Hecla will spend $6.6 million to boost Republic gold output

For the past five years the high- grade mining operation has been a production cornerstone for 100% owner and operator, Hecla Mining (NYSE). Although Hecla is still viewed primarily as a silver producer, gold has been the leading contributor to corporate earnings since 1985.

One of the lower-cost mines in North America, Republic turned out 80,000 oz of gold in 1988 and about 55,000 oz in the first nine months of 1989, plus appreciable amounts of silver.

With cash production costs of only $94(US) per gold equivalent oz in 1988, it’s small wonder that Hecla is planning an accelerated program to expand reserves and extend the life of the underground mine.

This work will involve driving 6,500 ft of decline and development drift into the Golden Promise area of the mine; improving ventilation for the existing mine; and upgrading of facilities and equipment. The decline will also access new zones of mineralization discovered through underground and surface diamond drilling.

According to Ralph Noyes, Hecla’s vice-president of metal mining, Republic’s proven and probable ore reserves were 527,000 tons of 0.9 oz gold per ton at the beginning of 1989. “This accelerated development will allow us to access new vein systems, greatly increasing the mine’s life expectancy,” he stated. “Work on the decline and ramp system will begin immediately, and we’ll be hiring about 20 new employees to help with the project.”

When Hecla gained control of the Republic mine in 1981 (by way of acquiring Day Mines), it had been in almost continuous operation for over 50 years and was thought to be near exhaustion. The company planned to mine out known vein structures and at one time even announced the pending closure of the mine.

But the timely discovery of new vein systems resulted in a new lease on life for the aging mining operation which turned out its two- millionth ounce this summer. Hecla controls a 5-sq-mi land package in the area surrounding the Republic mine and surface exploration is expected to continue.

The new development program is aimed at converting known mineralized zones into proven and probable ore reserves and to provide a base for an expanded underground exploration program.

In addition to accelerating development of known ore reserves, the program is also intended to provide a low-cost method of bringing ore to surface without tramming it more than a mile underground to the Knob Hill No 2 shaft. The inclined shaft and winze required to hoist ore reach a vertical depth of 1,774 ft.

Production and development at Republic are limited by the hoisting capacity of the Knob Hill No 2 shaft which was commissioned in 1938. Currently all ore and waste must be hoisted up this shaft. The new decline will allow rubber-tired vehicles to drive directly to and from the underground workings, allowing an increase in mining and development activities.

In particular, the decline will access newly discovered mineralization in the Belligerent vein system, some 600 ft northwest of the current workings. It will also allow access to ore-grade intercepts in other mineralized areas. Some of these intercepts are thought to be on an extension of the Last Chance vein, about 600 ft northwest of the Belligerent vein system.

Meanwhile, Hecla has replaced old equipment on the 240-ton-per- day mill in order to increase capacity to 270 tons per day. A fines treatment circuit is being installed in the crushing plant to improve operational and metallurgical control in grinding and flotation.

A new counter-current decantation circuit, which separates liquids from solids, will also be installed before year-end to replace the 52-year-old, 5-tray thickener.

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