PLACER GOLD MINING METHOD, PLACER GOLD MINING BOAT USED IN THIS METHOD, PLACER GOLD DIGGING AND SEPARATING METHOD AND SYSTEM THEREFOR, AND PLACER GOLD SEPARATING METHOD AND SYSTEMTHEREFOR

摘要

A placer gold separating method comprising subjecting placer gold- and goldore-containing sand andgravel layers accumulated on the bottom of the water of a river and placergold- and gold ore-containingsand and gravel layers formed deep in the ground to excavation or suctionexcavation by utilizing a waterpressure difference, causing a mixture of the excavated or suction excavatedplacer gold- and goldore-containing sand, gravel and water to flow horizontally by the action of apressure fluid, and separating theplacer gold and gold ores by utilizing a specific gravity difference while themixture is flowing; and asystem for this method. A placer gold mining boat used to practice this methodand provided thereon with acombination of a suction excavation means, a mixture transfer means, a meansfor separating placer gold byutilizing a specific gravity difference, and a means for discarding theremaining mixture from which theplacer gold has been separated. A placer gold separating method characterizedby causing a mixture ofplacer gold and gold ores or pulverized gold ores and water to flow in ametallic cylinder, generating amagnetic field by a magnetic field generating means provided on an outercircumferential surface of themetallic cylinder, and magnetically depositing the placer gold in the mixtureon the inner surface ofthemetallic cylinder, whereby the placer gold is separated.