Study On The Mechanism Of Composite Collector In The Flotation Of Monazite

Rare earth minerals have complex mineralogy,and.the reagent compounding is an important approach for effective separation.This paper study the effect and mechanism of octyl hydroxamic acid combined with fatty alcohol and neutral oil on the flotation of fine-grained monazite.Firstly,the optimum flotation condition?pH=9,collector amount 0.24 mmol/L?was calculated for monazite flotation with octyl-hydroxamic acid as collector at different pH values.Octyl-hydroxamic acid was compounded with variety fatty alcohols in different ratios,including n-octanol,2-Ethylhexanol,n-decyl alcohol,terpineol,n-dodecyl alcohol and n-tetradecyl alcohol.Similarly,octyl hydroxamic acid was compound with neutral oils,including n-octane and n-decane,N-dodecane,n-tetradecane.Flotation tests on micro-grained monazite were conducted using those compounded reagents.The experimental results verified the effectiveness of the compounded reagents.Among the fatty acids,n-dodecyl alcohol performed well with octyl hydroxamic acid?1:1?,increasing recovery by 31%and 15.5%for-38⁺15?m and-15?m size interval respectively.Among the neutral oils,n-dodecyl alcohol performed well with octyl hydroxamic acid?1:1?,increasing recovery 28%and 32.5%for the size interval respectively.With the same length of carbon chain,the neutral oils had slight advantage over the fatty acidsDuring the flotation tests,the mechanism of adsorption of the compounded reagents onto monazite was detected by infrared spectroscopy?FTIR?,Zeta potential and solution chemistry calculations.It was found that-C=O-Ce-ON-occurred by octyl hydroxamic acid reacting with Ce³⁺on the interface,and space left were occupied by n-dodecyl alcohol and n-tetradecane,which improve hydrophobicity coordinately.The paper presents an optimum reagents combination and its mechanics,which may benefit the development of novel compounded reagents.