Process Engineering for Advanced Chemically Bonded Ceramics (CBC)

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We aim to achieve room- or near-room T processed low-cost, low-CO2 emission Chemically Bonded Ceramics CBC with high-T (> 1000C) resistance and targeted ion encapsulation (e.g. heavy metals or nuclear waste) properties. (I) room- or near-room-temperature processing, and (II) use of chemical reactions, rather than sintering, to achieve ionic/covalently bonded materials, will be utilized. Properly processed CBC may lead to high-T (>1000C) resistant ceramics obtained in a low-T (<100C) processes as the chemically reacting CBC form ionic/covalent bond and undergo phase transformations at elevated T. The kinetics of these processes will be studied to determine the speed of fire resistance increase of such CBCs exposed to elevated T. Because of the above two fundamentals (I, II) of CBC processes and their mineral/waste raw materials, their CO2 footprint could be up to 10x smaller as compared to OPC. Specifically, we propose research into advanced CBCs for (A) structural and (B) functional applications broadly related to environmental protection, in two Themes 1,2: Theme 1: Basic and Applied Studies on (1A) Structural and (1B) Functional Acid-Activated Phospho-Silicate Cements (PhD#1). The long-term objective is to develop process technology for phosphoric acid bonded mineral-derived, low-cost low-alkali (Na, K) calcium alumino-silicates (such as anorthite) as (1A) viable replacement of structural OPC, and (1B) functional high-temperature (refractory) ceramics. An overlap between 1A and 1B allows to obtain in a simple, room-temperature process large volumes of high-temperature resistant cements for applications in fire-sensitive residential, transportation (e.g. tunnels), industrial (e.g. petrochemical) or military structures. Theme 2: Basic and Applied Studies on Alkali-Activated (2A) Structural and (2B) Functional Geo-Polymers GP (PhD #2). The is focus on low-cost, room-temperature processing of alkali-activated metakaolinite and waste materials such as aluminosilicate fly-ash for (2A) structural applications of amorphous, low-CO2 footprint GP targeting general OPC replacement, and (2B) functional applications of microstructurally-engineered, in-situ zeolite-crystallized GP targeting absorption and retention of Cs, Sr, As, or heavy metals Pb, Hg.