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Canadian Malartic increased recovered value by CA$7 Million in Q1 2018

 

Commodity Ore Grade Geology Powder Factor Location
Gold 1.10* g/t Disseminated Porphyry 0.69 – 0.96 kg/m3 North America

Canadian Malartic, Canada’s largest operating gold mine, is located in Quebec, Canada.

  • Bulk-tonnage, low-grade Archean gold system mine
  • Mineralisation is disseminated gold-bearing pyrite hosted in porphyritic felsic
  • Ten-metre benches are mined in a single pass

Challenges

Blast movement of ore was not accurately measured or accounted for

Blast movement of ore was estimated1 and not accurately measured, which resulted in:

  • Misclassification of ore (i.e. high grade ore is stockpiled as low grade or low grade ore is sent to the mill as high grade)
  • Ore loss, with gold bearing ore sent to the waste pile
  • Dilution, with tonnes of waste being treated as ore

Solution

The BMM System accurately transposed 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

Increased recovered value by up to 7 Million2 CAD during Q1, 2018

Accurate monitoring of blast movement helped Canadian Malartic recover 217,000 tonnes of ore, valued at $7 Million, in Q1 2018.

An example blast, shown right, demonstrates how monitoring blast movement recovers more ore.

Significant movement occurs within all blasts. Variation of ±50% from the mean horizontal movement is common and occurred in this blast.

  • Measured horizontal movement3 ranged from 3.8 – 7.9 m (12 – 26 ft) and vertical movement was up to 1.5 m (5 ft)

As a result of accurately accounting for movement in this blast, Canadian Malartic:

  • Avoided 6% dilution because 11,688 tonnes of waste were diverted from the mill
  • Prevented 14,138 tonnes (8%) of ore being misclassified and sent to the wrong stockpile
  • Maximized ore yield—6,858 tonnes (4%) of ore, valued at CA$159,8854, was not sent to the waste pile

* Average grade of ore polygons;
1. Prior to implementing the BMM System in December 2012;
2. Calculated from 70 production blasts Jan – Mar, 2018;
3. Movement measured by BMT’s BMM System;
4. Calculated at a gold price of CA$1,800/oz.

“BMT has made a significant improvement to grade and recovered tonnes. I would definitely recommend BMT.”

Mr. S. Lajoie, Technicien Géologie – BMM, Canadian Malartic

In this blast, Canadian Malartic avoided the potential loss of CA$159,885 (4% of ore was not sent to waste) and prevented 6% dilution (11,688 tonnes) and 8% misclassification (14,438 tonnes).