PFC numerical analysis on prediction of ore loss and dilution of ore drawing below backfilling waste rock layer

摘要

When open-pit mining transferred to underground mining, the backfilling waste rock layer has a certain impact on ore loss and dilution of ore drawing. There are three main factors of ore loss and dilution below backfilling waste rock layerbackfilling waste rock layer thickness, waste rock particle diameter and non-uniformity. Based on the experimental data of different tests, the ore loss and dilution rate of the mathematical model below the backfilling waste rock layer was established. Combined with the HI stope from open-pit mining to Underground in the Sijiaying Steel mine, the backfilling waste rock non-uniformity and particle diameter were designed. According to ore loss and dilution effect factors in the drawing the orthogonal experiments are designed, adopting particle flow numerical simulation methods, the relationship are set up on dilution ratio, backfilling waste rock layer thickness, particle diameter, particle diameter non-uniformity and loss rate through absolute factors and relative factors separately. It will be helpful for the backfill layer design in similar conditions.