Operations affected

 NEWCREST Mining Ltd says production at its Hidden Valley in Morobe during last December quarter was badly affected due to human and technical disruptions to operation there.

According to the company’s quarterly report for last December, on December 6, an employee was fatally injured when struck by a reversing loader in the milling area. 

The mine’s inspectorate suspended the use of mobile equipment in and around the processing area, which resulted in a mill shutdown due to the inability to remove scats.

However, the company’s report stated that milling restarted on December 25.

On November 17 last year, a belt tear occurred on the overland conveyor (OLC) resulting in 7km of belt being replaced. Ore was hauled to the mill by truck from the Kaveroi pit during this period adversely impacting costs. 

Further, significant rain events occurred at end of last December and continued through the first half of last month, washing sections of 

road away and interrupting the flow of fuel and reagent supplies to site.

The company reported that Hidden Valley’s all-in-sustaining-cost (AISC) in per ounce was significantly higher than prior quarter as a result of the events detailed above. Meanwhile, Lihir’s last December’s production increased by 4 per cent over last September’s quarter but was below expectations principally due to unplanned maintenance issues. 

The company reported that higher production quarter on quarter was attributable to a higher percentage of ore feed being sourced ex-pit, a higher percentage of ore being fed directly to the autoclaves and a marginal increase in head grade – this was 

partially offset by lower recoveries and 

unplanned maintenance in the conveying circuit, grinding circuit and autoclaves 1 and 4.