Effect of sintering temperature on the alumina extraction from kaolin

Synthesized Zeolite Based on Egyptian Boiler Ash Residue and Kaolin for the Effective Removal of Heavy Metal Ions from Industrial Wastewater

“…Utilization of solid industrial wastes by reusing them in the manufacturing of useful materials used for environmental purposes has been the subject of several recent studies and is one of the most crucial issues for maintaining sustainable development [ 21 ]. Kaolin has been widely used in many industrial applications due to its desirable physical and chemical properties, especially particle size, morphology, color, softness, non-abrasiveness, and chemical durability [ 22 ]. Moreover, its excellent physico-chemical surface properties (e.g., relatively low exchange and adsorption capacities, etc.…”

Enhanced alumina extraction from kaolin by thermochemical activation using charcoal

“…In the case of sintering at 1360°C without added charcoal, the precursor components reacted and transformed completely into the leachable calcium aluminate phase (C 12 A 7 ). The additional heat generated under these conditions facilitated the crystallization of the calcium aluminate phase (ElDeeb et al , 2019, 2020b, 2020c, 2021). The addition of charcoal up to 1.5% increased total heat during the transformation due to the combustion of charcoal in this closed system (as is indicated by the significant thermal changes on the DSC curves; Fig.…”

“…In the case of sintering at 1360°C without added charcoal, the precursor components reacted and transformed completely into the leachable calcium aluminate phase (C 12 A 7 ). The additional heat generated under these conditions facilitated the crystallization of the calcium aluminate phase (ElDeeb et al, 2019(ElDeeb et al, , 2020b(ElDeeb et al, , 2020c(ElDeeb et al, , 2021. The addition of charcoal up to 1.5% increased total heat during the transformation due to the combustion of charcoal in this closed system (as is indicated by the significant thermal changes on the DSC curves; Fig.…”

Cost-Effective and Eco-Friendly Extraction of Alumina Based on Kaolin Ore Using Thermo-Chemically Activated Lime-Sinter Process

“…The sintering method has been applied in the industrial scale and can be further classified into the lime-sinter process, lime-soda sinter process, and soda-sinter process according to the sintering mediums [19][20][21]. Aluminosilicate ores can be processed using the lime-sinter process which consists of the following successive steps: 1) Mixing the ground aluminosilicate and calcium carbonate ores in suitable stoichiometric at a suitable temperature result in the sinter mixture consisting of dicalcium silicate (2CaO•SiO2) and calcium aluminate compounds (12CaO•7Al2O3, CaO•Al2O3); (2) Alkaline leaching the produced sinter with dilute Na2CO3 solution to dissolve alumina in the form of sodium aluminate (2NaAlO2) and all silica was nearly left undissolved in addition to lime and any other materials present in the sinter; (3) Carbonization of the sodium aluminate solution with CO2 to precipitate alumina as alumina trihydrate (gibbsite) and producing the sodium carbonate solution, which can be further recycled in the leaching process or for the production of sodium carbonate powder and (4) Calcining the precipitated gibbsite at 1350°C to produce αAl2O3 phase [22][23][24][25][26].…”