(1) The Definition and Application Range of Gravity Concentration Gravity concentration is an ore beneficiation methods making use of the difference of the mineral particles to be separated in relative density, granularity and shape and the difference of moving speed and direction of them in the media such as water, air or other types of liquid with relatively big density to separate the mineral particles. Gravity concentration is one of the most widely used ore beneficiation methods and it is mainly used for deal with materials with big density difference. It is not only the most important methods used for separating coal, but the traditional methods for separating metal ores such as gold, tin and tungsten, and also it is widely used for dealing with the rare metal ores such as titanium, zirconium, calcium, vanadium, niobium, tantalum and molybdenum. Gravity concentration can also use for separating iron ore and manganese ore, and also used for dealing with some non-metallic ores such as asbestos, diamond and kaolin. In addition, gravity concentration methods is also used for the dehydration, classification, concentration and dirt retention work, which are indispensable in the ore beneficiation plant and coal dressing plant. (2) The Purpose and Technical Classification of Gravity Concentration The main purpose of gravity concentration is to separate the ore particles according to their density. For this reason, in the concentration process, we should concentrate our wisdom to create favorable conditions to reduce the influences of the granularity and shape of the ore particles on the separation result, to make sure the density difference of the ore particles takes the leading role in the concentration process. According to the movement modes of the media and the working purpose, gravity concentration can be divided into water conservancy concentration, dense media separation, jig dressing, shaking table concentration, spiral chute separation and ore washing. According to the different media used, it can be divided into wet type gravity concentration and wind (wet type) gravity concentration. (3) The construction waste crusher equipment Used for Gravity Concentration To strengthen the concentration effect of the fine particles, in the gravity concentration process, many ore beneficiation machines will be used, such as spiral chute, centrifugal machine and hydro cyclone.