Re: Cement ingredients, Was: cement travel

gettheredesigns <rick@...>

--- In STMFC@..., Anthony Thompson <thompson@...> wrote:

It's important to recognize that limestone and clay provide
nearly the entire content of most cement. Iron is essential but
present in relatively small amounts in normal cement. Calcium sulfate
can come from other minerals than gypsum if gypsum is not economically
available locally.
Good point Tony--the cement plants aren't next to the iron mines.

The following data is from the 1949 Minerals Yearbook published by the Bureau of Mines. This is a list of all materials used in cement manufacture in that year, in short tons.

Cement rock (argillaceous limestone) 12,628,494
Limestone and oyster shells 44,968,739
Marl 722,606
Clay and shale 6,698,408
Blast-furnace slag 847,375
Gypsum 1,543,198
Sand and sandstone 724,624
Iron-bearing materials 346,542
Other materials, including diatomite,
flue dust, coal-tar pitch, red mud and rock,
hydrated lime, tufa, cinders, calcium
chloride, sludge, grinding aids, and
air-entraining compounds 140,999

Total 68,620,985

Cheers, Rick

Join to automatically receive all group messages.