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 Fraunhofer researchers develop measuring system for ZF factory in Saarbrücken
21.11.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP

nachricht New manufacturing process for SiC power devices opens market to more competition
14.09.2017 | North Carolina State University

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

Im Focus: A transistor of graphene nanoribbons

Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."

Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

Blockchain is becoming more important in the energy market

05.12.2017 | Event News

 
Latest News

Making fuel out of thick air

08.12.2017 | Life Sciences

Rules for superconductivity mirrored in 'excitonic insulator'

08.12.2017 | Information Technology

Smartphone case offers blood glucose monitoring on the go

08.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>