Second, a quarry must receive appropriate zoning and permits. Throughout the operation of the quarry, mining companies must follow laws governing safety and the environment. Next, dozers remove the top layer of grass, dirt and rock called overburden. Near the rocks outer edge, long holes are drilled downward and loaded with explosive. The rock is blasted to loosen and break the rock into pieces.
Workers follow special safety precautions, rules and regulations when blasting occurs in a quarry.
A haul truck transports rock to the crushing plant. Rocks can be crushed into many different sizes of aggregate with a machine called a jaw crusher. The machine works like a jaw by crushing and chewing large rocks into small rocks. It is usually stationed in a permanent place at the quarry. Another kind of machine, called a portable crusher, can be moved to where the rocks are.