Canadian Mining Journal


Advanced Project News

Kidd's Mine D Gets Go-AheadThe Falconbridge Ltd. board of directors approved the development of a new mine, Mine D (Deep), at the Kidd Creek operations in Timmins, Ont. The feasibility study, complete...

Kidd’s Mine D Gets Go-Ahead

The Falconbridge Ltd. board of directors approved the development of a new mine, Mine D (Deep), at the Kidd Creek operations in Timmins, Ont. The feasibility study, completed in June 2000, concluded that Mine D will contribute 2 million tonnes of ore annually at full production. The mine will extend from 2,100 m to 3,100 m below surface at the Kidd Creek mine; production will begin in 2004.

The mine will be developed in two stages. Stage One will take the mine down to about 2,700 m depth. This portion of the mine is estimated to contain 15.7 million tonnes of ore grading 2.82% Cu, 5.74% zinc and 58 grams/tonne Ag.

Stage Two development will begin in 2009, and will take it down to 3,100 m depth, making Kidd the deepest base metal mine in the world. The second stage contains an estimated 10.5 million tonnes of ore grading 2.20% Cu, 5.27% Zn and 97 grams/tonne Ag.

The new mine will require a total investment of $640 million, including inflation. Most of this will be spent during Stage One, including a number of start-up components such as the sinking of a new internal shaft, the installation of a new ventilation and refrigeration system, and the acquisition of new underground mobile equipment.

Initial Metallurgy and Marketing for Finlayson Project Complete

The initial stage of process metallurgy and concentrate marketing for the Finlayson project in the Yukon has been completed, and the results were better than expected, according to Brad Marchant, vice-president of mining and development for Expatriate Resources Inc. The Finlayson project combines development of the Kudz Ze Kayah deposit (recently acquired by Expatriate from Cominco Ltd.) and the Wolverine deposit owned by the Wolverine joint venture (60% Expatriate, 40% Atna Resources Ltd.).

The metallurgical studies included locked cycle flotation and concentrate roasting. The testing confirmed that the Wolverine ore can be co-mingled with Kudz Ze Kayah ore, resulting in an improvement over previous flotation results for Wolverine alone. Based on a mill feed ratio of 3,000 tonnes per day from Kudz Ze Kayah and 1,250 tonnes per day from Wolverine, the combined operation would produce, on an average annual basis, 40,000 tonnes of copper concentrate, 32,600 tonnes of lead concentrate and 201,700 tonnes of zinc concentrate. The recoveries of zinc, lead and copper to final concentrate were 91%, 64% and 81%, respectively. Overall silver recovery to concentrates was 85%, and gold recovery was 73%.

Results from the roasting test work, completed at RPC in Fredericton, NB, on the combined Wolverine-Kudz Ze Kayah zinc concentrate, confirm that selenium can be effectively removed and that significant economic advantages can be realized in marketing a clean, higher grade zinc oxide product.

As well there were initial discussions with interested smelters in Japan, Korea, Canada and Europe. The response of the smelters to the zinc sulphide and oxide products has been very positive. The high precious metal content of the copper concentrate is attractive for many copper smelters.

The prefeasibility study is in progress and on schedule for completion late this year.

Excellent Economics for Jericho Diamond Project

The results of the Jericho diamond project feasibility study are in, and they look very good for 100%-owner Tahera Corp. As a result, the company plans to proceed to project financing. SRK Consulting completed the feasibility study. Dowding Reynard & Associates provided detailed diamond plant engineering for the study, and Nuna Logistics provided the open-pit mining cost estimates.

SRK used an average modeled diamond valuation of US$75 per carat, 17% lower than the results from a study completed by WWW International Diamond Consultants in late 1999.

The project is located in the Territory of Nunavut, about 420 km northeast of Yellowknife, Northwest Territories, and 170 km north of Ekati, Canada’s first diamond mine. The study centred on the land-based Jericho kimberlite pipe.

The study indicates that about 3.0 million carats will be produced over an eight-year mine life. The current plan consists of open-pit mining 1.9 million tonnes of kimberlite reserves for the first four years, followed by underground mining of 614,000 tonnes of kimberlite. About 80% of the mining reserve is derived from the high grade Central Lobe, with lesser amounts from the Northern and Southern lobes.

The overall stripping ratio for the pit is 8.4. The underground mine will be accessed from the open pit via a decline. Underground mining will use a combination of sub-level caving and open benching mining methods. The proposed 50-tonne/ hour processing plant will lie about 1 km from the Jericho kimberlite. The containment area for processed fines will be close to the plant; coarse rejects will be stockpiled and used for reclamation.

It is anticipated that project permitting will be complete by the second quarter of 2001. Prestripping is to take place in the first half of 2002, and the plant is to be built and commissioned during the second half of the same year. Open pit mining is expected to commence in the second quarter of 2003, and underground development and mining in 2006.

About 100 people will be employed during construction. The diamond plant will require 40 employees year-round. The open pit contractor will employ about 104 people for nine months per year, while the underground mining contractor will engage about 24 people for three years.