Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microwaves could take the grind out of the rock business

16.05.2003


The feasibility of using microwaves to extract minerals from rocks has been demonstrated by UK researchers.



This revolutionary technique could cut mining and mineral processing industry costs, and make it viable to process previously uneconomic mineral reserves. It could also help the environment by saving energy as 3 – 5% of the world’s entire electrical energy output is used for the size reduction of rocks and minerals.

The technique has been developed by engineers at the University of Nottingham, with funding from the Swindon based Engineering and Physical Sciences Research Council.


Conventional practice is to crush chunks of mined ore (containing copper or zinc, for example) and then grind them into smaller pieces using energy-hungry grinding mills. Typically, only 1% of the energy consumed in rock grinding actually results in size reduction, making the process very inefficient.

The new research has investigated the use of microwaves to weaken mineral ores prior to the grinding mill stage. It has focused on the principle that rocks are made up from many constituent minerals, some of which heat rapidly and expand when subjected to microwaves, while others do not heat and expand at all. This stress causes the rock to weaken and crack. It will then fall apart much more easily in the grinding mill.

The research team has looked at the best way to microwave different rock types. This has involved using computer simulations to calculate the timing and power of microwaving required, and then testing these calculations in a microwave cavity where the rocks are exposed to the microwaves. The team has found that some rocks need to be microwaved for less than a tenth of a second to produce the desired effect.

The work has attracted considerable interest from the mining industry and a major company plans to put it into practical application, if further tests prove successful.

The research has been led by Dr Sam Kingman of the University’s School of Chemical, Environmental and Mining Engineering. Dr Kingman says: “Grinding accounts for over half of the operating costs in a typical metal ore mine. The new technique could reduce these grinding costs by over 50%”.

Jane Reck | alfa
Further information:
http://www.epsrc.ac.uk

More articles from Process Engineering:

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

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

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>