Chapter 44 

 OCEAN-BOTTOM MINING TECHNOLOGY 



J. Leslie Goodier 

 Marine Mineral Technology Center 

 Tiburon, California 



AIRLIFT EXPERIMENT 



General Description 



In the airlift method of mining on the ocean floor, a recovery pipe line is suspended from 

 a surface craft to the seafloor (Fig. 164), and compressed air is injected into a manifold loca- 

 ted on the recovery pipe some distance above the foot or shoe of the pipe (Fig. 165). The air 

 pressure just exceeds the water pressure at the point of air entry into the manifold (Fig. 166). 

 The water above the point of entry of the air into the pipe becomes an aerated froth. This re- 

 duction in density in the upper section of the pipe results in a pressure differential and result- 

 ing water- sediment flow into the base of the recovery pipe. This flow has such velocity that 

 solids are raised to the surface, where they are discharged into recovery barrels. 



SURFACE CRAFT 



BARGE 



NODULES OR SAND 



INTAKE SHOE 



OCEAN BOTTOM 



Fig. 164 Air lift method of recovering material from 

 the ocean bottom 



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