白银选矿厂自1959年投产以来,铜精矿品位一直在18％以下。通过贯彻冶金部几次选矿技术座谈会精神,1978年以来,各项技术指标有所提高(见下表)。 Since the silver concentrator was put into operation in 1959, the grade of copper concentrates has been below 18%. By implementing the spirit of several mineral processing technology symposiums held by the Ministry of Metallurgy, various technical indicators have been raised since 1978 (see the table below).