Bentone MA

Glaze Suspender, Hectorite

Chemistry

CaO5.500
Li2O1.300
MgO22.700
Na2O3.200
Al2O30.800
SiO253.200
Fe2O30.300

Volatiles

LOI12.700

Links to Other Materials

Miscellaneous

Notes

Bentone grades HC, CT, EW are used as rheology modifiers in glazes.

Macaloid is an off-white flaky powder used primarily as a glaze suspender made from hectorite montmorillonitic ore (see Hectorite). It tends to suspend and harden the dried glaze while not extending the glazes drying time, as is the case with CMC gum. Thus it is common to use Macaloid and CMC together to control drying time, suspension and glaze hardness.

Macaloid is valued for its long-time suspending properties which helps prevent uneven settling of material particles which have differing specific gravities (i.e. stain particles tend to be much heavier and settle first).

Macaloid is lower in iron than bentonite and thus is valued as a plasticizer in porcelain bodies. Like bentonite, it increases water requirements and can be used in similar amounts.

To get maximum benefit from Macaloid, it should be mixed thoroughly into the water with a power blunger (for hours if possible) before adding the other dry ingredients.

C.E.C.: 78 me/100 gm
Principle Exchange Ion: Na
pH (5% solids slurry): 8.5
Hectorite Content: 90%
Minus 50 mesh: 90%
Minus 325 mesh: 99.5%
Surface Area: 600 sq. meter/gram
Bulk Density (not compacted): 0.24-0.37 g/cc


Suppliers

Authors

XML

<?xml version="1.0" encoding="UTF-8"?>
<material name="Bentone MA" descrip="Glaze Suspender, Hectorite" generic="0" rawmineral="0" searchkey="Macaloid" loi="11.70">
<families>
<family name="Clay Other"/>
</families>
<oxides>
<oxide symbol="CaO" name="Calcium Oxide, Calcia" status="" percent="5.500" tolerance=""/>
<oxide symbol="Li2O" name="Lithium Oxide, Lithia" status="" percent="1.300" tolerance=""/>
<oxide symbol="MgO" name="Magnesium Oxide, Magnesia" status="" percent="22.700" tolerance=""/>
<oxide symbol="Na2O" name="Sodium Oxide, Soda" status="" percent="3.200" tolerance=""/>
<oxide symbol="Al2O3" name="Aluminum Oxide, Alumina" status="" percent="0.800" tolerance=""/>
<oxide symbol="SiO2" name="Silicon Dioxide, Silica" status="" percent="53.200" tolerance=""/>
<oxide symbol="Fe2O3" name="Iron Oxide, Ferric Oxide" status="" percent="0.300" tolerance=""/>
</oxides>
<volatiles>
<volatile symbol="" name="" percent="12.700" tolerance=""/>
</volatiles>
<references>
<reference name="seealso" reason=""/>
<reference name="seealso" reason=""/>
</references>
<suppliers>
<supplier name="Elementis Specialities, Inc." country="US" url="http://elementis-specialties.com" label=""/>
</suppliers>
<notes>
<note>Bentone grades HC, CT, EW are used as rheology modifiers in glazes.

Macaloid is an off-white flaky powder used primarily as a glaze suspender made from hectorite montmorillonitic ore (see Hectorite). It tends to suspend and harden the dried glaze while not extending the glazes drying time, as is the case with CMC gum. Thus it is common to use Macaloid and CMC together to control drying time, suspension and glaze hardness.

Macaloid is valued for its long-time suspending properties which helps prevent uneven settling of material particles which have differing specific gravities (i.e. stain particles tend to be much heavier and settle first).

Macaloid is lower in iron than bentonite and thus is valued as a plasticizer in porcelain bodies. Like bentonite, it increases water requirements and can be used in similar amounts.

To get maximum benefit from Macaloid, it should be mixed thoroughly into the water with a power blunger (for hours if possible) before adding the other dry ingredients.

C.E.C.: 78 me/100 gm
Principle Exchange Ion: Na
pH (5% solids slurry): 8.5
Hectorite Content: 90%
Minus 50 mesh: 90%
Minus 325 mesh: 99.5%
Surface Area: 600 sq. meter/gram
Bulk Density (not compacted): 0.24-0.37 g/cc
</note>
</notes>
</material>



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