... mainly produce:1.Sand machinery: bucket dredger, jet suction dredger, auto-suction and pumping dredger, land crushers, sand making machine, ... machinery: Iron sand dredger with chain and hopper, auto-suction iron dredger, land and water selection devices.3. ... Large dredging machinery: cutter suction dredger, amphibious dredger, drilling sand suction dredger. 4. Rare metal extraction machinery ...