Mineral Processing Efficiency: Technology and Process Control Opportunities

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From mining to manufacturing, improved efficiency and a stronger bottom line generally go hand in hand – and factors are now combining which should make process efficiency shoot up to the top of the list of priorities. 

Following the economic downturn, companies should be looking to make the most of the growing demand for commodities, while new environmental targets means resource use is of increasing importance in processing efficiency. 

New Equipment

In August 2010, European bauxite, alumina and aluminium processing company MAL enlisted the help of Wier Minerals to boost its efficiency at its plant in Ajka, Hungary, which produces 300,000 tonnes of alumina a year. 

MAL was being restricted by the different compositions of the bauxite coming from Serbia and Hungary, which restricted the efficiency, with the end result being 31 percent of the material entering the mill not being suitable for further processing, a case study on the Weir Minerals website details. 

The company saw the installation of two Cavex 500 CVX Hydrocyclones, which automatically separated and retrieved larger solids from the slurry and sent them back to the mill, as the answer. Since installation, the system has achieved "1200g/l with an 80mm spigot, with a working life of approximately 800 hours." 

Elsewhere, companies are looking for solutions which provide more efficient use of resources, with some taking old concepts and bringing them into the 21^st century. 

VBV Holdings has seen positive results from the testing of its new slurry pump, which uses pumped water to move the slurry, based on a system which was first developed in 1935.

"By pumping water, we effectively manage to pump slurry at the same efficiency as a centrifugal water pump. The Phoenix slurry pumping system pumps at between 70 percent and 80 percent efficiency, compared with a conventional slurry pump that has a far lower efficiency," Dr Murray Bredin, managing director of International Slurry Pumping Solutions, told Mining Weekly. 

The company's system allows slurry to enter two vessels using gravity, before water is pumped into the top of the vessel, forcing the slurry back out again. 

"A unique feature of our technology is the ability to discharge slurry at a constant pressure and flow rate, even as the system switches from vessel to vessel," Dr Bredin added. 

The company is currently in the process of commercialising the pump. 

Improved Analysis and Automation

On the other side of the coin, mining companies are looking to improve their analysis techniques to boost mineral processing efficiency. 

Researchers at CSIRO have previously worked on computational fluid dynamics (CFD) modelling, which monitors patterns in various items of equipment, including hydrocyclones and gravity separation devices.

Dr Phil Schwarz, from the Minerals Down Under Flagship,highlighted: "CFD allows us to identify complex flow patterns, reactions and heat transfer occurring at a range of scales within these unit operations.

"Having this understanding means we are able to optimise processes and equipment mathematically, which means there's less of a need to construct expensive pilot plants."

Using new models and technologies like these essentially offer greater accuracy and insight than was previous available, with the end result being improved efficiency. 

In the Analyzing Slurry Size On Line paper, Malvern Instruments outlines the benefits which can be seen by bringing particle size monitoring online, moving away from the traditional online manual system, which was affected by factors like operator bias. 

It claims that taking the process online can "increase throughput, support the stable production of more optimally sized particles, reduce plant down-time, lower costs and improved process efficiency." 

Automated solutions like these are playing an increasingly important role in the industry; one which is likely to be relied on more in the future as companies look to grow in the face of skills shortages.

If this article was of interest to you, check out extra articles and podcasts on our Mineral Processing Plant Design and Construction event site: www.mineralprocessingplant.com.au/Event.aspx?id=340196