Leaching of heavy metals by citric acid from fly ash
· The leaching behavior of heavy metals from municipal waste incineration (MWI) fly ash was investigated in this study. The leaching process includes two steps i.e. fly ash was firstly washed with water and then subjected to citric acid leaching. The main parameters of the washing process such as liquid/solid ratio washing time and number of washing were tested.
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Acid ResistanceCement
The use of slag cement increased acid resistance as well as portland cements with silica fume (up to 8 percent by mass of cementitious material) or fly ash. Carbonation by Contact with Water Natural waters usually have a pH of more than 7 and seldom less than 6. Even waters with a pH greater than 6.5 may be aggressive if they contain bicarbonates.
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Citric Acid Effect in High early Type Portland Cement
The influence of citric acid in the properties of high strength Portland cement pastes and mortars both in fresh and hardened condition was evaluated. The content of citric acid varied from 0 to 0.8 wt . Tests were carried out in cement pastes to determine the water required for normal consistency and initial and final setting times. Mortars cements were tested to define bulk density
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Leaching of heavy metals by citric acid from fly ash
extraction can be achieved with citric acid under the fol-lowing conditions pH 3.0 liquid/solid ratio 40 (ml g) citric acid concentration 0.10 mol/dm3 contact time 20 min at room temperature. Keywords Fly ash Valuable elements Leaching Citric acid Introduction Huge amounts of wastes are generated by daily life all over the world.
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Influence of citric acid on the hydration of Portland cement
Cement pastes were prepared with a w/c of 0.4 by adding 1 kg cement to 400 g distilled water. To study the retardation of citric acid (C6H8O7) on the hydration three different concentration of citric acid were added to the mixing water equivalent to 0.1 0.4 and 0.5 wt. of ⁎ Corresponding author.
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Effect of Citric Acid on the Time-Dependent Rheological
The citric acid dosages of 0.15 0.25 and 0.35 can stabilize the rheological properties of MOC paste in 1 2 and 3 h respectively. The addition of citric acid prolonged the setting stage by introducing free H that weakened the flocculated structure of MOC paste and delayed the formation of 5 MgO · MgCl 2 · 8 H 2 O. The early compressive
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Development of sucrose and citric acid as the natural
· citric acid in geopolymerization. As presented in Figure 1 sucrose has some sort of retarding effect compared to acceleration mechanism hold by citric acid. It is considerably different from the ordinary Portland cement (OPC) based system where both of those chemical reagents have similar retarding effect in the hydration of OPC binder 6-8 .
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ACID ATTACK IN CONCRETEinsaatkisehir.edu.tr
· acid attack on concrete the influence of calcium hydroxide on acid resistance is best illustrated through examining the effect of the combination of portland cement with other cement components such as fly ash since this leads to a dilution of portland cement resulting in lower ca(oh) 2 levels. the influence of fly ash content is shown in
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Acid ResistanceCement
The use of slag cement increased acid resistance as well as portland cements with silica fume (up to 8 percent by mass of cementitious material) or fly ash. Carbonation by Contact with Water Natural waters usually have a pH of more than 7 and seldom less than 6. Even waters with a pH greater than 6.5 may be aggressive if they contain bicarbonates.
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Development of sucrose and citric acid as the natural
· citric acid in geopolymerization. As presented in Figure 1 sucrose has some sort of retarding effect compared to acceleration mechanism hold by citric acid. It is considerably different from the ordinary Portland cement (OPC) based system where both of those chemical reagents have similar retarding effect in the hydration of OPC binder 6-8 .
Get PriceACID ATTACK IN CONCRETEinsaatkisehir.edu.tr
· acid attack on concrete the influence of calcium hydroxide on acid resistance is best illustrated through examining the effect of the combination of portland cement with other cement components such as fly ash since this leads to a dilution of portland cement resulting in lower ca(oh) 2 levels. the influence of fly ash content is shown in
Get PriceCitric Acid Effect in High early Type Portland Cement
The influence of citric acid in the properties of high strength Portland cement pastes and mortars both in fresh and hardened condition was evaluated. The content of citric acid varied from 0 to 0.8 wt . Tests were carried out in cement pastes to determine the water required for normal consistency and initial and final setting times. Mortars cements were tested to define bulk density
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Effect of Citric Acid on the Time-Dependent Rheological
The citric acid dosages of 0.15 0.25 and 0.35 can stabilize the rheological properties of MOC paste in 1 2 and 3 h respectively. The addition of citric acid prolonged the setting stage by introducing free H that weakened the flocculated structure of MOC paste and delayed the formation of 5 MgO · MgCl 2 · 8 H 2 O. The early compressive
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CITRIC ACID AS A SET RETARDER FOR CALCIUM ALUMINATE
· The exothermic reaction energy that was promoted in this way minimized the loss in strength of the citric acid-retarded cement. The phase composition assembled in both retarded and non-retarded cements after autoclaving at 180 C encompassed three reaction products hydroxyapatite (HOAp) hydrogrossular and boehmite which are responsible for strengthening the autoclaved cement.
