Sagittarius Mines, Inc. was developing the Tampakan Copper-Gold Project, an open pit mine and processing facilities, located approximately 50 km north of General Santos City on the Philippine island of Mindanao. If developed, the mine would be the largest in the Philippines and among the largest copper mines in the world. The proposed mine site covers an area of approximately 10,000 hectares.
If approved, the mine was estimated to yield an average of 375,000 t/y of copper and 360,000 ounces per annum of gold in concentrate over the 17 year period of mining and ore production.
Ausenco’s involvement began with a bankable feasibility study of slurry transport for the copper concentrate and tailings systems, and continued to include a study of two new route alternatives and an update of the feasibility study.
Bankable feasibility study
Xstrata, manager of the Tampakan project, initially contracted us to provide a bankable feasibility study which included hydraulic design of the transport systems along with a cost estimate to ±15%.
Our design scope included the pump station, slurry pipeline and terminal station (choke station) for concentrate pumping; and the pump station, slurry pipeline, tailings header pipe, and deposition mechanism and arrangement for the tailings transport system. Support facilities for both systems were also included.
In this phase, the concentrate system was designed to transport up to 1.5 million dry tonnes per year (Mt/y) from the concentrator to the port facility at General Santos, and included an 80.8 km, HDPE-lined steel pipeline with a 12/10-inch diameter, fusion-bonded epoxy exterior coating and impressed current system.
The concentrate pipeline route began at an elevation of 930 metres above sea level (masl), reached a high point of 1,244 masl, descended to a low point of 35.5 masl, and finally ended at 54 masl.
In addition to the pipeline, the concentrate transport system also included a pump station with two positive displacement pumps (one operating and one standby), a valve station, a terminal station, two pressure monitoring stations and ancillaries.
The dual 9.84 km, 30-inch tailings pipelines were designed to transport up to 65.0 Mt/y. The tailings system began at an elevation of 861 masl, reached a high point of 878 masl and low point of 838 masl, and ended at 856 masl.
The tailings system also included one sump, one pump station, nine gland seal water pumps, two choke stations (one each) and six fixed chokes (per pipeline) located at the tailings dam distribution header.
This study was completed in early 2010.
Alternative route study
Later that same year, we evaluated two new route options for the concentrate pipeline which ended at the port at Malalag.
The first route option (via Bonafacio) spanned 64 km and was located and ran cross-country for all but 7 km.
The second route option (via Malandag) was slightly longer at 77 km, and ran cross country for 11 km, continued in the right of way of a secondary road for 30 km and finally ran in the right of way of the national highway for approximately 36 km.
The alternative route study was completed in 2010.
Feasibility study update
Following completion of the route study, in 2011 we completed an update of the feasibility study for Xstrata through agent Bechtel to reflect the new pipeline route to Malalag.
The revised design included a 52 km, 10/8-inch, HDPE-lined steel pipeline for the transport of 1.7 Mt/y with one pump station, a terminal choke station, one pressure monitoring station at the high point and cathodic protection.
The pipeline began at 861 masl, reached a highpoint of 1,115 masl and ended at 20 masl.
Our scope in this phase included hydraulic design of the new pipeline and CAPEX/OPEX to ±15%.
Our study was completed in early 2011.
- Laboratory testing
- Hydraulic design
- Bankable feasibility study
- Alternative route study
- Feasibility study update
- High-level cost estimates.