The effect of foreign ions on the reactivity of the CaO–SiO2–Al2O3–Fe2O3 system

Effect of sulfur on the polymorphism and reactivity of dicalcium silicate of Portland clinker

“…Samples were ground down to > 0.045 mm and their grain-size was controlled by sieving. An amount of 5 g of each sample was mixed in distilled water in a water/sample mass ratio of 0.4 and stored at 40 o C for 80 h to achieve full hydration and formation of portlandite (Ca(OH) 2 ) and hydrated calcium silicates (CSH). After hydration, samples were milled and dried at 200 o C for 24 h. An 8 mg aliquot from each sample was used for DSC analysis.…”

“…The sources of sulfur in the context of cement production are raw materials and fuels, particularly pet coke, in which the sulfur content may reach up to 6wt.% [1]. Sulfur may be present in the raw materials as sulfi des, mainly the iron sulfi de pyrite, which is likely to increase sulfur emmissions, since sulfur volatility largely depends on its oxidation state, and sulfi des are considered to be more volatile than sulfates [2]. Among the main crystalline phases of clinker, dicalcium silicate (Ca 2 SiO 4 ) has the higher capacity of sulfur incorporation [3].…”

Opportunities for Energy Efficiency and Demand Response in the California Cement Industry

“…These systems not only save fuel, but increase throughput and refractory life of the kiln (Worrell and Galitsky). If a plant's raw mix has low burnability, the addition of mineralizers can reduce the kiln temperature needed for clinkering, saving fuel (Kolovos et al, 2001). The most efficient clinker coolers are able to achieve heat recovery efficiency of up to 80%, reducing the amount of fuel which must be burned in the kiln.…”

Efecto del ZnO, ZrO₂ y B₂O₃ en el proceso de clinkerización. Parte I. Reacciones de clinkerizacion y composición de los clínkeres

“…Estos componentes minoritarios influyen en los procesos reactivos, en las fases mineraló-gicas del clinker y en las propiedades finales del cemento. Asimismo durante las reacciones de clinkerización los componentes minoritarios pueden actuar disminuyendo la temperatura de formación de la fase líquida y aumentando su contenido comportándose dichos componentes como fundentes, alterando la viscosidad y la tensión superficial del fundido, afectando ambas propiedades, a la velocidad de las reacciones actuando éstos como mineralizadores y al crecimiento y morfología de los cristales (1,2). Los componentes minoritarios pueden quedar fijados en una proporción limitada en las fases mineralógicas del clinker.…”

“…Such minority components affect reactive processes, the mineral phases of the clinker and cement properties. Similarly, during clinkerization reactions the minority components may act as fluxes, lowering the temperature at which the molten phase forms and increasing its content, or as mineralizers, altering the viscosity and surface tension of the molten mass as well as crystal growth and morphology (1,2). Part of the minority components may be fixed in the mineral phases of the clinker.…”