Extracting Alumina from Coal Fly Ash with Concentrated Sulfuric Acid Sintering and Ultrasound Aided Leaching

In this study, fly ash was modified by concentrated sulfuric acid, and it was used in the treatment of phosphorus-containing wastewater, then we have investigated the impact of the different modification conditions on the adsorption, the results show that: in the condition of 5g of fly ash by adding 0.15 mL of concentrated sulfuric acid and 3 mL water, 1.5 h of drying time, the temperature of 100°C, the effect of removaling Phosphorus is the best,and the adsorption efficiency can reach 94.6%. The adsorption rate was fast, and the adsorption can react in condition of wide pH value.

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Dewaterability of Excess Activated Sludge with Fly Ash Conditioning

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.2651 ◽

2013 ◽

Vol 726-731 ◽

pp. 2651-2654

Author(s):

Chang Nian Wu ◽

Wei Hua Li ◽

Qi Ling ◽

Li Wang ◽

Fa Kang Pan ◽

...

Keyword(s):

Sulfuric Acid ◽

Fly Ash ◽

Activated Sludge ◽

Extracellular Polymeric Substance ◽

Specific Resistance ◽

Coal Fly Ash ◽

Polymeric Substance ◽

Conditioning Process ◽

Sludge Dewaterability ◽

Sludge Conditioning

The coal fly ash (CFA)/coal fly ash modified by sulfuric acid (MCFA)-conditioned sludge dewaterability was investigated in this study. Specific resistance of filtration (SRF) was used to assess the sludge dewaterability. Extracellular polymeric substance (EPS) was determined in attempt to explain sludge conditioning process. The results showed that SRF of the sludge significantly decreased with coal fly ash addition, and the MCFA showed much stronger conditioning capacity than the raw coal fly ash. Under a MCFA dosage of 36g.L-1, the SRF of the sludge decreased from 1.18×1012 to 6.47×1010 m.kg1, and EPS concentration of the sludge decreased from 32.64 to 17.55mg.L-1. The sludge conditioning mechanisms with MCFA mainly included improving adsorption bridging and providing the water transmitting passages by skeleton builder.

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Preparation of α-Alumina from Coal Fly Ash by Sintering with Sulfuric Acid

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.113-116.2039 ◽

2010 ◽

Vol 113-116 ◽

pp. 2039-2044 ◽

Cited By ~ 4

Author(s):

Wen Ning Mu ◽

Yu Chun Zhai

Keyword(s):

Sulfuric Acid ◽

Fly Ash ◽

Coal Fly Ash ◽

Acid Leaching ◽

National Standards ◽

Sintering Process ◽

Optimal Parameters ◽

Mass Ratio ◽

Sulfuric Acid Leaching ◽

Sintering Time

A technology was studied to prepare -alumina from fly ash, and the integrated process flow including sintering with sulfuric acid, leaching, recrystallization, calcination was established in this paper. The influences including the particle size of fly ash, sintering temperature, sintering time and the mass ratio of sulfuric acid to fly ash on the extraction ratio of alumina were investigated and discussed during sintering process, and the optimal parameters were determined. The product of -alumina was examined by chemical analysis, XRD and SEM, and the results show that α-alumina reach the national standards.

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