Abstract: The technology of by-layer by-grade mining is an effective way to achieve rational exploitation of bauxite in Shanxi Province. The technical connotation of this method is defined and its applicable scope determined. Based on a great deal of field tests, the rational technical parameters of by-layer and by-grade mining for Xiaoyi Aluminum Mine are set: 1) When there is no need of blasting operation, the width of mining strip is 5 m; valid depth of looseness 0.5~0.8 m; space between looseness 1.0~1.5 m; step height of mining 3.5~4.5 m; minimum width of work platform 26~28 m; and the front length generally 60~80 m. 2) In case of a need for blasting, the curve of the relationship between the width of blasting strip and the orebody dip angle (6°~18°) is given as well as the curve of the relationship between the front length and the orebody thickness. The front length will increase with the increase of dip angle, and decreases with the increase of thickness.

Key words: Opencast, Sedimentary bauxite, By-layer by-grade Mining, Working face parameters