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Organic Phase Change Materials
Published in Asit Baran Samui, Smart Polymers, 2022
Swati Sundararajan, Asit Baran Samui
A phosphamide-containing silsesquioxane matrix, with an average pore diameter of 4.1 nm, is used as a supporting matrix for the preparation of fire-retardant PCM. With 82 wt% PEG, the melting enthalpy can be as high as 125 J g−1 at a melting temperature of 56°C.106 Bischofite, a by-product of the non-metallic mining industry, is obtained during potassium chloride production with a major component of MgCl2.6H2O.107 MgCl2.6H2O itself is a well-recognized inorganic PCM. Its cycling performance can be most satisfactorily improved by adding 5% PEG. However, high supercooling of 37°C remains a disadvantage.
Solution mining
Published in M.L. Jeremic, Rock Mechanics in Salt Mining, 2020
Buyze and Lorenzen described for magnesium salt solution in the Netherlands that faster salt influx is, in contrast, anticipated in the carnallite and bischofite zone. As a result, a pressure difference between the cavern fluid and the far field rock is being transmitted at a high rate through the salt layers of high ductility. Consequently, if those layers intersect adjacent caverns, the carnallite and bischofite stress inside the pillars will be affected from all sides and will finally approximate to cavern fluid pressure.
Petrophysical and rock-mechanical characterization of the excavation-disturbed zone in tachyhydrite-bearing carnallitic salt rocks
Published in Manfred Wallner, Karl-Heinz Lux, Wolfgang Minkley, H. Reginald Hardy, The Mechanical Behavior of Salt – Understanding of THMC Processes in Salt, 2017
T. Popp, K. Salzer, M. Wiedemann, T. Wilsnack, H.-D. Voigt
The formation of the tachyhydrite in general and its specific but frequent occurrence in the Teutschenthal area in association with kieserite have not been well understood until now. On the basis of isothermal equilibrium studies d‘Ans (1961) has debated several possibilities how tachyhydrite might have been formed. Accordingly, the physico-chemical prerequisites are quite lucid. The general question of its occurrence in the Teutschenthal area revolves around its association with kieserite even though the CaCl2-enriched solutions, which are required for tachyhydrite should exclude the presence of MgSO4 (thus, kieserite). According to Rösler & Koch (1968) the formation of tachyhydrite with decreasing halite is conceivable, as “primary segregation” in the carnallite and bischofite region of oceanic salt deposits. The known German deposits might have been formed in a metamorphous manner by the decomposition of carnallite or from high-temperature CaCl2-enriched metamorphous solutions. Thus, it is possible to explain the common occurrence of tachyhydrite together with carnallite, halite, kieserite and partially sylvinite without any formation of anhydrite seams.
Toward the Implementation of Circular Economy Strategies: An Overview of the Current Situation in Mineral Processing
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Luis A. Cisternas, Javier I. Ordóñez, Ricardo I. Jeldres, Rodrigo Serna-Guerrero
The control of dust in mining areas frequently uses water; another way to reduce water consumption is to apply a more efficient way for dust depressing. Gunson et al. (2012) found that road dust suppression was significant water-consuming processes, accounting for about 9% of total water use, and concluded that an optimal road dust suppression method was the use of a dust binder on the road network. A natural product available worldwide used for dust suppression that can reduce water consumption is Bischofite (MgCl2 · 6H2O), normally obtained from salt flats or salty lakes in either solid or diluted form (Jones and Surdahl 2014). In this context, Gonzalez et al. (2019) indicated that water consumption in one year for the irrigation of haul roads in an open-pit mine is on average 153 times higher than the water required for roads treated with Bischofite.