The Los Bronces copper ore pipeline system conveys a milled and thickened product from Los Bronces Mine to a flotation plant in Las Tortolas.
The system currently includes a 52km, 28-inch diameter, 37.5 million tonne per year (mt/y) ore pipeline and a 52km, 24-inch diameter water pipeline.
Compañia Minera Disputada, now Anglo American Sur, selected Ausenco to perform a full range of services throughout the pipeline system development, from studies through to design work, beginning in 1998.
Original pipeline expansion
In 1988, the Los Bronces system expanded operations to process up to 11.4 mt/y (33,000 tonnes per day) of copper ore. This expansion necessitated the relocation of the concentrator. Ausenco was selected as a specialty sub-contractor to perform the following services during the project:
- Scoping study (which resulted in elimination of a 5km tunnel)
- Pipeline and choke station sizing
- Basic hydraulic design
- Review services during basic and detailed engineering phases
- Start-up operations assistance
Following this work, Ausenco was selected to provide an expert consultation to Exxon Production Research for a wear audit. The investigation focused on a high wear condition noted at the beginning of the pipeline and the erosion monitoring system.
Our scope included:
- Review of slurry pipeline erosion measurement techniques (location and methodology)
- Analysis of the anomalous wear rates at the upper end of the pipeline (initial section)
- Analysis of damage to the polyurethane liner in the choke stations
- Analysis of the suitability of current measurement techniques and recommendations for modifications
- Forecast of remaining pipeline life
In 2002, Ausenco was retained with joint venture partner JRI to complete basic and detailed engineering for the replacement of the original 20-inch buried copper ore pipeline, which had exceeded its design life. The pipeline was incrementally replaced with a new 24-inch diameter pipe, increasing throughput to 18.7 mt/y (54,000 tpd).
Our scope of work in this phase of the project included:
- Full basic and detailed engineering of the pipeline replacement (all disciplines)
- Hydraulic design of the new transport system, including transient analysis
- Route selection to permit installation in parallel to the existing 20-inch diameter concentrate pipeline and a 14-inch diameter tailings pipeline
- Construction and tie-in plan to minimise risk to existing facilities and minimise down-time for change-over
- Cost estimates
- Procurement services
Ausenco also performed an inspection of several choke station spool failures, as there was some concern about the viability of the existing choke stations with the higher flows of the new pipeline.
The audit included recommendations to improve lining techniques and quality control, as well as process changes.
In 2005, Ausenco performed a conceptual study to evaluate the new system with the replacement pipeline.
Our scope of work included:
- Analysis of the effects on the system of upgrading to 24-inch pipe and increasing solids concentration
- Review of the current 150 foot and 300 foot thickeners for their ability to produce higher concentrations and associated operating curves and hydraulics
- Analysis of thickening beyond what the existing thickeners could achieve (up to a maximum solids concentration of 75%), and evaluation of the feasibility and implications of a resulting increase in solids throughput
In 2008, the system was expanded again to allow processing of 37.5 mt/y. Ausenco offered design and support services for the expansion, including:
- Conceptual design
- Basic and detailed engineering for a new 52km, 28-inch copper ore pipeline with five high-pressure choke stations
- Detailed engineering for a water recovery system including five pump stations
- Field engineering support
Our control systems group was also contracted to provide Ausenco’s Pipeline Advisor™ leak detection and process optimisation system as well.
This phase was completed in late 2011.