Study On Utilization Of Tailings Backwater From Bauxite Flotation

In order to recycle the backwater from tailing slurry of bauxite floatation, some research about tailing slurry's settling and backwater's influence on floatation has been done in this thesis, expected to find one flocculant to utilising backwater efficiently.Experiments of tailing slurry's settling show:flocculant based on physical absorption is hard to achieve a good performance, and anion organic flocculant based on chemisorption can always get a better result because the force between flocculant and particle is very strong;among several kinds of anion organic flocculant, HMX03117 with the group of-COONa achieves the best performance, and the settling result is pretty good with a appropriate dosage of 110g/t;When pH=7, tailing slurry attains the best settling performance, otherwise slurry will be awash with extra negative charges or positive charges; The concentration of tailing slurry shouldn't be high and is reasonable at 3.3%, otherwise distance between particles will be shorten and repelling interaction will be sharpen, which make settlement slowly; Slowly stirring is beneficial to the settlement of slurry, but fast stirring is against the settlement of slurry because it will break up the long molecular chains belong to flocculant into several small pieces.Experiments of backwater's influence on floatation show:backwater form tailing slurry reservoir is available to utilise in the process of floatation, but returning proportion must be controlled within 40%-60%, on the other hand, returning proportion of backwater produced by HMX03117 is high up to 80%; residual amount of HMX03117 in the bacwater shouldn't exceed 0.005g/1, which is 45 gram per ton of feeding ore, and surpassing this amount will cause notable decrease of technical index;when the dosage of HMX03117 is at 110g/t, which is 28g/t in terms of feeding ore, which is less than 45g/t, so this will have little influence on floatation at this dosage;Na+ existed in the backwater has little influence on the floatation; Fe3+ existed in the backwater has a little influence on the floatation, mainly because many tiny ferric hydroxide precipitations cap mineral surface, as a result, technical index drop; Al3+ existed in the backwater has a similar influence, but the difference is tiny aluminum hydroxide precipitations cap mineral surface disorderly and this increases adsorption sites between particle and collector, consequently the grade of concentrate drop; If the proportion of backwater is controlled between 40% and 60%, metal ion content in the water will be diluted by half and the effect on floatation is very low.