A new approach to capture and store CO(2) by mineral carbonation using recyclable ammonium salts was studied. This process integrates CO(2) capture with mineral carbonation by employing NH(3), NH(4)HSO(4), and NH(4)HCO(3) in the capture, mineral dissolution, and carbonation steps, respectively. NH(4)HSO(4) and NH(3) can then be regenerated by thermal decomposition of (NH(4))(2)SO(4). The use of...

Coal combustion by-products such as fly ash (FA), brine and CO(2) from coal fired power plants have the potential to impact negatively on the environment. FA and brine can contaminate the soil, surface and ground water through leaching of toxic elements present in their matrices while CO(2) has been identified as a green house gas that contributes significantly towards the global warming effect...

Limestone is widely used in the construction industry to produce Portland limestone cement (PLC) concrete. Systematic evaluations of hydration kinetics, compressive strength development, and carbonation resistance are crucial for the rational use of limestone. This study presents a hydration-based model for evaluating the influences of limestone on the strength and carbonation of concrete. Firs...

In this work, the potential of CO₂ mineral carbonation of brucite (Mg(OH)2) derived from the Mount Tawai peridotite (forsterite based (Mg)₂SiO4) to produce thermodynamically stable magnesium carbonate (MgCO3) was evaluated. The effect of three main factors (reaction temperature, particle size, and water vapor) were investigated in a sequence of experiments consisting of aqueous acid leaching, e...

Carbonation of magnesiumand calcium-silicate minerals to form their respective carbonates is one method to sequester carbon dioxide. Process development studies have identified reactor design as a key component affecting both the capital and operating costs of ex-situ mineral sequestration. Results from mineral carbonation studies conducted in a batch autoclave were utilized to design and const...

The cost associated with the application of large volume of cement and synthetic admixtures was one of the major drawbacks of Self Compacting Concrete (SCC), which can be reduced by the use of supplementary cementitious materials (SCM). When the demand of cement reduces, the release of carbon dioxide (CO2) from cement industries will come down, which has a positive impact on global w...

The authors present a computational system that can deal with pH fluctuations and the decomposition of cementitious materials exposed to various environmental actions. In order to evaluate the fall in pH due to carbon dioxide, material models are developed for the transport and equilibrium of carbon dioxide, ionization, ion equilibriums, and the carbonation reaction based on thermo-dynamic theo...

This study provides a semi-probabilistic approach to durability design of reinforced concrete structures, subjected carbonation-induced corrosion. The method was developed from an existing and using comprehensive data collated the literature. A statistical model for predicting accelerated carbonation coefficient, as input variables mix proportions test conditions also generated. performance pro...

EFFECTS OF CARBONATION ON THE MINERAL COMPOSITION OF CEMENT KILN DUST By Cecilia P. Anderson Department of Geological & Mining Engineering & Sciences