Westminer takes another look at N.S. zinc mine

Owner Westminer Canada, which currently treats 100 tons of gold ore per day (from the Forest Hill mine) in the Gays River facility, is installing pumps in the adjacent lead/zinc mine as part of a trial dewatering program.

The company plans to spend close $1 million this year to examine the possibility of re-opening the mine. Sufficient space and flotation capacity exists in the 1,500- ton-per-day mill to allow both gold ore and base metals ore to be treated separately. Some additional grinding capacity would have to be added should the mine be re-opened.

If the mine can be successfully dewatered, Westminer will examine the feasibility of mining some 1.1 million tonnes of mineralization in Mississipian-age (Windsor Group) carbonates. Grades average about 9.4% zinc and 5% lead.

The mineralization was left behind by the previous operators, Canada Wide Mines, which was controlled by Esso Minerals Canada.

The challenges of mining the mineralization are two fold, The Northern Miner gathers. The first is the amount of water in the underground workings and the second is a bed of unconsolidated till located above the limestone/gypsum contact where most of the high grade ore is located.

Esso mined portions of the deposit in 1979-82, chiefly by room and pillar mining methods using jumbo drills, diesel Scooptrams and haulage trucks. That work stopped considerably short of the unconsolidated rock unit.

Mechanized cut-and-fill methods using cable bolts to support the back as mining progresses up to the limestone/gypsum contact will likely be considered.

Grouting or dewatering of the mine area are two possible ways to deal with the in-flow of ground water into the mine. Groundwater travels in a series of aggregate-filled channel ways within the carbonate formation. But the location of the channel ways is completely unpredictable.

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