Formation of carbonate phases and their effect on the performance of reactive MgO cement formulations

Improving the carbonation resistance of Na2CO3-activated slag mixes via the use of reactive MgO and nucleation seeding

“…nesquehonite). The peak at ~80°C corresponded to the water loss of C-(A)-S-H [49,50], while the peak at ~120°C was due to the water loss of carbonate phases [31,51]. The shoulder at ~200°C was related to the water loss of hydrotalcite [52].…”

“…(ii) Dehydroxylation (250-450°C): Mass loss due to the decomposition of hydroxyl groups of hydrotalcite and magnesium carbonates (e.g. hydromagnesite), corresponding to an endothermic peak at ~350-370°C [31,32,52,53].…”

“…Additionally, the formation of a hydrotalcite phase with layered double hydroxides could increase CO2 absorption [27,28] and enhance the resistance to carbonation in AAS systems [29,30]. Furthermore, the reaction between hydrated reactive MgO and CO2 can form HMC phases [31,32], which can provide a binding network that fills the pore space and decreases the diffusivity of CO2, thereby improving the carbonation resistance of SCAS mixes.…”

The role of wastewater treatment plants as tools for SARS-CoV-2 early detection and removal

“…Apart from the natural transmission of SARS-CoV-2 virus from human to animals, studies have reported of experimental inoculation of the virus to animals and study the possibility of transmission from animals and the transmission route by putting in the same cage infected and non-infected animals and having other animals in another cage close to the first [ [63] , [64] , [65] , [66] ]. This has demonstrated that ferrets and cats are highly susceptible to the virus, whist dogs are less susceptible and livestock (pigs, sheep and ducks) studied were not found to be susceptible It is to be noted that those tests were done on a limited number of animals, so how representative they are of the species as a whole is not entirely known.…”

Synthesis of Brucite from Reject Brine and its Direct Carbonation for Possible Use as Construction Material

“…Reactive magnesium oxide (MgO) cement (RMC) has been shown to exhibit a significant mechanical property development under concentrated CO2 curing, attributed to the hydration of MgO to form brucite and its further reaction with CO2 to form interlocking carbonates of higher unit volume [1]. RMC is conventionally produced for calcination of magnesite (MgCO3) at a temperature between 700-1000 o C. Despite limited sequestration of CO2 as a result of carbonation, the environmental benefit of RMC as a construction material is in doubt.…”