Rock crushing is a process used in the construction, mining, and aggregate industry. As the name suggests, it involves breaking down rock into fine, small pieces. The process usually involves several major pieces of equipment. A loader loads the crusher with the large pieces of rock. The crusher cannot crush boulder sized stone. The optimal size is about that of a basketball. There is a crusher that crushes the rock into smaller sizes and feeds the crushed material into another machine called a rock screener. The job of the screener is to size the stone into piles of different sizes. There are generally three sizes of stone produced. One is 1-2″ stone, another is commonly called crusher run and another is ¾” gravel. Click http://www.AimixJawCrushingMachine.com to know more specifications about the working principle of stone crushing machine.
There are a number of factors which influence the crushing process. Some of the factors affecting crushing ratio are hardness, material resistance strength, size, shape, density and humidity.There are some external factors too such as the interaction and distribution of materials when crushing is conducted.
In crushing, the external force has to be great to overcome the binding force between the rock particles. The structure of crystals in the rock determines how strong the cohesion is in the rock. Visit the website of Aimix Machinery Co., Ltd. to get more information about stone crusher.
There are three stages.
(1) Splintering stage: where energy absorption takes place and the rock is crushed in a few large pieces.
(2) Crushing stage, where large pieces are further crushed
(3) Compaction stage, where sheet pieces are broken. This stage produces small chucks.
Rocks are crushed on construction sites and in quarries. Rocks are completely crushed on demolition and recycling sites. Excavated rocks on jobsites that may otherwise be regarded as a waste product can be turned into profit with crushing. Crushed rock can later be used in concrete, in the construction of roads, as fill material in building foundations, for erosion control, as driveways, to bed piping for underground utilities, in asphalt foundations under pavers, and in landscaping.
Often not realized by most people, crushed rock is used as a foundation under concrete slabs, under asphalt in all roads and highways and is an integral component of any type of construction. Many excavation companies that excavate rock also have a portable rock crusher to crush the excavated rocks on the jobsite. Excavated rock on a jobsite should not be discarded as it can always be turned into a useful product.
Crushing rock on the jobsite saves money in two ways. Crushed rock is always in demand on jobsites. If the rock is crushed onsite, there is no need to purchase crushed rock from a quarry or go to the expense of hauling rock onto the jobsite for concrete and asphalt. If the product is used onsite, there is also no need to haul off the excess. It is also a more environmentally friendly to use onsite product.
There are several different machines which crush rocks. Some of the crushers include jaw crushers, cone crushers, impact crushers and roller crushers. Mostly, rock or raw material is inserted into these machines through the hopper on top. The crushed material comes out from an opening at the bottom of the machine.
New varieties of machines offer crushing on-site which offers increased convenience to contractors. They also have higher efficiency and a wide range of compression strengths.
Article Source: http://EzineArticles.com/7449077