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Teck’s Highland Valley Copper mine generates $100,000 additional value in one blast

Teck HVC copper mine reduces dilution

Commodity Geology Powder Factor Location
Copper Disseminated porphyry 1.2 kg/m3 Canada

Teck’s Highland Valley Copper Operations, an open-pit mine located in British Columbia, Canada, produces copper and molybdenum.

  • Drills and blasts 15m benches, which are mined in a single pass
  • Gradational porphyry copper-molybdenum deposit

Challenges

Maximising recovered value
  • Given the gradational nature of the ore body, movement was not considered to be a contributing factor to dilution or ore loss
  • However, visual identifiers on the muck pile indicated blast movement but the amount of displacement was difficult to quantify
  • Mine operations sought to further optimize the kriged model to include less inherent dilution

Solution

BMM System accurately measured blast movement and translated post-blast dig lines
  • Blast movement monitors (BMMs) were installed in monitoring holes throughout the shot
  • Installation and detection as per site standard operating procedures
  • BMM Explorer software calculated new dig lines, and areas of ore loss, misclassification and dilution that would have occurred without monitoring

Results

Accounting for blast movement reduces waste in the mill and maximizes ore yield—adding C$100,000 in one blast

Accurate tracking of blast movement helps improve operational efficiency at Highland Valley Copper.

An example blast demonstrates the extent of movement and recovered value. Movement occurs within all blasts, and horizontal movement variation ±50% from the mean is common.

  • In this blast, measured horizontal movement ranged from 2 – 11m1 (6 – 36 ft)
  • Vertical movement was up to 6.4m (21 ft)

By accurately accounting for blast movement, Highland Valley Copper:

  • Avoided 35% dilution—22,7001 tonnes of very low grade waste were diverted from the mill
  • Maximized ore yield—15,4001 tonnes of higher grade ore were recovered, avoiding 24% ore loss
The ore control team increased revenue by C$100,0002, which is calculated from the additional ore recovered minus the copper that would have been recovered from dilution if the ore blocks were mined in situ.


1. Numbers are generated from BMM Explorer and rounded.
2. Supplied by Highland Valley Copper and calculated at a copper price of US$5,500/t.
Image Credit: infotel.ca: contributed by Teck Highland Valley Copper

This blast map shows pre- and post-blast ore polygons, and areas of ore loss (pink) and dilution (brown).  In this blast, if ore bodies had been mined in their in situ positions, 22,716 t of waste would have been sent to the mill and 15,469 t of high grade ore sent to the waste pile.


Definitions

Ore loss occurs when material containing grade (ore) is incorrectly sent to a waste dump.

  • When a cost is given for ore loss, it is the sale value of the metal (copper) recovered from this ore (i.e. ore tonnes x grade x recovery rate x metal price)

Dilution occurs when waste is unintentionally mined with material containing ore and sent to the mill.

  • When a cost is given for dilution, it is the cost of processing the waste material through the mill