placer mining

基本解释

This primitive form of placer mining is still used in some places for panning gold.
这种原始的砂矿开采形式至今还在一些地方用来淘金。
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Mechanized placer mining, with special devices for washing and separating waste from valuable minerals, is used in productive alluvial deposits.
机械化砂矿开采用于含矿量丰富的砂矿床．利用专门设备来淘洗、分离废物与有用矿物。
In conducting coastal open air placer mining or shore-based well drilling to exploit seabed mineral resources, effective measures must be taken to prevent pollution to the marine environment.
露天开采海滨砂矿和从岸上打井开采海底矿产资源，必须采取有效措施，防止污染海洋环境。

Dines likes, among others, mining concerns Placer Dome (nyse: PDG - news - people ) and Hecla Mines (nyse: HL - news - people ).
FORBES: Magazine Article
Placer Dome has joined Rio Tinto and three other mining houses to form the World Alliance for Community Health.
ECONOMIST: Companies and health