雅思写作最新范文：砖块的制作

The process by which bricks are manufactured for the building industry can be outlined in seven consecutive steps. First the raw material, clay, which was just below the surface of soil in certain clay-rich areas has to be dug up by a digger.

Then the lumps of clay are placed on a metal grid in order to break up the big chunks of clay into much smaller areas, which fall through the metal grid onto a roller, whose motion further segregates the bits of clay. Sand and water are added to make a homogenous mixture, which is then either formed in moulds or cut into brick-shaped pieces by means of a wire cutter.

Those fresh bricks are then kept in a drying oven for at least 24 and a maximum of 48 hours, several dozens if not hundreds of bricks at a time. The dried bricks are then transferred to a so-called kiln, another type of high temperature oven. First they are kept at a moderate temperature of 200 ℃ -1300 ℃ . This process is followed by cooling down the finished bricks for 48 to 72 hours in a cooling chamber.

Once the bricks have cooled down and have become hard, they get packaged and delivered to their final destination, be it a building site or storage.