The technology of mineral processing of gold ores and extracting process after gold soaking were summarized from the acts of gravity concentration,flotation,cyanidation process and cyanide free process,especially the pretreatment of refractory gold ores.
从重选、浮选、氰化及非氰化无毒提金法等方面简述了黄金的选别技术以及浸出金后的提金工艺及其发展,特别介绍了难处理金矿的预处理技术。
This analysis shows that the higher the success rate of sex selection of the second-baby,the higher the sex ratio at birth and the bigger the absolute margin between two kinds of family planning policies,but the relative margin between them is stable.
研究表明,第二胎成功性别选择率越高,出生性别比就越偏高,两种生育政策下的出生性别比绝对差值就越大,相对差值较稳定。
