CeO2-dolomite as fire retardant additives on the conventional intumescent coating in steel substrate for improved performance

Multiple combinations of CeO2-Dolomite as fillers and Intumescent Flame Retardant (IFR) ingredients were used to optimize the intumescent coatings designed for I-beam steel substrates. The influenced of fillers and various combinations of flame-retardants on the fire protective performance of the coatings were evaluated using vertical Bunsen burner fire test and various characterization techniques. Formula C and Formula F having 1:1 and 2:2 CeO2-Dolomite ratio, obtained the lowest substrate temperature around 150oC and 150.4oC, respectively after 90 minutes fire exposure. Also, the morphological structures of intumescent char observed by SEM-EDX, demonstrated that Formula C and Formula F stimulated the formation of homogeneous and more compacted surface structure. X-ray photoelectron spectroscopy (XPS) provide the binding energies of C and O constituents, it was observed that [-(C2H4)n-] was the most important free radical as it could promote the formation of aromatic carbon chain in the char surface. Finally, the findings of this study revealed that the selection of appropriate fillers and combinations of flame-retardant ingredients significantly influenced the morphological structure of the char layer, of which, Formula C and Formula F produced a char with higher thermal stability, resulting to a more fire resistive IFR coating during fire exposure

CeO

Multiple combinations of CeO2-Dolomite as fillers and Intumescent Flame Retardant (IFR) ingredients were used to optimize the intumescent coatings designed for I-beam steel substrates. The influenced of fillers and various combinations of flame-retardants on the fire protective performance of the coatings were evaluated using vertical Bunsen burner fire test and various characterization techniques. Formula C and Formula F having 1:1 and 2:2 CeO2-Dolomite ratio, obtained the lowest substrate temperature around 150oC and 150.4oC, respectively after 90 minutes fire exposure. Also, the morphological structures of intumescent char observed by SEM-EDX, demonstrated that Formula C and Formula F stimulated the formation of homogeneous and more compacted surface structure. X-ray photoelectron spectroscopy (XPS) provide the binding energies of C and O constituents, it was observed that [-(C2H4)n-] was the most important free radical as it could promote the formation of aromatic carbon chain in the char surface. Finally, the findings of this study revealed that the selection of appropriate fillers and combinations of flame-retardant ingredients significantly influenced the morphological structure of the char layer, of which, Formula C and Formula F produced a char with higher thermal stability, resulting to a more fire resistive IFR coating during fire exposure

Hydrochloric Acid Leaching of Philippine Coal Fly Ash: Investigation and Optimisation of Leaching Parameters by Response Surface Methodology (RSM)

Coal Fly Ash (CFA) is a hazardous waste from coal-fired power plants, but has increasingly become a popular supplementary cementitious material for cement in the construction industry. As a secondary resource of REE, its main advantage lies in its fine particle size that eliminates the need for costly and energy-intensive comminution. In this study, the potential of CFA from the Philippines as a secondary REE resource was investigated by direct leaching of REEs with hydrochloric acid (HCl). The CFA sample came from a coal-fired power plant with a circulating fluidized bed combustion (CFBC) technology. For the leaching tests, the effects of HCl concentration, leaching time and leaching temperature on REE extractions were elucidate optimized via Response Surface Methodology (RSM). The RSM results showed that the optimum leaching occurred at 3M HCl, 65 °C and 270 min with extractions of Nd, Er, Eu, Tb and Dy at 70.8%, 76.34%, 88.02%, 90.01% and 73.38%, respectively. According to these results, the CFA from the Philippines is a promising secondary resource of REE and the extraction method employed was effective in achieving a relatively high REE dissolution. Moreover, the empirical model that was established accurately predicted the dissolution of REE with an accuracy of 98.20%, 96.66%, 97.09%, 98.17% and 97.78% for Nd, Er, Eu, Tb and Dy, respectively