Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Commercial-scale test of new technology to recover coal from sludge successful

17.09.2010
A new technology for removing water from ultrafine coal slurry has been successfully tested at the commercial scale at an operating coal cleaning plant. The technology offers the possibility of reducing the coal slurry impoundment problem from the source. A peer-reviewed paper on this new technology was presented Sept. 15 at the 13th Australian Coal Preparation Society Conference, Cairns, Queensland.

Cleaning coal after it has been mined is done with water. The bulk of the coal mined is relatively coarse in size and, therefore, can be readily washed of impurities and subsequently dewatered.

However, a portion of mined coal is smaller than approximately 30-40 microns – something like the size of talcum powder – and is difficult to dewater after cleaning, said Roe-Hoan Yoon, the Nicholas T. Camicia Professor of Mining and Mineral Engineering in Virginia Tech's College of Engineering. As a result, finer coal is often discarded to slurry impoundments. There are hundreds of sludge impoundments in the U.S., mostly in Appalachia, creating environmental and safety concerns, said Yoon.

Yoon presented the paper in Australia with co-author Wally Schultz, executive vice president of Decanter Machine Inc. of Johnson City, Tenn., the largest supplier of screen-bowl centrifuges internationally.

Yoon, Gerald Luttrell, Massey Professor of Mining and Mineral Engineering, and their colleagues at the Center for Advanced Separation Technologies (CAST) at Virginia Tech have developed a hyperbaric centrifuge that was patented by Virginia Tech Intellectual Properties Inc. and sublicensed to Decanter Machine. "The new technology compliments what Decanter already has," said Yoon.

Encouraged by the results of a pilot-scale test conducted in 2009, Jim Walter Resources Inc. of Brookwood, Ala. (Walter Energy) tested a full-scale commercial unit successfully. "Everything has performed as promised by Decanter," said Joel Franklin, preparation engineer for Jim Walter Resources.

In the pilot-scale test, coal slurries consisting of ultrafine coal were dewatered to less than 20 percent moisture. "The product coal feels like dry powder when you touch it because the water left with the coal is spread so thinly across its large surface area," Luttrell said.

According to a National Research Council report, the U.S. coal industry discards annually 70 to 90 million tons of fine refuse to slurry impoundments. "The dewatering technologies developed by CAST will help coal companies recover all of the mined coal. The technology can also be used to recover the coal in existing impoundments, which can help clean-up the environment and create jobs in the coal producing regions like Southwest Virginia," said Congressman Rick Boucher (D-VA 9th District), who has supported funding for CAST and other energy projects.

"We are very optimistic," said Decanter Machine Inc. President Ken Robinette.

The centrifuge technology is the most recent of the advanced technologies developed by CAST. Microcel™ flotation column was the first major separation technology developed. It uses microbubbles to separate fine coal from mineral matter that becomes ash when burned at power plants and from other impurities, and is used widely in Australia.

As part of a project funded by National Energy Technology Laboratory (NETL), CAST has developed two other advanced dewatering processes. One is the novel dewatering aids that are currently marketed by Nalco Company. The other is a technology that may be more useful for recovering and dewatering the ultrafine coal from existing impoundments, according to Yoon. Virginia Tech has applied for a patent for this new technology.

In June 2010, Yoon testified before the subcommittee of the West Virginia Legislature's Joint Standing Committee that was charged with addressing the issues concerning coal slurry impoundments. Yoon suggested that the CAST research funded by NETL can offer technological solutions.

The paper, Taking Advantage of the CentribaricTM Technology: Split Dewatering of Fine Coal , was authored by Serhat Keles, post doctoral associate in mining and minerals engineering, Luttrell, and Yoon, all of Virginia Tech and CAST; Schultz; and M. K. Eraydin of Nalco Company, Blacksburg, Va.

The U.S. Department of Energy has supported CAST research since 2002. Learn more about CAST at http://www.cast.mining.vt.edu/

Susan Trulove | EurekAlert!
Further information:
http://www.vt.edu

More articles from Process Engineering:

nachricht Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT

nachricht A laser for divers
03.05.2017 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Nagoya physicists resolve long-standing mystery of structure-less transition

21.08.2017 | Materials Sciences

Chronic stress induces fatal organ dysfunctions via a new neural circuit

21.08.2017 | Health and Medicine

Scientists from the MSU studied new liquid-crystalline photochrom

21.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>