Bulk sampling nears completion at Tiomin’s heavy mineral

Beach sand could soon become a “hot item” in this sleepy little fishing village on Quebec’s North Shore.

Tiomin Resources (ME) is collecting a 100-tonne sample of heavy mineral concentrate from its Natashquan heavy mineral sands deposit for processing and test-marketing.

On a recent site visit, President Oliver Lennox-King told The Northern Miner that collection of the sample should be completed within the next couple of weeks, at an estimated cost of $100,000.

Natashquan, 200 km east of Sept-Iles, is one of the largest known mineral sands deposits in the world. On just 30% of the 288-sq.-km property, Tiomin has outlined a dredgable resource of 1.6 billion tonnes grading 8% heavy minerals. The minerals include magnetite, ilmenite and rutile, zircon and garnet.

The heavy mineral-rich sands form a large, beak-shaped, 5×10-km deposit at the mouth of the Natashquan River.

Drilling and seismic profiling indicate the deposit is at least 40 metres thick and underlain by 15-30 metres of marine clay. The unconsolidated sediments overlie Ordivician-aged limestones and Grenville-aged basement rocks.

The sands consist chiefly of quartz, feldspar, garnet, olivine, magnetite and ilmenite. They are buff-colored and contain lenticular layers of black iron-rich sand up to 0.3 metres or more in thickness, 0.3-3 metres wide and 3-15 metres long.

The source of the deposit is believed to be reworked glacial debris from metamorphosed iron-titanium-bearing lithologies to the north. Drilling was first performed in 1906, when the Quebec Mines Branch outlined a small iron reserve. Since the 1950s, several major companies, such as Hanna Mining, Cleveland Cliffs and Quebec Iron & Titanium, have explored the deposit. Previous evaluations focused on the sands as an iron ore resource, and as a result there was a lack of information on the other economic heavy minerals.

The bulk sample is being collected using a pilot concentrating plant. To generate the sample, the sand is first excavated, then mixed with water to create a slurry and screened to remove any stones. The slurry is pumped to the top of a spiral concentrator (a specially designed circular shoot; see accompanying photo) where the heavy minerals are separated from the lighter material, based on specific gravity. The heavies are collected and the lights are put back in place.

The pilot plant is producing a concentrate which contains 65-75% heavy minerals.

Once collected, the bulk sample will be sent for processing at the Centre for Mineral Research in Quebec City. Processing will involve subdividing the sample into individual concentrates of magnetite (iron), ilmenite and rutile (both titanium), zircon and garnet.

Titanium is primarily used as a pigment in paint, plastics and paper. Zircon is used in molds, furnace bricks and glass. Garnet is used in sandpaper, water filtration, water jet cutting and as a replacement for silica in sand blasting.

Tiomin then hopes to test-market the concentrates in the first quarter of 1994. Should marketing prove successful, Tiomin envisions building a full-scale dredging operation which would employ 50-60 people and process 13 million tonnes of sand per year.

Unlike many other mining operations, heavy mineral sands are relatively benign in terms of their effect on the natural environment. Granted, there is some disturbance of the local topography, but once the heavies are removed, the sand is replaced, recontoured to its original state and revegetated. To waylay any additional fears, Lennox-King said the company plans to establish a 200-metre environmental buffer zone around the foreshore and the river. He added that the company has no plans to mine the offshore deposits. Although new to the Canadian mining scene, mineral sands are big business in South Africa and Australia, attracting such well-known players as RTZ, BHP and Dupont. Including titanium pigment and zircon, the mineral sands industry generated revenues of US$5.8 billion in 1990.