Selective flocculation of iron oxide-kaolin mixtures using a modified polyacrylamide flocculant

Abstract

High molecular weight polyacrylamides were synthesized and successfully modified to contain up to 8.3% hydroxamate functional groups. The selective flocculation tests carried out on I : 1 iron oxide/kaolin mixtures using parent polyacrylamide, polyacrylic acid and the modified polyacrylamide, confirm the possibility of enhancing selectivity through introduction of iron chelating functional groups in commercially available polymers. Starting with a feed grade of 35% iron, 92% recovery with acceptable grade of 60% iron has been achieved using the modified polyacrylamide.

Role of hydrolyzable metal cations in starch–kaolinite interactions

“…In the literature, flotation and selective flocculation have both been investigated for the removal of alumina containing minerals from iron ore (Gururaj et al, 1983;Ravishankar et al, 1988;Mahiuddin et al, 1989;Pradip et al, 1993;Ravishankar et al, 1995;Weissenborn et al, 1995;Ma et al, 2009;Ma and Bruckard, 2010).…”

The effect of pH and ionic strength on starch–kaolinite interactions

“…The selective adsorption of starch onto hematite instead of the gangue minerals is of critical importance not only for the flotation of iron ore, but also for the selective flocculation of iron ore as well, since starch appears to be more selective than other flocculants such as polyacrylamides and polyacrylic acid (Weissenborn et al, 1994;Ravishankar et al, 1995). In the literature, flotation and selective flocculation have both been investigated for the removal of alumina containing minerals from iron ore (Gururaj et al, 1983;Ravishankar et al, 1988;Mahiuddin et al, 1989;Pradip et al, 1993;Ravishankar et al, 1995;Weissenborn et al, 1995;Ma et al, 2009). However, the adsorption behaviour of starch on alumina containing minerals, the role of steric forces in the system of starch and alumina containing minerals, and the effect of pH and ionic strength remain unknown.…”

Separation of aluminium and preparation of powdered DRI from lateritic iron ore based on direct reduction process

“…Physical methods can be classified into three categories: gravity separation, magnetic separation and flotation separation. Gravity separation is the most frequently used method, involving hydrocyclone classification, 8,10,11 dispersion-flocculation, [12][13][14][15][16][17] jigging, 18,19 and teetered bed gravity separation, 20 enhanced gravity separation, 7 multi-gravity separation. 21 Magnetic separation includes high intensity magnetic separation, 22,23 high gradient magnetic separation 24 and selective magnetic coating.…”