PLACER GOLD DIGGING AND SORTING METHOD AND DIGGING AND SORTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To automatically separate placer gold, sand, etc., by sucking a mixture of the sand contg. placer gold and water, accelerating the mixture by a fluid jet and applying gravity concentration to the flowing mixture. SOLUTION: When a flow is generated in a transfer pipe 4 as shown by the arrow 13, an upward flow is also generated in a sand lifting pipe 2 through a connecting pipe 8 as shown by the arrow 14. When the flow at a speed of 3 m/sec is generated in the transfer pipe 4, a flow at the same speed is generated in the sand lifting pipe 2, and the sand and water are sucked from the lower end of the pipe 2 in the amt. corresponding to the flow rate. Separation boxes 5, 6 and 7 are connected in series at regular intervals in the transfer pipe 4. Since the cross-sectional area in the boxes 5, 6 and 7 is larger than that of the transfer pipe 11, the flow velocity is lowered in proportion to the cross-sectional area, and sand, etc., are deprived of buoyancy. Consequently, the placer gold high in sp.gr. are settled first, and the materials higher in sp.gr. are successively settled and separated.