The influences and selection of grinding chemicals in cement grinding circuits N. Alper Toprak ⇑ , Okay Altun, Namık Aydogan, Hakan Benzer Hacettepe University, Mining Engineering Department, 06800 Beytepe, Ankara, Turkey highlights  Industrial sampling campaigns were arranged for different grinding chemicals.  Performances of each chemical were evaluated.  The influences on milling and classification units were discussed.  Economic evaluations were performed.  A methodology on selecting the most feasible chemical was developed. article info Article history: Received 27 February 2014 Received in revised form 21 May 2014 Accepted 30 June 2014 Keywords: Cement grinding Dry grinding Grinding aids Grinding chemicals abstract Within the study, the results of the test works performed around a cement grinding circuit in order to select the most appropriate option are presented. In this context, sampling campaigns were arranged with different grinding aids and mixed products then the influences were discussed by considering the changes in production rate, equipment performance, energy consumption, cement quality and clinker saving parameters. The results implied that the production rate of the circuit and the 28-day strength of the cement could be increased by 24% and 3.5% respectively with the selection of an appropriate chem- ical. In addition, the use of chemicals may reduce the clinker consumption by 5% that is important regard- ing to CO 2 emissions. The studies concluded that triethanolamine based chemical had better performance parameters than the other types. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Cement is an important material that its consumption has been steadily increasing depending on the construction business growing all around the globe [1]. However, the manufacturing process is known as energy intense since the energy utilization is about 110– 150 kW h per tonne of cement varying with the process moderniza- tion and raw materials used [2]. Broadly, the process is composed of many sub operations including raw meal preparation and grinding, pyrometallurgical process, finish grinding. In these stages commi- nution activities account for about 30% of the total energy consump- tion, therefore attention should be drawn to optimize the circuits. Energy efficiency of a grinding circuit, whether it is wet or dry, is affected by operating and design parameters including, mill diameter, mill length, media size and filling, throughput, classifier design etc. In addition to these variables, material characteristics also have influence on the entire operation. In wet grinding appli- cations the material properties can be expressed in terms of slurry rheology that affects the performances of milling and classifying machines. Dry grinding is a challenging process regarding to the material transportation where the particles are prone to form agglomerates and coat on media as well as the mill liners owing to the static forces arising during grinding action. Mill ventilation improve the milling performance up to a certain extent but it is not sufficient to prevent the coatings. Rehbinder and Kalinkovaskaya [3] introduced chemicals that reduced the solid surface energy while the new surfaces were gen- erated following the grinding action. Klimpel and Manfroy [4] also approached the function of the chemicals in the same manner. They reported that, the surface of the particles are neutralized hence the probability of forming agglomerates and coatings is reduced that ultimately provides more efficient grinding environ- ment. In addition, the bulk material becomes fluidized and that makes the transportation along the mill easier. Today, grinding chemicals are reported as capacity improvers or in some cases strength enhancers. Cement grinding operations demand these chemicals in order to improve its energy efficiency. As it is a dry http://dx.doi.org/10.1016/j.conbuildmat.2014.06.079 0950-0618/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +90 3122977600; fax: +90 3122992155. E-mail address: natoprak@hacettepe.edu.tr (N.A. Toprak). Construction and Building Materials 68 (2014) 199–205 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat