A review on the utilization of fly ash

Alkali-activated materials

The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).

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Hallmarks of mechanochemistry: From nanoparticles to technology

Geopolymer concrete: A review of some recent developments

A review of the multi-component utilisation of coal fly ash

The invention relates to a novel purified isozyme of an autoclavable superoxide dismutase extracted from the plant Potentilla atrosanguinea Lodd. Var. areyrophylla, said isozyme having the following characteristics, O 2 − scavenging activity remains same before and after autoclaving; scavenges O 2 − from sub-zero temperature of −20° C. to high temperature of +80° C.; O 2 − scavenging activity at 25° C. for 30 days without adding any stabilizing agent such as polyols or sugars; O 2 − scavenging activity in the presence of saline (0.9% sodium chloride) to 61.8% of the control (without 0.9% sodium chloride), stable at 4° C. for at least 8 months; contamination free and infection free from any living micro- and/or macro-organism after autoclaving; possesses temperature optima at 0° C.; possesses a molecular weight of 33 kD under non-denaturating conditions; possesses a molecular weight of 36 kD under denaturating conditions; has clear peaks in UV range at 268 and 275 nm; has an enzyme turnover number of 19.53×10 4 % per nmol per min at 0° C.; and requires Cu/Zn as a co-factor, method for the preparation of the purified isozyme of autoclavable superoxide dismutase and formulations containing the said autoclavable superoxide dismutase.

Isozyme of autoclavable superoxide dismutase (SOD), a process for the identification and extraction of the SOD and use of the said SOD in cosmetic, food, and pharmaceutical compositions

In this work, municipal solid waste incinerator fly ash (MSWI-FA) was used as precursor to alter the reactivity of low reactive volcanic ash (VA) for alkali-activated cement synthesised. The effects of various proportions of MSWI-FA (0, 5, 10, 15 and 20%) on the final properties of the inorganic polymer are reported. The increase in MSWI-FA content increases the heat of reaction in MSWI-FA as the result of the reaction between the amorphous alumina-silica and the Ca-rich precursor. Isothermal conduction calorimetry, FTIR, XRD SEM/EDS, and physico-mechanical analyses were used to follow up the different formulations. New crystalline phases, namely Margarite (CaAl2 (Al2Si2)O10(OH)2, PDF#04-013-3004), Mordernite-(Ca) ((Ca, Na2, K2)(Al2 Si10 O24)·7H2O, PDF#00-011-0155) and Thernadite (Na2SO4, PDF#01-074-2036) confirm the good reactivity. The SEM/EDS exhibited the coexistence of C–S(-N-A)–H and N-A-S-H gels in binary system alkali-activated. The compressive strength and bulk density ranged from 9.38 to 21.07 MPa and from 1.56 to 1.77 g/cm3, respectively. These results indicated the possibility to use VA and MSWI-FA to synthesize room temperature alkali-activated matrices applicable in the manufacture of structural and functional materials. MSWI-FA appears energy-efficient and sustainable solution for the improvement of the volcanic ash based alkaline activated materials.

Improved Reactivity of Volcanic Ash using Municipal Solid Incinerator Fly Ash for Alkali-Activated Cement Synthesis

The mechanical properties and durability parameters such as wet-dry cycles, water sorptivity, efflorescence and acid resistance of geopolymer concrete synthesized from fly ash of three different or...

Durability and Mechanical Behavior of Fly Ash-GGBFS Geopolymer Concrete Utilizing Bottom Ash as Fine Aggregate

The invention relates to a novel purified isozyme of an autoclavable superoxide dismutase extracted from the plant Potentilla astrisanguinea Lodd Var orgyrophylla, said isozyme having the following characteristics, O 2 − scavenging activity remains same before and after autoclaving; scavenges O 2 − from sub-zero temperature of −20° C to high temperature of +80° C; O 2 − scavenging activity at 25° C for 30 days without adding any stabilizing agent such as polyols or sugars; O 2 − scavenging activity in the presence of saline (09% sodium chloride) to 618% of the control (without 09% sodium chloride), stable at 4° C for at least 8 months; contamination free and infection free from any living micro- and/ or macro-organism after autoclaving; possesses temperature optima at 0° C; possesses a molecular weight of 33 kD under non-denaturating conditions; possesses a molecular weight of 36 kD under denaturating conditions; has clear peaks in UV range at 268 and 275 nm; has an enzyme turnover number of 1953×10 4 % per nmol per min at 0° C; and requires Cu/Zn as a co-factor, method for the preparation of the purified isozyme of autoclavable superoxide dismutase and formulations containing the said autoclavable superoxide dismutase

Novel isozyme of autoclavable superoxide dismutase (SOD), a process for the identification and extraction of the SOD and use of the said SOD in cosmetic, food, and pharmaceutical compositions

The focus of this paper is on isothermal conduction calorimetric study of the geopolymerisation of mechanically activated fly ash Mechanical activation was carried out in an eccentric vibratory mill due to its high efficiency The samples used for calorimetry were characterised in terms of particle size distribution (by laser diffraction), morphology and chemical heterogeneity (by SEM–EDS) and structure (XRD and FTIR) The calorimetric response, rate of heat evolved (
 $$\dot{q}$$
 ) with geopolymerisation time (t), was collected for 24 h The 7 × 7 calorimetric maps were prepared using the data at seven reaction temperatures (TGP = 27, 32, 37, 42, 47, 53, 60 °C) for seven samples obtained after different duration of milling (tMA = 0, 5, 15, 30, 60, 90, 120 min) Comprehensive profiling of fly ash reactivity was done in terms of the maps for rate of heat evolved (
 $$\dot{q}$$
 vs time), total heat evolved (Q vs time), fraction reacted (α vs time) and iso-conversion time (tα) Each of the mechanically activated samples behaved uniquely A model-free approach based on ‘iso-conversional methods’ was deployed to analyse the kinetics of geopolymerisation The analysis revealed that activation energy changes with fraction reacted and displays three regimes of dependence The merit of the model-free analysis over traditionally used ‘model-based analysis’ is emphasised Further, in the context of geopolymerisation, empirical parameters based on fraction reacted are used to delineate efficacy of mechanical activation vis-a-vis reaction temperature

Sanjay Kumar

Papers

Isozyme of autoclavable superoxide dismutase (SOD), a process for the identification and extraction of the SOD and use of the said SOD in cosmetic, food, and pharmaceutical compositions

Improved Reactivity of Volcanic Ash using Municipal Solid Incinerator Fly Ash for Alkali-Activated Cement Synthesis

Durability and Mechanical Behavior of Fly Ash-GGBFS Geopolymer Concrete Utilizing Bottom Ash as Fine Aggregate

Novel isozyme of autoclavable superoxide dismutase (SOD), a process for the identification and extraction of the SOD and use of the said SOD in cosmetic, food, and pharmaceutical compositions

Mapping of calorimetric response for the geopolymerisation of mechanically activated fly ash