|Monthly Tech-Tip |
Alternate Names: GK129
Description: White Firing Bentonite
GK 129 bentonite combines a low iron content with a high cation exchange capacity. This combination allows high plasticity while retaining excellent fired color. In detergents, GK 129 is an ideal ion exchange builder, while in liquid soaps it imparts thixotropy and smooth consistency.
Before using this material compare it with other white burning bentonites with respect to fine specking and plasticity. In addition, it should be compared to regular microfine bentonites to be sure that the extra cost and greater amount needed are justified by the fired results.
Typical physical properties data sheet TD-100
G.E. Brightness (% MgO) 80
Moisture (% Max.) 10
Swelling, ml (2 g in 100 ml dist water) 16
pH (10% solids, dist water) 7.0
Screen analysis: % thru 100 mesh 98
Cation Exchange Capacity (C.E.C.) meq./100 grams 80
Bentonite can make a clay body instantly plastic, only 2-3% can have a big effect. It also suspends slurries so they don't settle out and slows down drying.
Clays that are not kaolins, ball clays or bentonites. For example, stoneware clays are mixtures of all of the above plus quartz, feldspar, mica and other minerals. There are also many clays that have high plasticity like bentonite but are much different mineralogically.
|By Tony Hansen|
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