The ore and mineral are made up of metal and sulphide mineral and scarce , expensive metallic elementmineral.
矿石矿物主要由金属硫化物矿物及稀有、贵金属元素矿物组成。
2
Se is a kind of scarce and scatter element, and it is very low-grade ore in mineral.
硒是一种稀少而又分散的元素,矿石中其品位一般都很低。
3
Tobacco is an important economic crop, and nitrogen is essential mineralelement. Studies on carbon and nitrogenous metabolism of tobacco have important action on tobacco production.