La Quintana Gold Mine - Columbia La Quintana Gold Mine - Columbia La Quintana Gold Mine - Columbia La Quintana Gold Mine - Columbia

La Quintana Gold Mine - Columbia

La Quintana is a small 65tpd underground gold mine in northern Colombia. The dipping gold bearing quartz veins occur in a competent granodiorite host rock, and are worked from stopes off levels from a single incline. We were commissioned to carry out a geotechnical assessment of the backfill requirements to enable pillar extraction of mined stopes to increase recovery to nearly 90% - in a remote area with few supporting facilities and only limited background information on the geotechnical rock mass parameters.

We devised a simple programme of cement backfill testwork, implemented in country to provide results for finite element analysis. Using available information and the results of underground geotechnical assessments we produced a geotechnical model of the underground situation. We then used FLAC software to assess the geotechnical stability of the backfill pillars, identified a way forward to develop the design, and advised on the optimum mix of cement, tailings, fines and water to produce backfill with the required strength.

The mine implemented backfilling to our specified mix. Initial test results indicated that the required strength was obtained, and the remnant pillars were successfully extracted as planned.