In this paper, alkali activation of the waste remaining after shale oil retorting in solid-heat-carrier plants was investigated to improve the cementitious properties of this waste. Oil shales are low calorific fuels leaving upon processing large amounts of solid waste with limited secondary use, mostly because of low self-cementitious properties. The low Î♁3C value of carbonate is rather caused by the non-equilibrium fractionation effects during diffusion and hydroxylation reactions of CO2 in hyperalkaline conditions under a limited CO2 diffusion rate. The negative isotopic composition of carbonate carbon seemingly points to a contribution of CO2 derived from the degradation of residual organic material, potentially present in shale retorting ashes. The secondary carbonate phases forming in oil shale waste deposits have low Î♁3C and Î♁8O values characterized by Î♁3CV-PDB values between -12â° and -24â° and Î♁8OV-PDB between -8â° and -15â°. We studied the isotopic composition of authigenic carbonate phases in an alkaline Ca-rich oil shale ash waste deposit accumulated over nearly 50 years to reveal the carbonation mechanisms and the sources of CO2 required for carbonation. The solid residues remaining after combustion are upon open air deposition potentially capable of binding part of the released CO2 by carbonation of reactive Ca-phases. The Estonian energy industry relies on local calcareous oil shale that is used to produce the majority of the countryâs electricity, but the shale is also used for shale oil retorting. This systematic review provides a thorough understanding of gaps and existing opportunities for research and is expected to motivate researchers to be involved in this range of studies. More investigations are required to provide a better understanding of the mechanical properties and durability of OSA-based concrete for its mass usage in broad applications and widespread in the construction industry. However, this utilization negatively affects several aspects of each type of the reviewed material. This review concluded that the utilization of OSA in construction materials has considerably interesting pathways and presents a basis for future optimization in concrete, mortar, geopolymer, building blocks, glass–ceramic, aggregate, asphalt binder, and soil stabilization agent. The bibliometric mapping was implemented for the keyword’s occurrence and the tested properties of construction materials containing OSA. Overall, 528 publications were collected and then screened to 38 studies. This review aims to survey the research efforts on using OSA for construction applications and map the research views from the literature through a coherent and systematic mixed reviewing methodology (bibliometric analysis and systematic review). OSA can be used in the various applications of the construction industry and building technology to minimize environmental risks and promote sustainability. Oil shale ash (OSA) is proven as a self-cementitious material that consists of two parts a cementitious part represented by its high content of CaO, and a Pozzolanic part represented by its content of Al2O3, SiO2, and Fe2O3. The study showed that self-cementing properties of black ash are governed by the hydration of secondary calcium silicates (e.g. However, the coarse fraction (>125 µm) did not exhibit any cementation, thus the hydraulic disposal with grain size separation should be avoided. About 80% of strength was gained in 30 days. Black ash exhibited good self-cementing properties with maximum compressive strength values of >6 MPa after 90 days. Three disposal methods were simulated in laboratory experiment: hydraulic disposal with and without grain size separation, and dry dumping of moist residue. The objectives of this research were to study the composition and self-cementing properties of black ash by simulating different disposal strategies in order to find the most appropriate landfilling method. Usage of oil shale is growing worldwide, and the employment of large SHC retorts increases the amount of black ash type of waste, but little is known about its physical and chemical properties. The pyrolysis of oil shale using solid heat carrier (SHC) technology is accompanied by large amount of environmentally hazardous solid residue-black ash-which needs to be properly landfilled. Oil shale-type organic-rich sedimentary rocks can be pyrolysed to produce shale oil.
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