Flocculation and Sedimentation of Bauxite Flotation Tailings

Flocculation and sedimentation of fine bauxite from flotation tailing pulp were studied using different flocculants to investigate the possibility of its application. The results of this investigation indicate that inorganic flocculants of PAC and PAS have better flocculating effect than organic flocculants of PAM1# and PAM2# when keeping the original pH (7.5~8.0) of tailing pulp, however its consumption are large. It was found that the pH of pulp is important to the tailings settlement. The dosage of flocculants are greatly reduced and the velocity of floc settling is accelerated when the pH of tailing pulp is adjusted to 6.5~7.0 using sulfuric acid. PAM1# and PAM2# are effective flocculants for fine bauxite from the tailings pulp and improved the sedimentation performance compared with PAC and PAS at pH 6.5~7.0. It was also found that the flocculants can be used in combination to treat original bauxite tailing, and good sedimentation effect has been achieved, but the dosage of reagents is bigger when the organic flocculant is combined with inorganic flocculant.

The Study of Red Mud Addition Influences in Metakaolinite-Based Geopolymer Characteristics

Bauxite tailing waste or commonly known as red mud is considered to be a very hazardous material. The using of red mud to make alternative building material has been widely studied for many years. Geopolymer as one of the breakthrough in the searching of ordinary portland cement/concrete substitution provides many options and possibilities of using different types of pozzolanic or alumina-silica materials. In this study, the using of red mud in metakaoline-based geopolymer paste has been studied in three different curing conditions for 7 days of sample age. Each sample then characterized both, macroscopically and microscopically including compressive strength testing, SEM photograph, XRD and FTIR spectroscopy

Preparation of Porous Catalyst Support with Gangue of Bauxite Tailing

Porous catalyst support was prepared using gangue of bauxite tailing which was a solid waste material. It was found that the mass ratio of gangue of bauxite and knar clay was 4: 1. The masses of cellulose and water were individually 1 wt% and 25 wt% of the total mass of gangue of bauxite tailing and knar clay. The pore forming agent M was optimum among the selected pore forming agents. The pore forming agent M didn’t residue in support after sintering so that the support wasn’t polluted. The appropriate addition of the pore forming agent M was 4%, and the catalyst support with the porosity of 41.3% was preparated. The appropriate sintering temperature and holding time were 1250 °C and 2.0 h, respectively. Mullite and quartz were the main mineral phase of the porous catalyst support and the catalyst support have good chemical stability and heat-resisting property.