Perth: In its 2014 third quarter ‘production report’, Rio Tinto has declared a 15% decrease in diamond production of 3549000 carats for Q3-2014 as against 4158000 carats for the same period in 2013.
All the three mines, Argyle (2455000 carats), Diavik (1004000 carats) and Murowa (90000 carats) are now in production and contributed towards Rio Tinto’s diamond total output for Q3, 2014.

At Argyle, which is Rio Tinto’s main mine with its 100% interest, the carats recovered for Q3 2014 is 20% less than the 3085000 carats for the Q3 of 2013. At Diavik (Rio’s interest is 60%), however, production for Q3 2014 was more or less same as 1003000 carats for Q3 of the previous year. For Q3 2014, the 90000 carats recovered at Murowa (Rio’s 78 % interest) was higher than the 70000 carats for the same period in 2013, an increase of 29%.

Rio Tinto’s diamond production for the first 9 months of 2014 registered a decrease of 4% at 11031000 carats as against 11529000 carats for the same period of 2013.

At Argyle, the 7375000 carats recovered during the first nine months was 10% lower than the 8205000 carats in 2013, reflecting the move from open pit to underground mining and the processing of lower grade tailings in the first quarter of 2014 as underground production ramped up.

The second crusher was successfully commissioned during the third quarter which saw higher throughput offsetting lower grades to keep carat production in line with the previous quarter.
Diavik had strong operational performance in the first nine months of the year with 10% increase in 3413000 carats produced, compared to the corresponding period of 2013 when it recovered 3106000 carats.

This was due to improvements in mining rates, with all three pipes in full production, as well as processing plant improvements implemented over the past six months. Production in the third quarter was down compared to the previous quarter as a result of lower grades and throughput after the majority of stockpiled ore was processed in the first half.
The 243000 carats recovered at Murowa in the first nine months were 12 per cent higher than the 217000 carats in 2013; and 29 per cent higher in Q3 2013 due to improved throughput and grades.