Abstract: Open pit limit optimization is an important link in open pit design, production and operational management and is a complicated work involving an integrated consideration of mine resource conditions, mining technical condition, mineral sales price, ore mining and processing cost for maximizing the economic benefit.The study on the open pit limit optimization of Yimen copper mine in Yunnan Province is made by means of Lerchs-Grossmann optimization method and 3D visualization technology.Through the study of the parameters and method for open pit limit optimization, an economically optimized open pit limit is obtained, hereby providing a basis for direct technical scheme and investment policy decision for the mine exploitation.The main techniques and method applied in open pit limit optimization are summarized.

Key words: Open pit mine, Pit limit optimization, MicroMine software, Planning and design, L-G metho