ELECTRICITY IN CEMENT MILLS
CD 1966075 E&MP33.002
The cement mills of this country are practically 100% electrified and the operations of quarrying, crushing, pulverizing, calcining and repulverizing require about 18 kw. hours per barrel of cement produced.
The annual product is 177 million barrels or enough to make a block of concrete a mile square and 200 ft. high.
The cement kiln, a rotating cylinder often 12 feet in diameter by more than 200 ft. in length, weighs from 400 to 600 tons and is rotated at about two-thirds of a revolution per minute.
In this, the largest piece of rotating machinery in any industry, the powdered stone, dry or mixed with water, is subjected to a heat of 2900ºF. which calcines the mixture to a uniform compound in the form of cement clinker. This product when pulverized to flour is portland cement.
Original Caption by Science Service