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EP Kaolin

Plastic White Firing Kaolin

Alternate Names: EPK, Edgar Plastic Kaolin, EPK Kaolin

Oxide Weight232.50
Formula Weight272.92
If this formula is not unified correctly please contact us.
PCE - Pyrometric Cone Equivalent 35

A secondary water washed kaolin mined in Florida. It is fairly plastic and very white firing compared with most other American kaolins. It has excellent casting properties. It is not plastic enough for throwing bodies, thus it should be augmented by a more plastic kaolin or by a plasticizer like bentonite or hectorite.

EPK is considered by many to be the best North American kaolin for use in suspending glazes as it tends to produce a smooth thixotropic slurry. 15-20% will normally make the glaze gel slightly, thus when a piece is immersed in the slurry and removed it drips very little and the wet glaze layer stays in place for the time it takes to dewater. Since EPK is very close to theoretical kaolin chemistry, it will subsitute for any other kaolin that can make the same claim (e.g. Pioneer).

This material is mined and processed in Edgar Florida. It is extracted hydraulically (a high pressure stream of water is used to wash the clay/sand mix from the bank into a small lake). The slurry is pumped from the bottom and transported to vibrating screens that separate out the sand and grade it into sizes. The clay that passes the screens is pumped into a pond and settled with the aid of a flocculant. The slurry is then dried and the flocculant neutralized. The main product at this mine is high quality white sand, the clay is a byproduct. The company is confident that there are reserves for the next hundred years or more and the quality will be constant throughout the life cycle of the deposit.

A 70:30 mix of EPK:Nepheline Syenite has gone to mush

This was plastic and moldable two days ago, now it is incredibly sticky. It is being compared with 5 other kaolin:nepheline mixes, none of them have reacted in this way.

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In Bound Links

By Tony Hansen

XML for Import into INSIGHT

<?xml version="1.0" encoding="UTF-8"?> <material name="EP Kaolin" descrip="Plastic White Firing Kaolin" searchkey="EPK, Edgar Plastic Kaolin, EPK Kaolin" loi="0.00" casnumber="95077-05-7"> <oxides> <oxide symbol="CaO" name="Calcium Oxide, Calcia" status="" percent="0.180" tolerance=""/> <oxide symbol="MgO" name="Magnesium Oxide, Magnesia" status="" percent="0.100" tolerance=""/> <oxide symbol="K2O" name="Potassium Oxide" status="" percent="0.330" tolerance=""/> <oxide symbol="Na2O" name="Sodium Oxide, Soda" status="" percent="0.060" tolerance=""/> <oxide symbol="P2O5" name="Phosphorus Pentoxide" status="" percent="0.240" tolerance=""/> <oxide symbol="TiO2" name="Titanium Dioxide, Titania" status="" percent="0.370" tolerance=""/> <oxide symbol="Al2O3" name="Aluminum Oxide, Alumina" status="" percent="37.360" tolerance=""/> <oxide symbol="SiO2" name="Silicon Dioxide, Silica" status="" percent="45.730" tolerance=""/> <oxide symbol="Fe2O3" name="Iron Oxide, Ferric Oxide" status="" percent="0.790" tolerance=""/> </oxides> <volatiles> <volatile symbol="H2O" name="Water" percent="1.400" tolerance=""/> <volatile symbol="LOI" name="Loss on Ignition" percent="13.200" tolerance=""/> <volatile symbol="SO3" name="Sulfur Trioxide" percent="0.210" tolerance=""/> </volatiles> </material>

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