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· Abstract. Citric acid added as set retarder significantly contributed to enhancing the setting temperature and to extending the thickening time of a calcium aluminate phosphate (CaP) geothermal cement slurry consisting of calcium aluminate cement (CAC) as the base reactant and sodium polyphosphate (NaP) solution as the acid reactant.
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The effects of material ratio fly ash and citric acid on the compressive strength and phase composition of magnesium oxysulfate (MOS) cement have been studied. From these results when the molar ratio of active MgO/MgSO4 increases from 3 to 5 the compressive strength of magnesium oxysulfate cement
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Citric Acid Effect in High early Type Portland Cement
The influence of citric acid in the properties of high strength Portland cement pastes and mortars both in fresh and hardened condition was evaluated. The content of citric acid varied from 0 to 0.8 wt . Tests were carried out in cement pastes to determine the water required for normal consistency and initial and final setting times. Mortars cements were tested to define bulk density
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Leaching of heavy metals by citric acid from fly ash
· The leaching behavior of heavy metals from municipal waste incineration (MWI) fly ash was investigated in this study. The leaching process includes two steps i.e. fly ash was firstly washed with water and then subjected to citric acid leaching. The main parameters of the washing process such as liquid/solid ratio washing time and number of washing were tested.
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CITRIC ACID AS A SET RETARDER FOR CALCIUM ALUMINATE
· Abstract. Citric acid added as set retarder significantly contributed to enhancing the setting temperature and to extending the thickening time of a calcium aluminate phosphate (CaP) geothermal cement slurry consisting of calcium aluminate cement (CAC) as the base reactant and sodium polyphosphate (NaP) solution as the acid reactant.
Get PriceCement Chemistry and Additivesslb
· cement faces its toughest challenge under ground—in oil and gas wells where envi- ronmental conditions are far more severe than any encountered on the earth s surface. This artic e outlines the chemistry of port- land cement the variety used to cement casings in wells and provide zona isolation and explains how additives faci itate cement
Get PricePAPER OPEN ACCESS Effect of citric acid on setting-time
· citric acid-producing microorganisms. Aspergilus niger is a microorganism that can be used in the production of citric acid. The use of citric acid as a retarder is an environmentally friendly material. Environmentally friendly alternative materials that could substitute cement both partially or totally have been developed using waste material such as fly ash 11 .
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Citric acid as a set retarder for calcium aluminate
· Citric acid added as set retarder significantly contributed to enhancing the setting temperature and to extending the thickening time of a calcium aluminate phosphate (CaP) geothermal cement
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EFFECTS OF CHEMICAL REAGENTS ON THE PROPERTIES
· alternative chemical reagents such as sodium nitrate calcium nitrate citric acid sucrose and di-potassium hydrogen phosphate with dosage of 0.5 1.5 and 2.5 were studied to overwhelm these issues in high calcium geopolymer. The effect of these admixtures on fresh geopolymer was evaluated by considering the setting time and flow
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Oilfield ChemicalsCementing Products
Oilfield ChemicalsCementing Products. LIST OF DRILLING AND MUD ADDITIVES. AEEA -Amino Ethyl Ethanolamine. Ammonium Bifluoride. Barite. Bentonite. Bromides. Calcium
Get PriceResistance of Mineral Admixture Concrete to Acid Attack
ASTM Type I Portland cement was used throughout the investigation. Silica fume and fly ash was used as the SCM. The silica fume was procured from Elkem India and the fly ash was collected from a local thermal power plant. The chemical physical and other important char-acteristics of all cementitious materials are presented in Table 1. The
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Effect of citric acid on the hydration of portland cement
Abstract Effect of lactic acid on the hydration of portland cement has been studied by employing various experimental techniques. Results indicate that lactic acid accelerates the hydration contrary to other α-hydroxy carboxylic acids which act as retarder. Electrical conductivity measurements give an indication that lactic acid forms a salt of calcium lactate during the interaction with
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Effect of citric acid on the hydration of portland cement
Abstract Effect of lactic acid on the hydration of portland cement has been studied by employing various experimental techniques. Results indicate that lactic acid accelerates the hydration contrary to other α-hydroxy carboxylic acids which act as retarder. Electrical conductivity measurements give an indication that lactic acid forms a salt of calcium lactate during the interaction with
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citric acidslb
· CitriC ACid (C 6 H 8 O 7) is a commercial chemical used to reduce pH precipitate soluble calcium and sequester iron. It is used to reduce pH and remove calcium when drilling cement to reduce the potential of crosslinking polymers (xanthan and others) from
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· Magnesium Oxychloride Cement Modified by Aluminum-leached Coal Fly Ash. Applied Mechanics and Materials 2012 . (EI) 4 Wu Chengyou Yu Hongfa Dong Jinmei et al. Effects of material ratio fly ash and citric acid on
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