Search results for "fly ash utilization"

showing 3 items of 3 documents

Selective recovery of phosphorus as AlPO4 from silicon-free CFB-derived fly ash leachate

2018

The prospect of phosphorus (P) recovery from siliceous fly ash was investigated. The phosphorus content in the pristine fly ash was 1.21%. Obtaining pure phosphorus products from fly ash is very challenging because of high concentration of other elements, silicon (Si) at 17.3% being the major contaminant. The fly ash was fractionated with sieve size of 125 μm to concentrate the phosphorus in the small-size fraction, which also facilitated the removal of 78% of silica (Si) in the solid phase. The fractionated fly ash was treated with 8 M HCl in order to remove 98% of Si by aging (5 h) of leachate until precipitation of Si-gel, and a phosphorus-rich solution is obtained. Iron (Fe) is also con…

AlPO4 precipitationpiiSilicon020209 energyphosphorus recoverychemistry.chemical_elementrauta02 engineering and technology010501 environmental sciencesRaw material01 natural sciencescomplex mixturesIndustrial and Manufacturing EngineeringironImpurity0202 electrical engineering electronic engineering information engineeringMaterials Chemistryrecovery (recapture)lentotuhkaLeachatephosphorusta116ta215fosfori0105 earth and related environmental sciencesPrecipitation (chemistry)Fe-EDTA chelationPhosphorusfungiMetals and Alloyssiliconfly ashfly ash utilizationchemistrytalteenottoReagentFly asherottaminen (tekniikka)Nuclear chemistry
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Particle size based recovery of phosphorus from combined peat and wood fly ash for forest fertilization

2016

Abstract Correlations between the concentrations of P, K, and As with particle size in fly ash from power plants were examined with a viewpoint to obtain fractions suitable for forest fertilization. Fly ash samples from several CHP plants were fractionated by using four sieves and the five fractions were analyzed by ICP-OES; it was found that both P and K are concentrated in smallest size (

Peat020209 energyGeneral Chemical EngineeringPhosphorusEnergy Engineering and Power Technologychemistry.chemical_element02 engineering and technology010501 environmental sciencesforest fertilizer01 natural sciencesphosphorus recyclefly ash utilizationFuel TechnologyHuman fertilizationchemistryFly ashEnvironmental chemistry0202 electrical engineering electronic engineering information engineeringEnvironmental scienceParticle sizeta116ta215ta2180105 earth and related environmental sciencesFuel Processing Technology
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Removal of silicon from CFB-derived fly ash leachate in the context of phosphorus recovery

2018

High concentrations of dissolved silica in the acid leachate impose two major challenges on precipitation based recovery of phosphorus (P). Firstly, co-precipitation of colloidal silica in the acidic regimes decreases the purity and value of precipitated P-products. In addition, silica scaling on internal surfaces of equipment is also a problematic issue in industrial operations. Therefore, removal of dissolved silica prior to P-recovery process minimizes the risks of Si-contamination in P-products and Si-scaling. In the present study, silica removal was achieved by accelerated silica polymerization with higher acidity and ionic strength of mineral acid, which also assisted the leaching of …

piiDissolved silicaSiliconColloidal silicachemistry.chemical_element02 engineering and technologyIndustrial and Manufacturing Engineeringphosphorus recyclesilica polymerization020401 chemical engineeringMaterials ChemistrylentotuhkaLeachate0204 chemical engineeringta116ta215fosforichemistry.chemical_classificationChemistryMetals and AlloysMineral acidrespiratory system021001 nanoscience & nanotechnologyfly ash utilizationtalteenottoChemical engineeringIonic strengthFly ashsilica removalLeaching (metallurgy)0210 nano-technologyHydrometallurgy
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