Beneficiation of coal pond ash by physical separation techniques

Lee, Sung‐Joo; Cho, Hee-Chan; Kwon, Jihoe

doi:10.1016/j.jenvman.2012.03.034

Cited by 11 publications

(8 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reactivity of pond ash depends on its size fraction; the fine fraction shows pozzolonic activity and can be used in cement and concrete (16), whereas the coarser fraction shows only weak pozzolanic activity. This has led to beneficiation using mineral processing techniques to separate the size fractions for possible use as a lightweight aggregate (17). Lee et al also produced geopolymer pastes with reasonable strength from South Korean pond ashes after carbon removal and drying but without size fractionation (14,15).…”

Section: Introductionmentioning

confidence: 99%

Properties of geopolymer binders prepared from milled pond ash

et al. 2017

View full text Add to dashboard Cite

Alkali-activated materials were prepared from pond ash from the Darkhan city (Mongolia) thermal power station. This ash contains about 60 wt % X-ray amorphous material in addition to quartz, mullite, hematite and magnesioferrite, and presents significant storage problems since it is accumulating in large amounts and is a hazardous waste, containing 90-100 ppm of the heavy metals As, Pb and Cr, and about 800 ppm Sr. Alkali-activated materials synthesized from the as-received pond ash achieved compressive strengths of only 3.25 MPa. Reduction of the particle size by mechanical milling for up to 30 min progressively increases the compressive strength of the resulting alkali-activated geopolymer up to 15.4 MPa. Leaching tests indicate that the combination of milling and alkali treatment does not cause the release of the hazardous heavy metals from the product, making it suitable for construction applications. RESUMEN: Propiedades de geopolímeros preparados a partir de cenizas de estanque.Se prepararon materiales activados alcalinamente a partir de cenizas de charca de la central térmica de Darkhan (Mongolia). Esta ceniza contiene alrededor de un 60% en peso de material amorfo además de mullita, hematita, cuarzo y magnesioferrite. Presenta además importantes problemas de almacenamiento ya que se acumula en grandes cantidades y es un desecho peligroso, que contiene entre 90-100 ppm de metales pesados como Pb y Cr, y alrededor de 800 ppm de Sr. Los materiales sintetizados a partir de las cenizas de estanque presentaron resistencias a compresión de tan sólo 3,25 MPa. La reducción del tamaño de partícula por fresado mecánico hasta 30 min aumentó las resistencias mecánicas hasta valores de 15.4 MPa. Las pruebas de lixiviación indican que la combinación de molienda y activación alcalina no causan la liberación de los metales pesados peligrosos del producto, por lo que resulta adecuado para aplicaciones en construcción.PALABRAS CLAVE: Cenizas de estanque; Molienda; Cementos activados alcalinamente; Resistencias a compresión; Microstructura ORCID ID: J. Temuujin

show abstract

Section: Introductionmentioning

confidence: 99%

Properties of geopolymer binders prepared from milled pond ash

et al. 2017

View full text Add to dashboard Cite

show abstract

“…This behavior of combustibles at lower density media and coarser particle sizes has also been reported in literature. 9,15 In finer particle size of −4+2 mm, the recovery of volatile matter and fixed carbon was negligible because the maximum coal particles reported in floats had been recovered at −6.25+4 mm. Figure 6 shows the percent increase of GCVs at different specific gravities and coal samples of different sizes.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of the washability characteristics of Khushab coal (Pakistani) by heavy media separation process

Sana

Kanwal

Akhtar

et al. 2017

Energy & Environment

View full text Add to dashboard Cite

The use of high-sulfur Pakistani coals can cause serious problems of slagging and fouling in thermochemical conversion reactors along with environmental issues like acid rain, etc. In this study, a pre-combustion technique, namely heavy media separation, is employed for the cleaning of low-grade Pakistani coal. Six crushed coal samples of different particle sizes were individually subjected to heavy media solutions of ZnCl2 of different specific gravities. It was found that the sample with a particle size of −6.25+4 mm at specific gravity of 1.4 produced the optimum float product as clean coal, showing 83.53% yield of clean coal with 1.24% ash and 1.0% sulfur contents. An overall reduction of 91.68% in ash and 86.11% sulfur contents was obtained. Moreover, up to 19.3% enhancement of gross calorific value was achieved. The resultant clean coal can be used in various energy recovery schemes in Pakistan such as coal-fired power plants and cement industries.

show abstract

“…In other cases, the surface of the shaking table is modified by grooves and strips. An additional factor improving separation is the use of asymmetric shaking of the table [8,9].…”

Section: Introductionmentioning

confidence: 99%

Arguvan linyitinden kül ve kükürt uzaklaştırılmasında farklı gravite yöntemlerinin etkisinin belirlenmesi

Korkmaz

2021

ALKÜ Fen Bilimleri Dergisi

View full text Add to dashboard Cite

This study, it is aimed to find out the beneficiation of Malatya-Arguvan lignite by gravity methods. First of all, the washability of lignite has been investigated with sink-float experiments. It has been determined that lignite washability from washing curves is generally difficult but may be possible with controlled washing at a density of 1.68 g /cm 3 . Then, to remove ash and sulfur from lignite by shaking table, spiral and Falcon concentrator tests were conducted. Clean coals are obtained from all other methods except Falcon were found to decrease in ash and sulfur content and increase in calorific value. Clean coals with the lowest ash and sulfur content were obtained with a spiral concentrator. Reichert spiral results showed that the ash content decreased from the lignite of 37.77% to 26.50% and the sulfur content from 3.85% to 2.08%. The calorific value increased from 2576 kcal/kg to 4590 kcal/kg. Arguvan lignite has very limited usage due to its lower calorific value, high ash and sulfur content. Although enrichment has been carried out, it has been concluded that lignite needs to be further improved by using different methods.

show abstract

Beneficiation of coal pond ash by physical separation techniques

Cited by 11 publications

References 7 publications

Properties of geopolymer binders prepared from milled pond ash

Properties of geopolymer binders prepared from milled pond ash

Evaluation of the washability characteristics of Khushab coal (Pakistani) by heavy media separation process

Arguvan linyitinden kül ve kükürt uzaklaştırılmasında farklı gravite yöntemlerinin etkisinin belirlenmesi

Contact Info

Product

Resources

About