斑岩铜矿( Porphyry copper deposits)为世界提供了50%以上的 铜金属( over 100 producing mines)。 Their close relatives the porphyry moly deposits produce 70%o of the world's moly. Both deposit types will be discussed separately, but they share many characteristics and are formed in somewhat similar manners
SUPPLY CHAIN VISIONS LOGISTICS TERMS and GLOSSARY Updated October 2003 ABB: See Activity Based Budgeting ABC: See Activity Based Costing ABC Classification: Classification of a group of items in decreasing order of annual dollar volume or other criteria. This array is then split into three classes called A, B, and C. The A group represents 10-20% by number of items and 50-70% by projected dollar volume. The next grouping, B, represents about 20% of the items and about 20% of the dollar volume. The