The lower, the safer
Chapter 2: A risky survey
A risky survey
Risk increases when stopes must be surveyed. Stopes are the result of multilevel galleries union after successive explosions.
These rock-surrounded rooms are unstable, with loose sterile ore falling and walls collapsing. So risky, in fact, human access inside stopes is forbidden by safety engineers on site. Surveying control of these excavations requires high risk management.
Precise dimension and volume determinations are key to a successful gallery excavation plan and the general mine explorations plan.
Anglogold Ashantis, a leading global gold producer, operates four mines in the Brasilian state of Minas Gerais and Goiás. At almost 400 metres deep, the company’s Córrego do Sítio 1 Mine needs detailed information about its galleries and stopes for
- Volume calculations
- 3D models creation
- Mine reconciliation
Traditionally, stope surveys were performed with total stations. These surveys were done as quickly as possible since the surveyor is in a high-risk scenario inside the stope’s structure.
A few points were collected and the dimensions of the space interpolated and generalised. With the use of laser scanning, though, higher data quality became available to mine planners.