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Plainsman Red Fireclay

Oxide Analysis Formula
BaO 0.30% 0.01
CaO 0.50% 0.05
MgO 0.20% 0.03
K2O 0.30% 0.02
Na2O 0.10% 0.01
P2O5 0.10% -
TiO2 1.00% 0.08
Al2O3 16.60% 1.00
SiO2 66.00% 6.75
Fe2O3 6.90% 0.26
MnO 0.10% 0.01
LOI 7.90%n/a
Oxide Weight 565.92
Formula Weight 614.46

Notes

This is a material being developed by Plainsman as a more suitable subsitute for Newman firelcay than FireRed (samples should be available in July 2003). FireRed is a 50:50 mix of a non-plastic red fireclay and a plastic red stoneware with 15% of a highly bentonitic and iron speckled ball clay. This material differs from FireRed in that:
-it is ground finer reducing the coarser particle sizes up to 60 mesh, but it is actually coarser in the finer particle size range
-it employs the red fireclay only with 20% of a cleaner ball clay

This mix has a lower iron content than Newman so we will either recommend an addition or add it here.

Red Fireclay is ground to 60 mesh and is finer than Newman clay in the +65 mesh range
(thus there are none of the larger impurity grog-like particles common in Newman).
However in the minus 65 mesh range this material has a much better distribution of particle sizes.

In a test body containing 50% Newman, 25 feldspar, 15 ball clay and 10 silica the following was found:

-The Newman version felt smoother on the potters wheel with scattered larger
particles
-Both generated about the same amount of slip during throwing.
-The Newman version is brighter red in the raw state and messier to work with.
-The Newman version has up to 1% higher drying shrinkage yet its drying
performance (resistance to cracking) is a little better.
-The Newman version is not quite as plastic.
-The Newman version had significantly lower dry strength (this body was quite
non plastic, thus more than 15% ball clay is needed).
-The Newman version fired significantly redder but when 1.5% iron was added to the Plainsman Red Fireclay and the test rerun the fired color was the same.

Related Information

Links

Materials Fire-Red
Materials Newman Red Clay
Materials M2 Red Stoneware
Materials A2 Ball Clay
Materials Saint Rose Red
Materials Fireclay
Typecodes Clay Other
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.
Typecodes Fireclay
Fireclays are non-kaolin non-ball clay materials similar to stoneware clays but lacking fluxing oxides. Many fireclays have a PCE of 28 or more.
Typecodes Fireclay
Fireclays are non-kaolin non-ball clay materials similar to stoneware clays but lacking fluxing oxides. Many fireclays have a PCE of 28 or more.

Data

Sieve Analysis Dry +48 mesh: 0-0.1% 48-65: 0-0.3 65-100: 0.2-1.0 100-150: 3.0-5.0 150-200: 6.0-8.0 200-325: 7.0-9
By Tony Hansen
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