Lead-zinc-silver mineralisation occurs in a galena and sphalerite rich massive sulphide lens located in carbonaceous pyritic shales and siltstones. The deposit consists of a tight syncline dislocated by a number of major faults. The deeper and high grade portion of the deposit reaches 500m below the surface.

Drilling and blasting practices are conducted at underground operations to fragment the rock surrounding the ore. Ore from underground is mucked, crushed and hauled to the surface.

Blasthole stoping is used at Lady Loretta.

Ore mined is roughly crushed on site, then trucked to the Mount Isa mills for processing. When it reaches the processing plant it is blended with ore mined at the Handlebar Hill open cut, the Black Star open cut and the George Fisher underground mine.

First, the ore is ground into a fine dust via a series of ball mills. This dust is then mixed with water and reagents in our zinc-lead concentrator’s flotation circuit. The reagents help us to separate the valuable mineral content from waste rock. Air is forced through the slurry creating bubbles, which float to the surface and attract and bind to the zinc or lead particles. The glossy, mineral-laden “froth” is then skimmed off the top and dried. What remains once the water content of the froth has evaporated is zinc or lead concentrate. Our zinc concentrates are sold in the domestic market and exported overseas, while our lead concentrate undergoes further processing and smelting on site to become crude lead, or lead bullion.< ........