Study On The Grade Indexes System Of Mineral Resources Reserves Under The New Reserves Classification Standard

China in June 1999 issued《Resources/Reserves Classification Standard》, in December the same year it started to implement. According to the economic significance, the new classification scheme was divided into four major categories, namely, the economic, the marginal economic, sub-marginal economic, intrinsic economic, in which the economic sense was determined there are three types. So there must be three lines to divide the different reserves/resource types. From above all, we can see that The old grade indicator has been unable to meet the requirement the circumstances of《Resources/Reserves Classification Standard》, nor adapt to the market economy. This is objectively seek to amend the old grade indicators in order to meet the《Resources/Reserves Classification Standard》and the market economy. According to the requirement of《Resources/Reserves Classification Standard》, there must be four-grade indicators to be the delineation of ore bodies. The author has put forward the concepts of four kinds of grades and the methods to determine them. They are respectively named cut-off grade, marginal grade, economic grade and the average grade.1) In this paper, the research significance, methods and features of the grade indexes under the classification criteria of mineral resources reserves were described and related factors of the reserves classification quality indicators were analyzed.2)According to the requirement of《Resources/Reserves Classification Standard》, there must be four-grade indicators to be the delineation of ore bodies. The author has put forward the concepts of cut-off grade, marginal grade, economic grade and the average grade. The grade between cut-off grade and marginal grade, it will be sub-marginal economic resource; the grade between marginal grade and economic grade, it will be marginal economic reserve; the grade between economic grade and the average grade, it will be economic reserve. The value of investment for an ore deposit can be judged with the last one.3) Method & Procedure of each grade index was introduced respectively. For cut-off grade, based on lane model and facts of the mine, the lane model formula was re-deduced and obtained with the largest NPV objective optimization mathematical model of the grade; For marginal grade, used optimization methods to maximize the net-present-value, and made reference to price fluctuations of market economy, as well as, made dynamic adjustment to the marginal grade; For economic grade, adopted calculation method of the economic grade under the breakeven, and made a dynamic assessment of the indicators; For the average grade, based on the actual data of mine, used numerical averaging method and the weighted average method to calculate the average grade.4) With Microsoft Visual Studio 2005.NET as a platform designed for dynamic management of information systems quality indicators. Specific conditions in combination with minerals, analysis of their mining technical and economic indicators, calculated each grade indicators for mining enterprise management decision-making. Combined with a gold mine production data for analysis and a classification of indicators to identify and reserve classification.