New Types and Dosages for the Manufacture of Low-Energy Cements from Raw Materials and Industrial Waste under the Principles of the Circular Economy and Low-Carbon Economy

Abstract

The cement manufacturing industry is one of the main greenhouse gas emission producers and also consumes a large quantity of raw materials. It is essential to reduce these emissions in order to comply with the Paris Agreement and the principles of the circular economy. The objective of this research was to develop different types of cement clinker blends using industrial waste and innovative design to produce low-energy cement. Several types of waste have been studied as alternative raw materials. Their main characteristics have been analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD), Attenuated total reflectance Fourier trans-form infrared spectroscopy (ATR-FTIR), thermal analysis (TG-DTG-DSC) and scanning electron microscopy and energy dispersive X-ray spectroscopy analysis (SEM-EDS). The results obtained from the experimental work carried out in this research focused on the study of crude blends for low-energy cement created from industrial waste. The effect of the addition of different industrial waste types, as a substitution for raw materials, in the production of low-energy cement with high dicalcium silicate content has been investigated. Thus, the dosage design has been performed using modified Bogue equations and quality indexes (LSF, AM, and SM). The calculations of both the modified Bogue equations and quality indexes necessitate knowledge of the weight percentages of CaO, SiO2, Al2O3, and Fe2O3, determined via XRF. In this theoretical design of the different blends, it has been established that a dicalcium silicate ratio of 60–65 wt % and an LSF of 78–83% as the limit are values common to all of them. The calculation basis for the crude blends has been based on calcined materials. Therefore, the chemical composition was established, following this premise. Thus, it was possible to develop cement clinker blends with compositions of 50 wt % and 100 wt % using industrial wastes. This research has shown that the clinkerization process is one of the main options for the valorization of waste and its consideration for inclusion as a raw material within the circularity of the cement industry’s production process. Thus, waste is used as a raw material for the production of a more useful substance, taking into account the fundamental principles of the circular economy.

Preparation of Geopolymeric Materials from Industrial Kaolins, with Variable Kaolinite Content and Alkali Silicates Precursors

“…These materials have been considered key to mitigating the carbon footprint and reducing the CO 2 output of cements and concretes. It should be noted that the cement manufacturing industry is one of the largest producers of GHG emissions [84,85]. For example, CO 2 contributes 65% to global warming, which must be taken into account in the current climate change conditions caused, among other reasons, by high CO 2 emissions [78,80].…”

Study of silicon dioxide nanoparticles on the rheological and mechanical behaviors of self-compacting geopolymer concrete

“…Worldwide, concrete is highly utilized and irreplaceable for innumerable significant materials for infrastructure developments that remain pivotal to addressing the growing population demand and economic development [1,2]. Cement is an essential resource for concrete production, but cement manufacturing produces CO 2 that greatly contributes to global warming [3][4][5]. Globally, cement requirement is estimated to rise by 2050, reaching 6 billion tons [6,7].…”