The use of Dextran and flocculant with the goal of performance optimization of Kelly filters

Alumina is produced from Bauxite using the Bayer process in Iran. In this process, after the digestion step, liquor separation from red mud is accomplished. Separation is done in the thickeners. To remove the suspended solids, Kelly filters are used. The more the amount of suspended solids, the more pollution and less efficiency occurs. In this research, for decreasing the bad effects, a type of flocculant and Dextran (NFO) are used. By using these reagents, suspended solids are decreased and settling process is optimized which yields the increase in clarity as well as product quality. The results indicate that by using Dextran we can decrease the amount of suspended solids from 520 ppm to 112 ppm.the results also show that at the same flocculant dosage, the treatment with red mud by (SNF99) gives a faster red mud settling rate.

کلیدواژه ها:

alumina ، red mud ، flocculant ، settlement ، clarificati on