Waste Printed Circuit Boards (PCBs) are worthy very much to recycle, because the metallic grade is more hundred times than the nature mineral resources.
废弃电路板中蕴含的金属是天然矿藏品位的几十倍甚至几百倍，具有重要的回收价值。
2
This article mostly introduce reconstruction and recycle of close circuit variable pump.
主要介绍闭式变量柱塞泵的功能改造和再应用。
3
This article mostly introduces the reconstruction and recycle of close circuit variable pump.