Location: Mesa J near Pannawonica, WA
Client: Rio Tinto
Duration: February 2020 – September 2020
Mobilised, set-up site, constructed Embankment 9 (approximately 88,300 m3) and established the pipeline access road and installed 1.3 km of HDPE-lined steel and HDPE pipeline in one and a half months during the COVID-19 pandemic, to achieve the temporary deposition milestone. Continued to construct the remainder of the tailings storage facility whilst tailings were being deposited into TSF3. Mining Operations achieved a short haul stockpiling and replenishing mine waste we used in construction.
- Foundation preparation;
- Dump rockfill to create a stable foundation;
- Excavate cut-off trench;
- Line the cut-off trench with geosynthetic clay liner (GCL);
- Construct embankments and decant causeway ramps out of conditioned mine waste;
- Place and compact in 1m lifts;
- Excavate drains;
- Trim subgrade and batters;
- Construct windrows;
- Install guideposts and delineators;
- Road pavement construction;
- Trim wearing course material;
- Construct temporary pit protection bund;
- Supply and install VWP’s and data loggers;
- Drill and grout to install VWP’s through embankments;
- Extend existing VWP’s to new data loggers;
- Procure manual handwheel knifegate, ball, butterfly, air valves, OD400 (DN400) SDR11 PN16 PE100 HDPE pipe, OD355 (DN350) SDR11 PN16 PE100 HDPE pipe ,OD225 (DN200) SDR17 PN10 PE100 HDPE pipe, OD200 (DN200) SDR11 PN16 PE100 HDPE pipe, Table F and Table E backing rings, reducers, tees, sweep bends and elbows, gaskets, bolt sets, mining hose, decant manifolds, solar-powered telemetry skids and pressure transmitter;
- Establish pipeline access roads;
- Relocate existing DN350 HDPE-lined steel pipe flanged Table H, DN400 HDPE-lined steel pipe flanged ANSI150, mining hose, 18no. pneumatic-actuated spigot valve assemblies on skids reconfigured to suit, from across Mesa J mine at TSF4 and TSF5, and install at TSF3;
- Reseal knifegate valves on spigot valve assemblies, both high pressure and low pressure;
- Construct pipe crossings for HV and LV’s;
- Polyweld and install kilometres of tailings pipeline at TSF3 and TSF5;
- Polyweld and install kilometres of decant return water pipelines;
- Hydrostatic pressure test;
- Install 79no. valves;
- Install pressure transmitters;
- Install 2no. solar-powered telemetry skids;
- Energise and commission;
- Install flood level indicators.
