Canadian zeolites

By John Ollett
Published: Tuesday, 03 July 2012

Canadian Mining Inc.’s Sun Group project in British Columbia, Canada, is looking to exploit zeolites, a group of 48 natural minerals whose use increased dramatically during the 20th Century. Zeolites’ benefits lie in their adsorption and cation exchange capacity (CEC), which results from their crystalline structure.

Canadian Mining Inc.’s Sun Group project in British Columbia, Canada, is looking to exploit zeolites, a group of 48 natural minerals whose use increased dramatically during the 20th Century. Zeolites’ benefits lie in their adsorption and cation exchange capacity (CEC), which results from their crystalline structure.

This structure is different for each zeolite mineral and is based on a three dimensional network of SiO4 tetrahedra. Due to this structure, zeolites can absorb a high volume of water - without a change in structure - as well as adsorbing heavy metal ions or other ions, including mercury and ammonium.

Run of mine zeolites, with a CEC of 100 or less, can be used for their high degree of hydration and ability to absorb odours in a variety of agricultural and composting applications. Zeolites can also be used for the adsorption of heavy ions, but must have a high CEC, of 120 or above, and can be more expensive due the extra processing required.

The global zeolites market is 3.5m tpa, according to the US Geological Survey (USGS), with China supplying up to two thirds of that total. Prices for low CEC zeolites oscillate around the $50/tonne mark, which encourages local, rather than international, supply.

Geology & mineralogy

The Sun Group zeolites in British Columbia are located in an area, indicated as Cenozoic Sedimentary rock, that is a Quaternary glacial deposit that was oriented through the claims boundary as the glacier progressed south. Although the glacier was responsible for the erosion of material overlying the resource in some areas, as the glacier retreated, the material that had been carved from the valley was deposited as a layer of glacial till, burying the resource to a greater degree in the trough of the valley.

The main zeolite mineral at the deposit is clinoptilolite, which is formed from the deposition of volcanic ash into an aquatic environment, such as the ancient lake located within the claims boundary.

Two historical studies have been completed on the deposit, which found that the resource has an average thickness of 19 metres and a strip ratio of 1.82:1 ranging up to 3:1 as the deposit dips. According to studies, which are not NI 43-101 compliant, there is a resource of 46.6m tonnes at a cut-off of 100 CEC. This includes indicated, measured, and inferred resources.

This grade would be ideal for supplying the value-added markets, but Canadian Mining is looking to also exploit the sub-100 CEC zeolites. The size of the sub-100 CEC deposit is probably equivalent in size to the historical estimate, Ray Paquette president of Canadian Mining, told IM.

“I am looking at a deposit that is in the neighbourhood of 100m tonnes ... a lifetime of income for this particular company,” he said.

The project

The Sun Group project is located near the town of Princeton, British Columbia, and has been previously explored for its zeolite potential.

The company is hoping to complete its NI 43-101 by September 2012, when it will also have completed a 10,000 tonne bulk sample for distribution to customers, after which the company will look to begin mining of the property, Paquette told IM.

The bulk sample will be distributed to potential clients in the local area, which will help to grow the business for the first year. After that, the construction of a mill will help the company to produce value-added zeolites of above 120 CEC that it will look to distribute further afield, while maintaining the local market.

The mine will be an open-pit mining operation similar to a sand quarry, Paquette said. It has about 10 metres overburden and the depth of the deposit is unlikely to be more than 150 metres, he added. The initial crushing and screening will be done on-site before it is shipped to customers

 
 
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The mine will be a 12-month operation since it is far enough south not to be hampered by the extreme Canadian snowfall common in winter. It could produce up to 50,000 tpa but will start with smaller production for local markets.

The markets

The main two markets for zeolites remain the value-added markets, involving molecular sieving, and the markets that require a lower-grade CEC product, such as agriculture and composting.

“We have a huge local market that requires the use of zeolites below 100 CEC ... within 100 km of our deposit that I can service out of run-of-mine material, crushed and screened out to a specific size,” Paquette told IM.

These markets will include wineries, organic orchards, and communities that are trying to do biosolids composting, which can be supplied by trucks straight from the mine site, which borders a major highway, for a cost of between $20-45/tonne, Paquette added.

This will be the main focus of the mine for the first year. “For year two, I would like to build a mill that will facilitate value-added products by being able to screen specific sizes that are geared for specific markets,” Paquette said.

Due to their extra cost and higher prices, these value-added products could be shipped abroad to Japan or South Korea and be used in the cleanup of radioactive waste or the filtration of mercury. Test samples have already been sent from the Sun Group project to Japan and exceeded the value-added requirement of 120 CEC.

Asian markets are often supplied out of China, but a common problem is that the mineral supplied is often of a lesser quality than the initial sample. This has led certain companies to explore other options for the supply of zeolites above 120 CEC.

Prices for these value-added zeolites range between $150-275/tonne for granulated sand-sized zeolite up to micronized powder for use in cementing or as an absorbent in molecular sieves, Paquette said.

“Those are the markets that, as we grow, we hope to open the door to,” he added.