加拿大砂金采选技术

根据1989年在国外期间参加的两次研讨会,以及对育空地区砂金产地的现场考察,归纳分析了加拿大砂金采选技术。200多座家庭式生产经营的中、小矿山,构成育空地区和全加拿大砂金产量的大部分。采选技术特征主要为:普遍应用以推土机和格条溜槽为主要设备的陆上可移式采选厂,重视生产勘探和剥离与选择性开采,筛洗与选收工艺设备因矿而异,尾砂处置和土地复垦法规化与正常化,劳动生产率甚高但资源回收率一般,为提高全年生产作业率而提前解冻和剥采等。值得借鉴的新技术和趋向主要有:永冻层内砂金矿的冬季无支护坑采;通过降低筛分粒度和施加各种振动,改善溜槽作业过程和指标;运用金的放射性同位素示踪,检测砂金洗选回收率和各粒级的金回收率;因黄金市场和生产要素变化,出现了陆上可移式采选厂逐渐取代采金船的趋向。

The mining art and ore dressing of alluvial gold in Canada

According to a couple of international seminars attended by the author of this paper and his on-the-spot investigation of alluvial gold fields at Yukon District of Canada in the year of 1989, an analysis and summary of the mining art and ore dressing of alluvial gold in Canada were made by the author himself.The big majority of alluvial gold in Yukon and even all over Canada were from over 200 small or medium-sized household style mines. Their mining art and ore dressing were characterized by the facts, such as the common use of portable concentration plant in which the bulldozer and grizzly were the principal equipments; the great attention to be paid to geological exploration, stripping and selective mining; the use of different equipments for screening or washing as well as selective recovery in different mines; the regularization and normalization of tailing disposal and land recultivation; the high labor productivity with mediocre recovery of natural resources; the thawing and stripping before due date for the purpose of raising productivity etc.There are some new techniques or trends worthy to be used for reference, such as the unsupported mining of alluvial gold ore at permafrost horizon in winter; the improvement of laundering operation and index through reducing grain size of screening and applying various shakings; the application of radiant isotop of gold for tracing the washing recovery of various sized alluvial gold; the trend of replacing dredger with portable plant due to the variations of gold market and essential factors of production etc.