Use of Boron Compounds as Grinding Aids with Alcohol Amines and Their Effect on Portland Cement Setting Points

Abstract

Milling aids have been predominantly developed to increase the performance or grinding capacity of cement products, and alcohol amines have been used as grinding aids in cement grinding processes for many years. Moreover, the setting point of cement produced with grinding aids is most often changed. In this study, the effects of alkanolamines and boron compounds in different mixing amounts as grinding aids on the set point of cement were researched. Triethanolamine (TEA) and triisopropanolamine (TIPA) were used as alkanolamines and boric acid (BA) and anhydrous borax (AHB) as the boron compounds. It is evident that BA with TEA had a small effect on the cement setting point where the former decreased the retarding effect of the latter, but BA had no effect with TIPA. AHB decreased the retarding effect of TEA but had no effect with TIPA on setting times. When the boron compounds were added to TEA, they accelerated the initial setting points of cement by 15 to 20 minutes and the final setting points by 25 to 30 minutes according to the amount of TEA used.

Effects of Triisopropanolamine and Triethanolamine on Some Properties of Portland Cement

“…Cement strength enhancing has been researched at almost every stage from manufacturing process to using process of Portland cement. Using additives for enhancing early strength of Portland cement is regarded as a good solution [3][4][5][6][7][8][9][10]. There are many additives are used in the manufacture of cement with various targets, in which, there are 3 main types: processing admixture, mineral additives, and mineralization admixture.…”

“…The popular processing admixtures used in cement technology are triethanolamine (TEA) and triisopropanolamine (TIPA) [4][5][6]. Alkanolamines are amines containing a single, double, or triple hydroxyalkyl group, which are frequently used as concrete admixtures and grinding aids additives [7]. TEA and TIPA are known as 2 organic grinding aids.…”

“…They can absorb the surface of particles, create a film separating particles, reduce the free energy of the surface of the system. On the other hand, they also change the suction force of Van der Waal, increase the thrust, thereby improve the crushing efficiency [3,[5][6][7].…”

“…There is some evidence for the formation of a complex surface between C3S, C2S initial hydrate and TEA. [7].…”

“…The addition of small amounts of TIPA can result in a significant increase in the strength of cement pastes at early and late ages [7,11]. The strength at the early ages (1 day and 3 days) of cement prepared with TEA increases, but at the age of 28 days the strength decreases.…”