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El Dorado of Pottery Clay Finally Found!
It has been five years since getting and testing samples of an amazing porcelain-like, clean-burning, highly plastic middle-temperature stoneware raw material from south central Saskatchewan. It is far superior to anything we have now. But, due to mix-ups, it appeared its location had been lost! But coming here to search again has turned up new information and I am quite certain this is the site (at Flintoft, Saskatchewan). Seeing and walking it has confirmed, contrary to the information we had, that the site is highly suitable for extraction (previous mine workings to the left are not shown). And, it is not the only site in the area. The Whitemud clays here are quite different from those in our Ravenscrag quarry, they are so good they obsolete almost everything we have (except perhaps PR3D). On seeing the range and quality, I am beyond excited! There are a lot of ducks that have to be lined up to be able to actually extract from a site like this, but the location has a lot of advantages. The current economic realities will be a powerful motivator to developing Canadian clay sources.
Related Pictures
"Whitemud" clays in dinosaur country of southern Saskatchewan.
These are Cretaceous. Jurassic? 1km straight down.
This picture has its own page with more detail, click here to see it.
This is a "badlands" slope in the Frenchman river valley. The valley exposes the "Whitemud Formation" in many places (clearly visible here part way down on the left). Two surface mines of Plainsman Clays are nearby, in a place where lower-lying rolling hills leave much less over-burden to remove. These materials were laid down as marine sediments during the Cretaceous period. The skeleton of the world's largest T.Rex, dubbed "Scotty", was found 50km east of here (in the layers just above the Whitemuds). Where are the layers of Scotty's ancestors from the Jurassic period? Straight down 1 kilometer! And another kilometer to bedrock!
A Highly Plastic White Burning Kaolinized Sand:
This proves we can have a Canadian kaolin
This picture has its own page with more detail, click here to see it.
This is kaolinized sand from Flintoft, Saskatchewan. It is among clays we are currently rediscovering. This is far more plastic and fires much whiter than our Ravenscrag quarry equivalent. Consider highlights of physical tests to characterize it (data shown lower left):
-Super refractory (thus theoretically pure). The SHAB test bars (lower right from cone 10R and 10 down to 6 oxidation) correspond to the SHAB test results in the chart. Even at cone 10, this has an amazing 19% porosity. With almost zero shrinkage.
-Plasticity: Excellent (notice the texture of the plastic material in the close-up photo on the upper left).
-The DFAC test disk upper right shows perfect drying performance and very low soluble salts.
-White burning: The top bar is reduction-fired yet barely darker than the one below it at the same temperature in oxidation (indicating low iron content).
-Centre-bottom: G1947U clear glaze on it fired at cone 10R.
-Easy-to-access in new and old quarry sites.
I compared this with about 10 other clays in the area, doing the same for all of them, preserving a treasure trove of data for clays we have been overlooking.
An All-Canadian Fine Ball Clay is in Sight!
This picture has its own page with more detail, click here to see it.
On the right is Plainsman A2 ball clay with 35% nepheline syenite added to vitrify it around cone 6 (these bars are fired at cone 2, 4, 5, 6 and 7 - top to bottom). Using our grinding equipment, we can process it to 42 mesh, as we have done since the 1970s. On the left is a Flintoft ball clay (cone 10R top and 10, 9, 8, etc - top to bottom). But this is the raw material, just slaked (not ground). It reaches zero porosity at cone 6 without a feldspar addition (because Mother Nature has added it for us). And the plasticity? This ball clay dry shrinks 9%, it is super plastic, much more than the A2/feldspar mix. While nearby deposits also contain refractory ball clays, this one is truly something special. It enables not just highly plastic vitreous stonewares but it fires white enough to be a potential ingredient in an All-Canadian plastic cone 6 porcelain. In an unexpected turn of events, we now have the opportunity to get this clay in a way that is much easier than expected. We have tested mixing this with PR3D, the best material in our Ravenscrag quarry - together the two can make killer clay bodies!
Whiter Clays and Grinding Capacity:
Two problems solved in one place!
This picture has its own page with more detail, click here to see it.
This is at the Whitemud Resources metakaolin (MK) site midway between Scout Lake and Wood Mountain, Saskatchewan. They mine ore that is separated into kaolin (reject material is silica sand) then dehydroxylated into metakaolin; an SCM (Supplementary Cementing Material), MK itself is a natural aluminosilicate pozzolan. They have a giant plant (the dome is big enough to play soccer in) and are capable of processing an order of magnitude more than we can. The mining face in their quarry appears to have the same layers that we mine in Ravenscrag. But, there are very fortunate differences:
-This deposit is near Flintoft, these clays will be much purer and whiter than what we can get in our Ravenscrag quarry (pending testing, of course).
-We need what is above the coal seam, they need what is below (their garbage is our gold).
-The layers appear to be the same as those in our existing quarry.
-Their grinding plant is capable of micron-sizes and is gigantic.
-Their by-product is silica sand!
-They are working on a mining plan for August extraction.
This is close to a "marriage made in heaven", we shall see. It is certainly going in the direction of enabling us to improve product quality. And hopefully, soon make an all-Canadian porcelain.
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