THE DIAMOND PAGE — Redaurum’s diamond production in Zimbabwe

Toronto-listed junior Redaurum Red Lake Mines, has been setting new production records half a world away.

Earlier this month, the company’s 50% owned River Ranch diamond mine in southern Zimbabwe produced a record 620 carats in a single day. The existence of diamonds in Zimbabwe has been known for a long time, but River Ranch is the first kimberlite-hosted deposit to reach commercial production. De Beers discovered the pipe in 1975, but because of political turmoil in Zimbabwe, development was deferred. De Beers subsequently concentrated its efforts on the southern side of the Limpopo river, where they found the now producing Venetia pipe.

In June, 1991, Cornerstone Investments and its 50% joint-venture partner Auridiam Consolidated NL of Australia acquired the rights to the property through open tender. During July, 1993, Redaurum completed the acquisition of Cornerstone, as well as that company’s sole asset, a 50% interest in the private operating company Auridiam Zimbabwe, which owns and operates the River Ranch mine.

Since there were no records of the work done by De Beers in the 1970s, evaluation of the deposit began anew in 1992.

The River Ranch kimberlite is a multiphase pipe that has a surface area of 5.2 hectares. The pipe is highly weathered at surface with oxidation extending down to 40 metres. Eight phases have been identified to date, all of which have economic grade.

The mine contains a proven reserve of 17.5 million tonnes of kimberlite to a depth of 150 metres. This reserve, which is sufficient to sustain open-pit mining for 15 years, is expected to yield at least 5 million carats. The partners are also exploring the 13,435-hectare Beitbridge Exclusive Prospecting Order (EPO) that surrounds the River Ranch mine, and feel that there is good potential to find additional economic pipes.

Initial pilot plant production commenced in March, 1993. Late last year, a 455,000 tonne-per-year processing plant was commissioned. The new plant, which incorporates a Heavy Media Separation (HMS) module and two X-Ray Sortex diamond recovery units, became fully operational in February. The plant is expected to yield in excess of 120,000 carats in 1994.

Plans are underway to expand the HMS plant, which will increase the mine’s output to a level of 300,000 carats by early 1995.

The company recently completed the seventh sale of River Ranch diamonds in Antwerp, Belgium, bringing the total weight of diamonds sold to 76,000 carats. These sales have been sufficient to cover the mine’s day-to-day operating costs and have contributed to various capital expenditure requirements.

Diamond exploration is currently under way on four other EPOs, and an additional nine new EPOs are expected to be approved later this year, increasing the total area to be explored by Redaurum and Auridiam to 3.8 million hectares.