Xstrata Zinc announced in early May 2012 it is increasing the planned production rate while also moving forward the startup date for its Lady Loretta underground mine project, located 140 km north-northwest of its Mount Isa operations in Queensland, Australia. At the same time, the company said it is further extending the life of its Handlebar Hill open-cut operation 20 km north of Mount Isa. The two projects will generate a net increase of about 25,000 mt/y, or 5%, in Xstrata Zinc’s annual zinc production.
Construction of the Lady Loretta project began in July 2011 to develop a greenfield, underground zinc-lead-silver mine, originally expected to begin production by the end of 2013 at a rate of 1 million mt/y. However, work on the decline, surface infrastructure and services is progressing well ahead of schedule, and Xstrata has approved expenditure of a further A$57 million to accelerate development of the mine, bringing forward the start of ore production by one year to late 2012. At the same time, the planned ore production rate has been increased to 1.2 million mt/y.
Work began immediately to secure key equipment and redesign the development infrastructure, mining plan, and associated road upgrades to accommodate the increased annual ore volume.
The accelerated development of Lady Loretta has been supported by an increase in total resources from 12.6 million mt in June 2010 to 13.3 million mt in December 2011, with contained zinc metal increasing by 12% to 1.4 million mt and contained lead metal increasing by 10% to 448,000 mt over a 12-year mine life.
The A$30-million Handlebar Hill Open Cut South project supports the third stage of expansion of this operation and extends the life of the mine by a year to 2014. Developing a narrow cutback to the south of the pit and targeting deeper ore from beneath the first two stages of development adds approximately 1 million mt of ore at 8.7% zinc, 2.7% lead, and 44 g/mt silver to the existing Handlebar Hill open-pit reserves.
Xstrata Zinc Australia COO Brian Hearne said, “We are accelerating the delivery of ore from Lady Loretta to Mount Isa by developing the upper ore bodies independently to the deeper underground resources. At the same time, we are investing in a further expansion of the Handlebar Hill operation following improvements in mining methods and metallurgical performance since the mine was designed in 2007. The improvements have allowed us to look at mining previously marginal ore.”