BRIEF INTRODUCTION OF WORKING PRINCIPLE OF USA'S MINERAL AVAILABILITY SYSTEM

Goal of research of mineral availability is to analyse quantitatively the supply ability of important mineral deposits in the world and provide reports about minerals availability under price changing conditions of today and future market.To ensure the economic development and state safety,know well the status of home and abroad supply of minerals and their products and stabilize its own minerals market,the USA government has invested 1 billion US in 1970's-1980's to help Bureau of Mines establish a Mineral Availability System for market economy counties.