The room-pillar mining method is currently used in Aojiawan bauxite mine,with a large number of pillars supporting the roof,low recovery rate and large ore loss.In order to recover bauxite pillar safely,the stress distribution of pillar and backfill before and after filling was analyzed theoretical-ly.A technology of roadway-by-roadway backfilling mining to recover pillar for bauxite utilizing high water material was proposed and field tests were carried out,according to the occurrence characteristics and mining conditions of the bauxite body.Each bauxite pillar was divided into several mining roadways.The high water filling material with the water-cement ratio of 4∶1 was used to cement the gangue,and the pillar was recovered by orderly fill-ing roadway-by-roadway.In order to evaluate the mechanical properties of the backfill,field sampling and laboratory test were carried out.The results show that the uniaxial compressive strength of the backfill is 2.84 MPa,the backfill can effectively support the roof.At the same time,the backfill can weaken the stress concentration of pillar and improve the overall stability of stope.The technology can recover the pillar safely,increase the ore recovery rate to 81％.Meanwhile,it can effectively control the overlying strata movement after bauxite mining,and the filling cost is low with remarkable technical and economic benefits.
关键词
铝土矿/高水充填材料/逐巷充填开采/矿柱回收/采出率
Key words
bauxite/high water filling material/roadway-by-roadway backfilling mining/pillar recovery/recovery ratio
维普
万方数据