4.2　Industrial Index of Mineral Deposit

4.2.1　The industrial index of mineral deposit shall be determined based on compliance with mineral deposit geological features so as to maintain continuity and integrity of orebody and meet the requirements of resource comprehensive utilization and market demands.The optimum scheme shall be determined on the premise of feasible mining technology and reasonable economical efficiency.Methods used for determination of industrial index of mineral deposit shall include analog method，geological scheme method and economic analysis method，etc.

4.2.2　Industrial index of mineral deposit shall have such basic contents as cutoff grade，minimum industrial grade，minimum exploitable thickness and horsestone removal thickness.

4.2.3　When orebody limits are delineated，cutoff grade shall be used for single sample，the minimum industrial grade shall be used for continuous sample section of individual mineral exploitation engineering or for small block section，and minimum exploitable thickness and horsestone removal thickness shall be the true thickness of rock of the project.

4.2.4　For preparation of industrial index in Geological Investigation Report，the construction party shall submit Mandate of industrial index of mineral deposit，and geological investigation party shall submit recommendation of industrial index to the department of Land and Resources for review and records.In case the ore property is complicated，the engineering company shall provide technical and economic verification and submit industrial index scheme to the department of Land and Resources for review and records.