Evaluation of Carbon Nanotubes and Polyacrylamide Binders for Cold Agglomeration in Iron Ore Sintering with High Proportions of Ultrafine Particles

Abstract

The influence of polyacrylamide and multi-wall carbon nanotubes as binders for the granulation process for iron ore sintering was investigated in conditions of high proportions of ultrafine (< 0.150 mm). The binders were added to the sintering mixtures composed of 20 and 40 wt.% pellet feed and then subjected to granulation tests in an HPS laboratory scale route. The granules obtained were analyzed by particle size, shatter test (degradation), and cold permeability after granulation, degradation, and drying. A decrease in the granules’ size with the addition of polyacrylamide was observed due to decreased granulation efficiency, leading to low cold permeability of the granules. Adding nanotubes dispersed in burnt lime resulted in the improvement of the granulation process, presenting larger, more resistant and more permeable (before/after degradation) granules. After drying, the bed permeability of granules produced using polyacrylamide or nanotubes decreased significantly, pointing to low performance in the sintering dry zone.

Keywords

• iron ore sintering
• granulation process
• ultrafine
• binders
• polyacrylamide
• carbon nanotubes