Comparing the effects of various grinding aids in vibrating disk and ball mills

The aim of the present research work is evaluating and comparing a number of polyglycols and ethanolamines as grinding aids for production of Portland cement in both ball and vibrating disk mills at laboratory scales. For this purpose, four different compounds including triethanolamine (TEA), diethanolamine (DEA), and polyethylene glycols of two different molecular weights, i.e. 400 and 600 (PEG400, PEG600), were used and reference samples without using any admixture were also considered in both mills. All the tested compounds result in higher Blaine specific surface areas when added at the same amount of 0.06% by weight of the sample to be ground. The incraese in Blaine specific surface area can be attributed to the additive ability not only to reduce resistance to cominution, but also to prevent powder agglomeration and coating formation on internal surfaces of the mills. Among the four compounds, DEA showed the most effective grinding aid properties in both mills. This compound increases the Blaine specific surface area of the cement by 23 and 8.6% in ball and vibrating disk mills, respectively. The compound grinding aid composed of 50 wt% PEG400 and 50 wt% DEA was less effective on Blaine specific surface area than each of its components in both mills. The results also confirm much stronger effects in ball mill compared to vibrating disk mill.