近年来,国外大部分金属价格不高,因而影响了开发,但是贵金属例外,这可反映在1986年新项目和扩建规划活动上,西方国家大约有90项金矿项目在进行,其它只有50项。另一方面,采矿和选矿不景气现象,也给现有厂矿继续降低生产费用带来压力,经济压力也是加强研究和开发工作的其中一个原因。 In recent years, most overseas metals prices have not been high, thus affecting the development. However, with the exception of precious metals, this can be reflected in the 1986 new projects and expansion planning activities, with about 90 gold projects in the western countries underway and 50 others . On the other hand, the sluggish mining and dressing phenomenon has also put pressure on existing factories and mines to continue to reduce their production costs. Economic pressure is also one of the reasons for strengthening R & D.