The influence of Triethanol amine and ethylene glycol on the grindability, setting and hydration characteristics of Portland cement

Abstract

Triethanol amine and ethylene glycol are used as grinding aids for Ordinary Portland Cement (OPC). Standard water of consistency, Blaine area, initial and final setting times and compressive strength are tested for OPC. The phase composition and microstructure of the formed hydrates are tested using DTA/TG and SEM techniques. Results showed that both the two GAs had a significant improvement in the performance of grinding mills. This is indicating by higher Blaine area when a dose of 0.03, 0.04 and 0.05wt. % are applied. Beside there are increase in the water demand (greater than 5%) for the all OPC mortar mixes admixed with triethanol amin or ethylene glycol at concentrations less than 0.05 wt.%. The improved hydration properties are reflected by an increase in the mechanical properties and microstructure of the mortar pastes admixed with the two GAs. This is with attributed to the increase in the cement fineness which leads to the progress in the degree of cement hydration.

Quantifying the effect of the grinding aids in a batch stirred mill by a modelling approach

“…Following that, the tests were carried out at various dosages with two different types of grinding aids. Grinding aids can be classified into three types based on their structure: aliphatic aminebased, glycols-based and phenol-based (Hashem et al, 2019) The amine group Triethanolamine (TEA) and glycol group Ethylene glycol (EG) are used in this study (as given in Table 2).…”

“…The absence of any change in the grinding index values indicates the presence of this formation. Grinding aids, which tend to form multimolecular layers, should be used with caution as they can create capillary forces that favor agglomeration (Hashem et al, 2019).…”

“…They are categorized into three groups based on their structure: aliphatic amines-base, glycols-base and phenol-base. The high polarity of their chemical functioning groups reduces the surface energy forces, which cause agglomeration of the newly produced particles (Jeknavorian et al, 1998, Hashem et al, 2019 Most of the time, different grinding aids with varying dosages are tested in laboratory conditions by trial and error. A simple methodology is required to compare the results of different grinding aids and dosages in batch milling.…”

Monoethanolamine Oxypropylation Kinetics

“…Третичные аминоспирты (триэтаноламин, триизопропаноламин) находят широкое применение в качестве интенсификаторов помола цемента, позволяющих не только снизить энергозатраты при производстве, но также и повысить качество получаемого продукта [1][2][3][4][5]. Например, третичные аминоспирты проявляют различное действие на цементные пасты в зависимости от собственной структуры, дозировки и типа цемента.…”

“…Оксипропилирование МЭА по гидроксильной группе, а также образование амина 2в протекают в незначительной степени, содержание соответствующих продуктов в реакционной смеси составляет менее 0,05% мас. В связи с этим, в кинетической модели изучаемого процесса рассматривались только реакции (1)(2)(3)(4)(5). Математическая модель превращений описывается системой из четырех дифференциальных кинетических уравнений второго порядка и уравнения материального баланса.…”