To serve you better, our new website displays information specific to your location.
Please visit the site and bookmark it for future use.
Closure Planning on a Large Scale – Approach to Optimising PFS Closure Designs for the Western and Central Development Areas at a site in Central Laos
Author(s):
John Chapman, Claire Linklater, Daryl Hockley, Justin Rowntree, Donna Noonan
Date:
Tuesday, September 4, 2018
First presented:
Mine Closure 2018
Type:
Article
Category:
Mining
Closure plans for an extensive mine site located in central Laos are currently being developed. The mining area includes more than 40 pits, some of which have been backfilled, and 13 waste rock dumps.
In support of the development of the closure strategy, technical studies have been completed which included development of a site-wide water and load balance, assessment of the geotechnical stability of pit walls and dumps, and geochemical characterisation to understand the distribution of ongoing sources of solute production around the site. Specific issues associated with the site include proximity of local communities and accessibility of the site, stability of the pit high walls and exposure of acid forming rock on the high walls, positive water balances for the pit lakes and the large distance across which the site is spread.
Future water quality predictions were combined with the site-wide water balance to develop an integrated closure strategy for the site, identifying optimal closure measures to mitigate water quality impacts to downstream receptors (drinking water resources) and ensure public safety. Conceptual closure designs for WRDs and pits were developed incorporating both passive and active water management infrastructure. Two companion papers describe the development of the water balance and the water quality predictions. This paper presents the practical implications of the outcomes and the overall closure strategy that was developed for the site.
