1.The dredger could be divided into bucket type and pump suction type. Bucket type dredger is applied for waterways with high percentage of clay and gravels, while pump suction type can only be used for terrains with low percentage of clay and gravel. 2.Iron ore need to be retrieved firstly by magnetic separator if the percentage is high in the raw ore, then gold, diamond,zirconium will be concentrated. 3.The key part for the diamond dredger is pulsating jigger. The deal capacity decide the quantity of jigger. We learn the jigger’s technology from one engineer of South Africa. Now the diamond dredger is widely used in Africa.

Bucket-chain gold dredgers are suitable for placer gold mining in rivers and waterways; they can be used for placer gold mining in lakes and coastal shallows; and they are employed for the re-processing of historical tailings or old mining areas to extract residual gold particles. The dredger is composed of several gravity concentrators.The concentration ratio could reach as high as 1:1000,and the recovery efficiency about 90% after series of separating.