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Manganese Granular

Manganese, Granular Pyrolusite

Formula: MnO2
Alternate Names: Granular Manganese

In ceramics, it is used primarily in clay and glaze to achieve dark brown or black fired speckle. This is the same material as manganese dioxide powder, it is simply not ground as fine. Typically a 60-80 mesh material is used in amounts around 0.2-0.3%.

Pyrolusite ore is a source of manganese used widely in industry for the manufacture of manganese steel, alkaline batteries, decolorizing glass agents, and in ceramic bodies and glazes. Pyrolusite can contain small amounts of quartz (e.g. 3%) as well as barium compounds (e.g. 2%) and trace amounts of lead (e.g. 0.2%). It is typically about 75% MnO2.

Decomposing manganese granular particles in a buff stoneware causing it to bloat

Decomposing manganese granular particles in a buff stoneware causing it to bloat

A cone 6 stoneware with 0.3% 60/80 mesh manganese granular (Plainsman M340). Fired from cone 4 (bottom) to cone 8 (top). It is normally stable to cone 8, with the manganese it begins to bloat at cone 7. The particles of manganese generate gases as they decompose and melt, these produce volumes and pressures sufficiently suddenly that closing channels within the maturing body are unable to vent them out.

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By Tony Hansen

XML for Import into INSIGHT

<?xml version="1.0" encoding="UTF-8"?> <material name="Manganese Granular" descrip="Manganese, Granular Pyrolusite" searchkey="Granular Manganese" loi="0.00" casnumber=""> </material>

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