In its quarterly report ending March 31, Canada's Capstone Mining Corporation reported that for the three months ending March 31, the Pinto Valley open pit copper mine west of Miami produced 11,300 tons of copper, with additional by-products of zinc, molybdenum, lead, silver and gold.

Darren Pylot, President and Chief Executive Officer of Capstone, said the first quarter was challenging at Pinto Valley because “the heavy rain early in the year reduced the throughput capacity of the crusher and ultimately caused us to advance our decision to proceed with the primary crusher mainframe replacement. The rains also had an impact on grade (of copper) as we had to adjust our mine plan given the water in the pit.”

Operational highlights at the Pinto Valley Mine for the first 90 days of this year were listed as follows by Pylot:

“Copper production at Pinto Valley was impacted by a seven-day planned shutdown in January to complete repairs in the fine ore bins and the tailing thickener distribution system. Production was also impacted by considerable rain in the first quarter, with Pinto Valley receiving five inches of rain over a two-day period in late January, followed by additional rainfall in the following weeks.

“The heavy rains reduced mining productivity and slowed the primary crusher intake, delaying the return to full operations from the planned shutdown. Mine plan sequencing was changed to address high moisture in the bottom of the pit with more ore coming from the lower grade foothills area.

“Following the shutdown, saturated fine ore placed additional stress on the primary crusher mainframe. As a result, the lower frame replacement, originally deferred from the second quarter of last year, was done over 11 days in late February and early March.

“Temporary primary crushing units allowed for production at reduced rates. Full production resumed on March 9 and since then throughput has averaged 58,900 tons per day as of April 9.”