluorite ore more than oleic acid.IR spectra and Zeta-potential were investigated, it indicated that the absorption model between amino phosphonic acid and fluorite ore could mainly be chemical adsorption, and partially physical absorption. The curves of CMC on four collectors proved collector a had better adsorbability than the other three collectors. Based on experiment data, the flotation capacity of a-d was a>c>d>b.