This disseminated gold mine is one of the top producing open-pit mines in Russia.

• Mineralisation is disseminated in sedimentary schists and shales
• Blasts are fired in a 10 metre bench
• The site contains high grade (3.5 g/t) and low grade ores

Challenges

Substantial movement of ore was not monitored or accounted for

• Dilution, with tonnes of waste being treated as ore
• 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 being sent to the waste pile

Results

Value of US$430,000 was added by reducing dilution and misclassification and recovering more ore

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

• Measured horizontal movement ranges from 2.5 m to 14 m (8 to 46 ft) and vertical movement of up to 4.5 m (15 ft)

As a result of accurately accounting for blast movement, this mine:

• Reduced dilution by 7%: 17,000* tonnes of waste were diverted from the mill, saving US$340,000^**
• Prevented misclassification of 50,000 tonnes (20%) of ore
• Recovered 1% (72 oz.) of gold, valued at US$90,000^***

* Numbers are rounded
** Estimate based on mine milling costs of US$20 per tonne
*** Calculated at a gold price of US$1,250/oz.