ENDAKO

The Site:
Mine Location: Endako is located about 190 km west of Prince George, near the center of BC. It is 8.5 km southwest of the village of Endako which is 16.5 km west of the community of Fraser Lake. The mine can be reached by Highway 16, which runs between Prince George and Prince Rupert.

Mine Type: Endako is an open pit mine that extracts molybdenite, a molybdenum sulphide mineral commonly referred to as "moly", which is roasted on-site to produce molybdic oxide.

Type of Deposit: Endako ore is part of a very large, 220 million year old (Late Jurassic) granitic rock body. The molybdenite is concentrated in quartz veins in the granitic rock. The ore averages about .063% molybdenum.

The Operation:
Endako celebrated its 43^rd year of operation in 2008. The deposit was first discovered and staked in 1927, but it was not until 1964 that mine construction began. Endako has operated every year since start-up in 1965, except for between 1982 and 1986, when it closed due to low molybdenum prices. The mine currently produces about 4000 tonnes of molybdenum sulphide (MoS₂per year.

Endako is Canada's largest molybdenum producer, and one of only two mine in Canada that produces molybdenum as its primary product. It is owned and operated by Thompson Creek Metals Company. A 4500m exploratory drilling program was carried out in 2005. This led to the discovery and excavation of the new West Denak pit, which has become the mines new primary production site.

Up until 2004 Endako also operated a refinery on site that produced a 100% pure molybdenum sulphide concentrate (MolyLube) which is added to oil to produce special high temperature lubricants.

Mining Process:
Endako's ore deposit is currently mined in the West Denak pit.

The mining process here begins with blasthole drilling using three electric rotary drills. They drill a series of 32 cm diameter holes, 16 meters deep that are filled with ANFO explosives which are blasted to create 13.4m high benches in the pit. Blasting is done two or three times a week.

Ore and waste are loaded onto haul trucks by four electric shovels that move up to 60 tonnes per bucket load. The shovels load one of the ten 172 or 190 tonne haul trucks that move the ore to the primary crusher located in the pit. These trucks also move waste rock to the waste rock dump.

Ore is moved from the crusher up an 800 metre conveyor to the mill. There, grinding is done in 5 circuits, each consisting of one ball mill and one rod mill. From there, the slurry is directed to a flotation circuit that includes 1) rougher cells, 2) scavenger cells and 3) cleaner cells - in sequence - and recovers molybdenum sulphide concentrate. Tailings that sink to the bottom of the flotaion cells are piped to one of two man-made tailings pond located about 800 metres from the mill.

All of the molybedenum concentrate recovered from flotation is pumped as a slurry to a disc filter to remove water. Then it is fed into a drier by screw conveyor and finally it is moved by screw conveyor and bucket elevator to the on-site roaster where the molybdenum sulphide concentrate is converted to molybdic oxide (MoO₃). This material, which is light coloured and sparkly compared to the dark concentrate, is loaded into 10-250kg metal drums for shipping.

Ongoing Reclamation:
Endako is located on a high plateau in a picturesque region which supports abundant wildlife. At closure, land disturbed by mining will be reclaimed by the mine operators and returned to a sustainable ecosystem.The end goal of Endako's mine site reclamation plan is to return the land as close as possible to its natural state as wildlife habitat and forest. To date (mid-2008), 37% of the mine site has been reclaimed, including waste rock dumps and the lower sections of the tailings ponds. Of this ~ 8% is at the end land use objective state. The reclamation process begins with reseeding with grasses to stabilize barren surfaces in the short term and allow native species to invade in the long term. Between 20,000 to 40,000 trees and shrubs are planted each year. One of the biggest challenges is developing soil, a slow process made more difficult by the short growing season.

Currently, two tailings ponds hold the mill waste water from Endako. As the ore essentially contains only the ore mineral molybdenite, there are only trace amounts of other metallic minerals in the tailings. All tailings pond water is recycled back to the mill where it is used over and over again in the milling process; none is released to natural drainage.

Although this is a sulphide mineral mine, the ore rock is slightly basic,containing calcium-rich feldspars that naturally break down into compounds that tend to raise the pH and neutralize any acidic water generated. So, neither the tailings nor the waste rock dumps generate acid rock drainage (ARD) at Endako Mine.

At one point, waste rock from the active pits was dumped into the original open pit on site, which is near both operating pits. Today, waste rock is hauled from the pit to waste rock 'dumps'. A number of these piles which are no longer active have been reclaimed, first by resloping the surfaces to 26 degrees and then revegetating them with grasses, shrubs and trees.

The on-site roaster that produces molybdic oxide also produces sulphur dioxide (SO₂) gas as by-product, which is directed to an adjacent scrubbing plant. There the SO₂ is combined with water to produce sulphurous acid which is mixed with mine tailings. The tailings, which are naturally alkaline, combine with the acid to produce CaSO₄ (the mineral anhydrite) and neutral water, and all is piped out to and impounded in the tailings ponds. Trace amounts of SO₂ not captured by the scrubber are (with permission) released to the atmosphere.

Markets:
About 85% of molybdic oxide produced in 2008 was shipped directly to Asian Markets where is it mostly used in the production of specilaty steels that are strong, light weight, and corrosion-resistant. The remainder was sold in North America.

The People:
Employment: Endako employs about 260 people directly at the mine operation. Of them, about 110 work in the mine, 110 work in the mill, and the remainder work in engineering and administration. Mill and mine employees work 12 hours per shift, and work 4 days on, 4 days off. Geologists and engineers, as well as administration, work 40 hours a week, Monday to Friday.

Community:Most of the Endako employees live in the Village of Fraser Lake, a community of 1300 people. Fraser Lake has one primary school for grades K-3, and one elementary-high school covering grades 4-12. The mine is a major employer of people living in the community, second only to West Fraser Timber Company Sawmill.

This beautiful region also offers great outdoor recreation, attracting hunters, fishermen, birdwatchers, boaters, hikers and campers alike.

More information on Endako Mine can be found at the Endako Mine Web site.

Information and uses of: molybdenum.

April 2009 update