Meteor could hold solution to a mining issue
PERTH (miningweekly.com) – Scientists have discovered a tougher form of diamonds preserved in meteorites from an ancient dwarf planet, which could revolutionalise industrial diamond manufacturing.
A research team with scientists from Monash University, RMIT University, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Synchrotron and Plymouth University, has confirmed the existence of lonsdaleite - a nano-sized diamond that could be useful for cutting through ultra-solid materials on mining sites.
Lead study author Professor Andy Tomkins, an ARC Future Fellow at Monash University’s School of Earth, Atmosphere and Environment, discovered the unusually formed lonsdaleite crystallites when looking at ureilite meteorites in his lab.
Tomkins said it was a case of curiosity-driven science innovation that may lead to great technological advances.
“This is exactly the sort of curiosity-piquing observation that sends scientists diving down rabbit holes for months on end,” he said.
The current method for producing industrial diamonds involves chemical vapour deposition, in which diamonds are formed onto a substrate from a gas mix at low pressures.
“We propose that lonsdaleite in the meteorites formed from a supercritical fluid at high temperature and moderate pressures, almost perfectly preserving the textures of the pre-existing graphite. Later, lonsdaleite was partially replaced by diamond as the environment cooled and the pressure decreased.”
“Nature has thus provided us with a process to try and replicate in industry. We think that lonsdaleite could be used to make tiny, ultra-hard machine parts if we can develop an industrial process that promotes replacement of pre-shaped graphite parts by lonsdaleite.”
In this work, the researchers used cutting-edge electron microscopy and synchrotron techniques to create maps of lonsdaleite, diamond and graphite found in the meteorites.
Typically containing larger abundances of diamond than any known rock, ureilite meteorites are arguably the only major suite of samples available from the mantle of a dwarf planet. The parent asteroid was catastrophically disrupted by a giant impact while the mantle was still very hot, creating the ideal conditions for lonsdaleite, then diamond growth, as the pressure and temperature decreased in a fluid and gas-rich environment.
“These findings help address a long-standing mystery regarding the formation of the carbon phases in ureilites that has been the subject of much speculation,” Tomkins said.
“And, they offer a novel model for diamond formation in ureilites that settles contradictions in the existing concepts.”
RMIT Professor Dougal McCulloch, said the hexagonal structure of lonsdaleite’s atoms made it much harder than regular diamonds, which had a cubic structure.
“This study proves categorically that lonsdaleite exists in nature,” said McCulloch - director of the RMIT Microscopy and Microanalysis Facility. We have also discovered the largest lonsdaleite crystals known to date that are up to a micron in size - much, much thinner than a human hair.”
Comments
Press Office
Announcements
What's On
Subscribe to improve your user experience...
Option 1 (equivalent of R125 a month):
Receive a weekly copy of Creamer Media's Engineering News & Mining Weekly magazine
(print copy for those in South Africa and e-magazine for those outside of South Africa)
Receive daily email newsletters
Access to full search results
Access archive of magazine back copies
Access to Projects in Progress
Access to ONE Research Report of your choice in PDF format
Option 2 (equivalent of R375 a month):
All benefits from Option 1
PLUS
Access to Creamer Media's Research Channel Africa for ALL Research Reports, in PDF format, on various industrial and mining sectors
including Electricity; Water; Energy Transition; Hydrogen; Roads, Rail and Ports; Coal; Gold; Platinum; Battery Metals; etc.
Already a subscriber?
Forgotten your password?
Receive weekly copy of Creamer Media's Engineering News & Mining Weekly magazine (print copy for those in South Africa and e-magazine for those outside of South Africa)
➕
Recieve daily email newsletters
➕
Access to full search results
➕
Access archive of magazine back copies
➕
Access to Projects in Progress
➕
Access to ONE Research Report of your choice in PDF format
RESEARCH CHANNEL AFRICA
R4500 (equivalent of R375 a month)
SUBSCRIBEAll benefits from Option 1
➕
Access to Creamer Media's Research Channel Africa for ALL Research Reports on various industrial and mining sectors, in PDF format, including on:
Electricity
➕
Water
➕
Energy Transition
➕
Hydrogen
➕
Roads, Rail and Ports
➕
Coal
➕
Gold
➕
Platinum
➕
Battery Metals
➕
etc.
Receive all benefits from Option 1 or Option 2 delivered to numerous people at your company
➕
Multiple User names and Passwords for simultaneous log-ins
➕
Intranet integration access to all in your organisation