Portland Cement

Chemistry

CaO	62.275
MgO	2.215
Al2O3	7.549
SiO2	22.647
Fe2O3	2.113

Volatiles

LOI

3.200

Miscellaneous

Family: Other
Region: None
Mined At: Unspecified
Raw Mineral: No
Generic: No

Notes

Manufactured using limestone and shale. Powder is mixed and fired in a rotary kiln to near-stoneware temperatures. The clinker is finely ground to produce a grey powder that reacts with water to form a hydrous calcium silicate with some CaO left over.

Acids do attack cement however as soluble materials are removed less reactive remaining materials are quite stable.

Note

(Richard Willis)

A relatively high-temperature calcinated mix of clay and lime which hardens quickly after wetted with water and left to air-dry. Unlike most “natural” clay cements, however, Portland’s bonding deteriorates under time, stress and weathering. Like all clay cements, Portland, behaving as a calcined calcareous earth, will fuse readily when fluxed and will melt at much lower temperatures than its required high calcinating temperatures. A simple brown glaze, for example, can be obtained at 900º ;C from a thick solution comprising equal parts of Portland and hydroboracite or minium.
typical analyses of compositions, after calcinated at 1300-1500ºC
“limestone”; 52% lime, 3% silica, 1% slumina, 0.5% iron, 0.5% magnesia, 42% burned away
“chalk”; 54% lime, 1% silica, 0.5% alumina, 0.2% iron, 0.3% magnesia, 43% burned away
“cement rock”: 43% lime, 11% silica, 3% alumina, 1% iron, 2% magnesia, 36% burned away
“clay”: 1% lime, 57% silica, 16% alumina, 7% iron, 1% magnesia, 14% burned away
“slag”: 42% lime, 34% silica, 15% alumina, 1% iron, 4% magnesia, 0% burned away

Suppliers

Generic

Authors

Tony Hansen (Owner)

XML

<?xml version="1.0" encoding="UTF-8"?>
<material name="Portland Cement" descrip="" generic="0" rawmineral="0" searchkey="" loi="3.20">
<families>
<family name="Other"/>
</families>
<oxides>
<oxide symbol="CaO" name="Calcium Oxide, Calcia" status="U" percent="62.275" tolerance=""/>
<oxide symbol="MgO" name="Magnesium Oxide, Magnesia" status="U" percent="2.215" tolerance=""/>
<oxide symbol="Al2O3" name="Aluminum Oxide, Alumina" status="" percent="7.549" tolerance=""/>
<oxide symbol="SiO2" name="Silicon Dioxide, Silica" status="" percent="22.647" tolerance=""/>
<oxide symbol="Fe2O3" name="Iron Oxide, Ferric Oxide" status="" percent="2.113" tolerance=""/>
</oxides>
<volatiles>
<volatile symbol="" name="" percent="3.200" tolerance=""/>
</volatiles>
<suppliers>
<supplier name="Generic" country="" url="" label=""/>
</suppliers>
<notes>
<note>Manufactured using limestone and shale. Powder is mixed and fired in a rotary kiln to near-stoneware temperatures. The clinker is finely ground to produce a grey powder that reacts with water to form a hydrous calcium silicate with some CaO left over.

Acids do attack cement however as soluble materials are removed less reactive remaining materials are quite stable.</note>
<note>A relatively high-temperature calcinated mix of clay and lime which hardens quickly after wetted with water and left to air-dry. Unlike most &#147;natural&#148; clay cements, however, Portland&#146;s bonding deteriorates under time, stress and weathering. Like all clay cements, Portland, behaving as a calcined calcareous earth, will fuse readily when fluxed and will melt at much lower temperatures than its required high calcinating temperatures. A simple brown glaze, for example, can be obtained at 900&ordm
;C from a thick solution comprising equal parts of Portland and hydroboracite or minium. 
typical analyses of compositions, after calcinated at 1300-1500&ordm;C 
&#147;limestone&#148;; 52% lime, 3% silica, 1% slumina, 0.5% iron, 0.5% magnesia, 42% burned away 
&#147;chalk&#148;; 54% lime, 1% silica, 0.5% alumina, 0.2% iron, 0.3% magnesia, 43% burned away 
&#147;cement rock&#148;: 43% lime, 11% silica, 3% alumina, 1% iron, 2% magnesia, 36% burned away 
&#147;clay&#148;: 1% lime, 57% silica, 16% alumina, 7% iron, 1% magnesia, 14% burned away 
&#147;slag&#148;: 42% lime, 34% silica, 15% alumina, 1% iron, 4% magnesia, 0% burned away 

</note>
</notes>
</material>

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