The way we mine must fundamentally change
March 25, 2019
David Upton, Australia’s Mining Monthly
RADICAL new ways to mine are needed if the industry is to meet the challenge of multiple pressures threatening the industry’s viability, Australia’s Future of Mining 2019 conference has heard.
Ewan Sellers, Research Director for CSIRO and Research Leader at Mining3, told the event in Sydney the industry was being squeezed from all directions.
He said in the future, everything would be more difficult to mine, and not just because deposits were becoming smaller, deeper and lower grade.
“Three of the world’s big challenges are energy, water and fuel/diesel.” Sellers said.
“As the world population continues to grow rapidly, demand increases and prices go up. In previous times, it might not have mattered as much that miners were less efficient, but now it becomes very, very costly to both the company and also to the environment.”
Access to mineral resources is also becoming much more difficult because of competing demand for cropping land and the need to protect the environment.
“We are going to need more steel, more copper, more lithium and other battery metals,” Sellers said.
“But if we keep on going with the same technology, we are not going to be able to access many of the deposits we need to meet global demand.
“We need to make fundamental changes, starting with challenging our assumptions about whether we really need to extract all of the material that we do now.”
Sellers outlined a group of new mining methods that fell under the banner of In Place Mining: In Line Recovery, In Mine Recovery and In Situ Recovery.
In Place Mining relies on greater selectivity in the material mined and reduces materials handling, with mineral processing occurring close to, or directly at, the mine face. Scoping models already show potential to reduce energy consumption by 50% and slash capex by two thirds.
The new approaches to mining are being developed by Mining3, a collaborative research organization that includes CSIRO, a number of leading universities and industry partners such as Caterpillar, Komatsu, Barrick, Newcrest, Vale and OZ Minerals.
In Line Recovery combines precision mining and material processing at the mine face, including one or more steps such as beneficiation, pre-concentration and leaching.
In Mine Recovery is a hybrid of In Line and In Situ, with rock breakage or pre-conditioning of the ore to improve recoveries from leaching material while it is still underground. It represents a new way of open stoping and can be thought of as an underground dump leach factory.
In Situ Recovery extracts metals entirely via solution, with the orebody accessed only by a series of injector and production wells. While this concept is not new, it utilises a new generation of “green” lixiviants to replace sulphuric acid leaching.
These include glycine – a low-cost amino acid found in protein-rich foods – along with food preservative sodium thiosulphate and methanesulphonic acid, which is low in toxicity and biodegradable.
Sellers said Mining3 was working on a wide range of projects and taking a staged approach in developing those mining methods.
“There are things that can be applied in the short term, and each of those is a step towards these bigger innovations,” he said.
“It’s essential we work towards these goals now so they will be ready when we need them.
“We feel that certainly in the next three to six years, some of these approaches can be used, especially in marginal ore deposits that are associated with existing deposits.
This gives Mining3 the opportunity to test and practice these extraction methods before thy are deployed on deposits in the next six to ten years.
Sellers said the new approaches were challenging for many in the industry, who had grown up with ever-increasing scale and capex as the default option for making lower grades viable and boosting the economics of development.
These new approaches offered the potential for better financial results.
“If you are getting the same amount of revenue, but with much less capital, your return on capital is much higher,” Sellers said.
“The potential huge reductions in capex also means miners have a better chance of securing finance to develop that would otherwise be stranded.”
Sellers said he had worked for many years in value chain optimisation and this made clear to him the importance of the research being undertaken by Mining3.
“Often we were trying to put in small point solutions, even lots of point solutions simultaneously, but sometimes you have to change the whole system before you can make real change,” he said.
“That’s where we have to aim.”
See the original article here.