Improving mining functionality using an algorithm based on soap bubbles

The outcome

Miners will now be able to optimise the value of ore they are able to extract from open-cut mines using software developed by University of Melbourne researchers through their start-up company, Thinking Mine Design.

The software designs pits in nested clusters that provide connectivity and minimum bench width needed for equipment access.

“It is the first commercially available algorithm that accounts for the complex geometrical constraints of pushback design,” says Professor Hyam Rubinstein.

The changes to the way open-cut mines are designed could support values of between 5 and 15 per cent greater than previous pit construction allowed, depending on the complexity of the design.

“Leading mining companies have tested the software extensively on real data sets,” says Professor Rubinstein.

In benchmarking tests against a leading industry software provider, BubblePit delivered better value and more mineable pushbacks.

An extension of the software, BubbleSched, is a direct block scheduler – dividing up pits into a mining production schedule for the ore blocks – that includes the mineability constraints of BubblePit.

In benchmarking, direct block schedules obtained with BubbleSched were close to optimal. Moreover, the set of blocks selected for each mining period by BubbleSched, satisfy the operational constraints of minimum mining width and connectivity. Currently available commercial solvers are unable to incorporate these constraints into the optimisation of schedule value.

The need

Large-scale mining of primary resources presents a range of complex challenges. Companies have been investing heavily in finding ways to make mining more cost-effective and efficient.

Open-pit mining is the most common method used to excavate ore deposits that are relatively close to the surface of the earth.

“For decades, the industry has been trying to find a way of incorporating geometrical constraints of the shapes of the pits into the design process, in order to maximise value and satisfy operational needs,” Professor Rubinstein says.

Traditionally, open-pit mines have been built through a series of nested pits, known as pushbacks, leading to the easily recognisable terraced pits found in mines throughout the world.

Since the upfront investment in establishing mines is so significant, it’s also important to maximise the efficiency of scheduling and haulage.

Developing the solution

Software developed by mathematician Professor Hyam Rubinstein and mining engineer Dr Juan L. Yarmuch can be used to address the problems that have faced the industry for many years.

The BubblePit software uses the geometric properties of masses of soap bubbles to find the optimal design shape for the nested pits.

Key ideas for this project were developed during Dr Yarmuch’s University of Melbourne PhD, which was co-supervised by Professor Rubinstein.

After receiving a grant through AMIRA Global, the BubblePit software was completed in July 2021. The software development was supported by Australian’s Newcrest Mining and Newmont Mining, the world’s largest gold mining company. Both Newcrest and Newmont have trialled the software in their mining operations. Leading global mining company Rio Tinto also extensively tested an early version of the software.