Pilbara Minerals’ Pilgangoora project reduces misclassification

Pilbara Minerals’ Pilgangoora, located 120 kilometres south of Port Hedland, Western Australia, is one of the world’s largest hard-rock lithium-tantalum deposits.

The site contains four ore grades — high, medium, low and sub grade — with little visual difference between them. Measured blast movement is up to 15 metres, and because of the size of the ore blocks there is possibility of complete misclassification. As a result, this will negatively affect the mill blending strategy.

By implementing the blast monitoring solution, the geology team was able to account for movement of the different ore grades — reducing misclassification and ore loss.

In a recent blast, the team calculated that they had prevented 20 per cent misclassification, avoided 11 per cent dilution and increased ore yield by 7 per cent. The calculated recovered value was $335,000. By accurately measuring and adjusting post-blast dig lines for each grade, the geology team are able to supply the processing plant with a uniform feed level.

Blast Movement Technologies’ chief executive officer Jacques Janse commented, “By accounting for blast movement and controlling misclassification, Pilbara Minerals’ grade control team maximise the recovered resource from every blast.

“Our blast movement process requires blast monitors be installed throughout the shot and then detected post-blast, which the site does without impacting production.

“Pilbara Minerals is also BMT’s 100th customer, and one of many mining operations that are now improving profitability by accurately accounting for post-blast ore movement.”

More than 105 mines in 35 countries use BMT’s Blast Movement Monitoring System, including:

  • Evolution Mining’s Cowal gold mine, which calculated a 7 per cent improvement in mill head grade from monitoring their high grade correctly
  • Teck’s Red Dog zinc mine, located in Alaska, which reported additional savings of US$6.5 million per annum
  • Canadian Malartic, Canada’s largest gold mine, have estimated they saved C$7 Million in Q1 2018
  • Asanko Gold’s Nkran mine in Ghana, which reported an improvement in reconciliation from 88 per cent to 102 per cent

BMT’s research over 13 years shows the variability of blast movement makes it impossible to predict or model with sufficient accuracy for grade control. From measuring tens of thousands of blasts, we found that:

  • Actual blast movement varies from 0.5 to 30m
  • Horizontal movement is commonly ± 50 per cent from the mean
  • Movement varies within a bench, i.e. surface movement is much less than mid-bench movement
  • Movement varies across blast zones and edges

Blast Movement Technologies helps resource companies improve profitability. Its unique BMM System accurately measures 3-dimensional blast movement to increase ore yield and minimise dilution in every blast.

The company was recently recognised for its export growth with the Australian Export Awards Hall of Fame, which is for companies who have won the national award three times, and for innovation by the 2018 Prospect Awards Innovative Mining Solution award.

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