Effect of some Grinding Aids on The Fineness and Hydration Characteristics of Portland Cement inPresence and Absence of Limestone

Abstract

Grinding aids are organic substances that are strongly adsorbed on the surface of ground particles, so that preventing agglomeration and coating on ball and mill lining. The main purposes for their addition are increasing the grindability of the cement clinker and therefore reduce the energy required to grind the clinker into a given fineness. As a consequence the presence of grinding aids increases the efficiency of the cement mill. Grinding aids have been used for more than 50 years and the most common additives can be divided into groups according to their structure as glycols, alcohols, amines and phenol type compounds.

In addition to increase the efficiency of the mill, some grinding aids also provide important positive effects on the final cement such as increasing rheology of the fresh cement paste or concrete and improvement of the strength development. Grinding aids that provides these properties are called “quality improvers” or “performance enhancer. The addition of grinding aids to the clinker during cement production is indeed important for several reasons. Firstly, fineness (Blaine) of the finished