placer mining
noun/ˈpleɪsə maɪnɪŋ/
/ˈpleɪsər maɪnɪŋ/
[uncountable] (North American English)- the process of getting gold or other valuable minerals, usually from a river or lake, by washing away the sand that surrounds it
砂矿开采：通常是从河流或湖泊中洗净金矿或其他有价值的矿物的过程，方法是洗掉周围的沙子 - placer mining operations
砂金采矿作业
- placer mining operations