Determination of surface chemistry and flotation properties of rare earth mineral allanite

In this study, flotation properties of allanite, a sorosilicate rare earth mineral that commonly found in some new complex ore reserves, was studied with EDA (CH₃–(CH₂)₉–O–(CH₂)₃–NH₂/ethylenediamine), a commercial cationic collector in the etheramine acetate group, and R845N (tetrasodium N-(1,2-dicarboxyethyl-N-octadecyl/octadecenyl sulfosuccinamate), a commercial anionic collector in the alkyl succinamate group. In this context, firstly micro-flotation studies were carried out using a pure crystalline allanite specimen. In accordance with micro-flotation studies; zeta potential, contact angle, and bubble-particle attachment time measurements were also carried out to investigate the surface properties of allanite mineral. Conventional flotation experiments were also carried out under the conditions determined in the surface chemistry studies. The micro-flotation experiments showed that the flotation recovery increased up to approximately 93.00% and 48.50% at 100 ppm for EDA and R845N, respectively. A strong relationship between flotation recovery and bubble-particle attachment time were observed. The zeta potential and contact angle values of the allanite sample increased with the increasing concentrations for both collectors which indicated a successful collector adsorption onto allanite surface. Moreover, a correlation between the results of flotation recovery, contact angle and zeta potential measurements was also determined. Thus, a significant contribution was achieved in terms of understanding the micro-flotation results. The results of conventional flotation were consistent with the micro-flotation results as the ΣREE grade of the floated fractions were 0.59% and 0.99%, and the recovery rate of floating fractions were 81.39% and 64.24% for EDA and R845N, respectively. The obtained results clearly demonstrated that R845N, a collector of the alkyl succinamate class, can be used for selective separation of allanite from the other silicate gangue minerals.