Enhanced Resource Recovery by Beneficiation and Direct Acid Leaching of Fly Ash

ABSTRACTAn investigation was conducted into the use of beneficiated ash fractions as feed materials for direct acid leaching to recover Al and other metals. A low-Ca (1.4% CaO) ash was selected from which four fractions (classifier fines, classifier rejects, magnetic concentrate, and non-magnetics) were produced by mineral beneficiation methods. The raw ash and the four ash fractions were leached with 6 M HCl under reflux. Mass balance data were obtained to determine extraction efficiency for Si, Al, Fe, Ca, Mg, Na, K and Ti. It was found that size separation of the ash had a marked influence in enhancing extraction efficiency from the fine fraction for all of the elements studied except Fe. Extraction of Fe from the magnetic fraction was less efficient than from the non-magnetic fraction. Examination of the solid residue after leaching showed that, although most of the acid-soluble components were removed from the glassy phases of the ash, a significant part of the ash comprised non-reactive glass of high-Si content. A relationship between extractable Al in ash and leachable alkali and alkaline earth metals was identified and discussed in terms of glass modification theory.

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Extraction properties of β-aminophosphine oxides towards lanthanides and alkaline earth metals

Open Chemistry ◽

10.2478/s11532-012-0124-0 ◽

2012 ◽

Vol 10 (6) ◽

pp. 1933-1941 ◽

Cited By ~ 4

Author(s):

Ekaterina Matveeva ◽

Elena Sharova ◽

Alexander Turanov ◽

Vasilii Karandashev ◽

Irina Odinets

Keyword(s):

Ionic Liquid ◽

Metal Ions ◽

Phosphine Oxide ◽

Separation Factor ◽

Alkaline Earth ◽

Extraction Efficiency ◽

Alkaline Earth Metals ◽

Neutral Media ◽

Extraction Properties

AbstractThe investigation of the extraction properties of a series of polyoligodentate β-aminophosphine oxides 1–8 bearing from one to six phosphine oxide groups in a molecule towards Ln(III) and alkaline earth metals ions from neutral media has revealed that, using common diluents, the extraction efficiency increases with an increase of a number of P=O functions in a ligand. The addition of ionic liquid, namely 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([bmim][NTf2]), significantly increasing the extraction efficiency and application of IL concentration of 0.05 M (in 1,2-dichloroethane) providing the maximum recovery of metal ions with Lu/La separation factor reaching up to 91. Hexapodal tris[bis(2-diphenylphosphorylethyl)aminoethyl]amine 8 demonstrates the highest extraction under all conditions applied and the separation factor for U and Eu of this compound exceeded 103.

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Polyfunctional Derivatives of Imidodiphosphoric Acid as Extractants

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19970620 ◽

1997 ◽

Vol 62 (4) ◽

pp. 620-625 ◽

Cited By ~ 5

Author(s):

Oldřich Navrátil ◽

Petr Sládek ◽

Alena Tokárová ◽

Eckhard Herrmann ◽

Moein Nouaman

Keyword(s):

Aqueous Phase ◽

Distribution Ratio ◽

Alkaline Earth ◽

Functional Group ◽

Extraction Efficiency ◽

Ester Group ◽

Alkaline Earth Metals ◽

Strontium Barium ◽

Extraction Constants ◽

Derivatives Of

The distribution of calcium, strontium, barium and scandium between aqueous and organic phases was studied using 0.1 M HNO3 or 0.01 to 0.1 M HCl as the aqueous phase and solutions of selected derivatives of organophosphoric reagents containing the conventional =P(O)NHP(O)= bifunctional group or the analogous trifunctional or tetrafunctional group in various organic solvents as the organic phase. The effect of substitution of one ester group by an OH or NH2 group was examined. While for the alkaline earth metals the distribution ratio increases if the bifunctional group is replaced by a higher-functional group, the reverse is true for scandium. The extraction efficiency is improved by the presence of OH or NH2 substituent groups. The composition of the extracted species was inferred by logarithmic analysis and the corresponding extraction constants were calculated.

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Combined organic acid leaching and torrefaction as pine wood pretreatment before fast pyrolysis

Thermal Science ◽

10.2298/tsci180726287w ◽

2019 ◽

Vol 23 (Suppl. 5) ◽

pp. 1403-1411 ◽

Cited By ~ 2

Author(s):

Roel Westerhof ◽

Stijn Oudenhoven ◽

Xun Hu ◽

Swaaij van ◽

Sascha Kersten

Keyword(s):

Alkaline Earth ◽

Produced Water ◽

Acetic Acid Solution ◽

Fast Pyrolysis ◽

Acid Leaching ◽

Wood Particle ◽

Alkaline Earth Metals ◽

Pine Wood ◽

Pre Treatment ◽

Pyrolytic Lignin

Reducing pine wood particle size is beneficial for acid leaching (shorter leaching time, smaller equipment size) and also for pyrolysis (low pyrolysis time, high oil and sugar yields). Torrefaction helps to improve the energy efficiency of grinding. However, it is not well established whether alkali and alkaline earth metals can still be removed effectively, after torrefaction, by leaching with an acetic acid solution, while keeping high oil and sugar yields. To investigate this, an experimental study was carried out combining torrefaction (290?C, 20 minutes) and subsequently acid leaching of pine wood as pretreatment step before fast pyrolysis of the feedstock at 530?C. The oil, char, gas, water, pyrolytic lignin, light oxygenates and levoglucosan yields were compared with the results obtained from fast pyrolysis of untreated pine wood and acid leached pine wood at 530?C. In addition, pyrolysis vapors were condensed step-wise into two distinguished fractions (condensation T = 80?C) to increase the levoglucosan concentration up to 45 wt.% with or without applying torrefaction as pretreatment. Intra-particle reactions during torrefaction are more profound in the presence of alkali and alkaline earth metals. Cellulose and lignin derived products (e.g. levolucosan (~0.2 kg/kg pine wood) and pyrolytic lignin (~0.11 kg/kg pine wood) were not affected by the torrefaction pre-treatment of acid leached pine wood. In general, torrefaction of acid leached pine wood followed by fast pyrolysis showed similar total organics, char, gas, light oxygenates and produced water yields compared to fast pyrolysis of acid leached pine wood. Contrary, when acid leaching is applied after torrefaction the organics (dry bio-oil) and light oxygenates yields are quite comparable to the results of untreated pine wood fast pyrolysis.

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