Gravel profile
Gravel: refers to the weathering of rock by the water long-term handling of diameter 2 ~ 60mm of natural aggregate free edges.
Pebble: refers to is weathering of rock by the water for a long time handling and particle size of 60 ~ 200mm no edges and corners of the natural ovoid grain; more than 200 mm who says boulders.
The main chemical composition of gravel is silica, followed by a small amount of iron oxide and trace amounts of manganese, copper, aluminum, magnesium and other elements and compounds. They themselves with different colors, such as red as the iron, the blue copper, purple for manganese, translucent yellow for silica gel chalcedony, jade color with green mineral and so on; due to the different kinds and contents of these pigment ions dissolved silica hydrothermal, thus showing a depth of shade, the changing color pebbles show black, white, yellow, red, green, green color.
Gravel classification
Gravel is a name for the classification of sediments. Often expressed as a symbol G. Rock or mineral debris, with an average particle size of more than 1 mm.
According to the average particle size, and the gravel subdivision into three kinds of boulders, cobbles and fine gravel: average particle size of 1 - 10 mm of that fine gravel; 10 - 100 mm of that coarse gravel; greater than 100 mm, said the boulder. After being consolidated into rock, the gravel is called conglomerate or.

Gravel use
Refining, ordinary two types of characteristics of gravel: Gravel hardness is 7, the proportion of 2.65, the color was milky white, yellow, brown and grey, the gravel has high refractory performance, is the manufacture of glass, refractories, smelting, flux for metallurgy, ceramics, abrasive materials, casting, in the construction of gravel with a strong acid medium erosion resistance ability to producing acid resistant concrete and mortar acid. Especially for the use of water treatment filter material, high strength, sewage interception ability, good acid resistance. Glass, ceramic, enamel, hot bottle, sodium silicate, casting, building materials, grinding, fire, military, communications and other industries is the main raw material.