Article from resourceful: Issue 12
As ore quality declines around the world, it's more important than ever before for mining companies to be able to optimise their processes for greater efficiency and productivity.
Understanding the properties of complex ores and how they behave during mineral or metal processing at a fundamental level is essential for accurately assessing the viability and impact of making any process modification.
CSIRO team leader, Dr Nathan Webster, says the ability to "see" into a dynamic process and understand how it works takes niche expertise and can't be accurately achieved in traditional post-mortem style analyses.
"Our ability to truly understand an industrial process is hampered when a product sample is taken from the operation into the laboratory for analysis," says Dr Webster.
"Whether it's a hydro- or pyro-metallurgical process, an electrochemical process or a materials synthesis reaction – when a sample is removed from operating conditions its characteristics will naturally change due to different environmental conditions.
"For example, mineral phases (mineral species) that are stable at high temperature, and under highly reducing conditions, may react during cooling or when exposed to air."
Simulating industrial processes for greater accuracy
CSIRO has the unique ability to simulate the industrial process using x-ray technology, overcoming the limitations of traditional lab-based analyses, ensuring accurate results. They are able to recreate process conditions such as extremes of temperature, pressure and gas atmosphere.
Dr Webster's team worked recently to drive process efficiencies in the electrowinning process.
"Replacing the industry standard lead-based alloy used in copper electrowinning with an alternative material could lower energy and material consumption, as well as reduce downtime and maintenance costs," Dr Webster says.
"It's important to understand what the impacts different lead alloys would have on the process. We did this by simulating the process with our x-ray diffraction techniques.
"We carried out both electrochemical and diffraction measurements simultaneously on each of the alloys, assessing not only their electrochemical performance but their characteristics that could affect the end product's mechanical integrity.
In another example, a top-tier mining company sought to get a better understanding of the effect of particular gangue minerals on iron ore sintering operations.
"We simulated the iron ore sintering process and tracked the mineral phase evolution throughout the process, revealing the mineralogical changes as a function of temperature and time for each ore type," Dr Webster says.
"We were able to improve the company's understanding of the influence of the various gangue minerals on the final product, and the desirable ore properties for processing."
Rapid characterisation with big datasets
CSIRO has a range of advanced diffraction-based characterisation technologies in their toolkit, including some of the most advanced equipment in Australia. Dr Webster likened the team's approach to a "high-throughput" one.
"We acquire a large amount of information in only a few hours. This would have taken days or weeks using traditional laboratory analysis methods.
"By rapidly handling large amounts of data, our customers get more insight in a quicker timeframe, which helps them to save costs."