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 system therefor

摘要

A placer gold separating method includes subjecting placer gold- and gold ore-containing sand and gravel layers accumulated on the bottom of the water of a river and placer gold- and gold ore-containing sand and gravel layers formed deep in the ground to excavation or suction excavation by utilizing a water pressure difference. This causes a mixture of the excavated or suction excavation placer gold- and gold ore- containing sand, gravel and water to flow horizontally by the action of a pressure fluid. The placer gold and gold ores are separated by utilizing a specific gravity difference while the mixture is flowing. A placer gold mining boat used to practice this method is provided thereon with a combination of a suction excavation component, a mixture transfer component, a component for separating placer gold by utilizing a specific gravity difference, and a component for discarding the remaining mixture from which the placer gold has been separated. A placer gold separating method is characterized by causing a mixture of placer gold and gold ores or pulverized gold ores and water to flow in a metallic cylinder. A magnetic field is generated by a magnetic field generating component provided on an outer circumferential surface of the metallic cylinder, and the placer gold in the mixture is magnetically deposited on the inner surface of the metallic cylinder, whereby the placer gold is separated.