The vertical tower on the right holds cement powder. The edge of a large, triangular hopper is visible on the far right. That hopper holds different kinds of rock, which are mixed according to the customer's order. It travels up the angled conveyor belt, and is dumped into a cement mixer parked under the tower.
Water is added, and the tower releases cement powder into the mixer. This process is controlled by a computer.
Different uses require either large or small rocks, and different liquidity. When the cement is to be run through a pump, smaller rocks and a runnier mix are required(called "pump mix").
The cement mixer(truck) on the left was just filled under the tower on the right(the "plant"). The driver is now washing the truck down. The truck must be washed off immediately after done pouring cement, or it will harden on the equipment during the drive back to the dispatch center. (date: 2001-05-19)