Barrick Gold Corporation (Williams Operating Corporation)

HEMLO CYANIDE DETOX PLANT & TAILINGS FLOTATION COMPLEX CONSTRUCTION – HEMLO, ON

Located alongside the TransCanada Highway No. 17 approximately 40 km east of Marathon, Ontario, the Williams Mine is comprised of an open pit mine, underground mine, ore processing and tailings facilities and it is owned by Williams Operating Corporation (also known as Barrick). Ore from the mine is co-mingled and fed to a standard grind, cyanide leach and carbon-in-pulp-extraction process. Williams Operating Corp decided to proceed with the Tailings Management Facility (TMF) Expansion Project at this site to enable future mine development and production beyond 2021. To expand the TMF, the following new and upgraded systems are required for construction:
  • Cyanide Detoxification System to reduce the level of reactive cyanide in the tailings corridor and in the Tailings Storage Facility (TSF);
  • Tailings Flotation Complex;
  • Conversion of the Old Boiler Room into the new Cyanide Detoxification and Tailings Flotation Electrical Room (named 3rd Floor Electrical Room);
  • Reagent Storage and Unloading Area to store and drop-off trailers of reagents to support the Cyanide Detoxification circuit; and
  • Final Tailings Pumping System upgrade to accommodate the proposed deposition plan for the future TSF.
In 2019, TESC was engaged by Williams Operating Corp to execute the above construction requirements, which included civil, structural, mechanical, piping, electrical and instrumentation, and scaffolding work. The TESC team was responsible for the following:                                                                                                                                                                                                                                                                                                                                      Cyanide Detoxification Plant
  • Relocation of diesel generator
  • Relocation of fence/berm
  • Yard area clearing
  • Location, excavation, and relocation of buried services
  • Rough and finish grading
  • Demolition of existing concrete pads
  • Steel Piles
  • Concrete building foundation
  • Concrete tank containment area
  • Embedded steel and anchor bolts
  • Equipment bases
  • Grouting
  • Erection of Pre-engineering building
  • Erection of Cyanide Detox Tank
  • Conversion of old boiler room into 3rd Floor Electrical Room
  • Steel supply, handling, and erection
  • Expansion of the existing Hydrated Lime system
  • Installation of the Sodium Metabisulfite reagent system
  • Installation of the Copper Sulfate reagent system
  • Refurbishment of existing CIP Tailings Pumps to new Paste Feed Pumps
  • Installation of other mechanical equipment, including pumps, tanks, standpipes, agitators, air receivers, air filters, chutes and enclosures, hoists, and trolleys
  • Installation of carbon steel piping systems, rubber lined piping systems, and stainless steel piping systems, including in-line instruments
  • Installation of HVAC equipment and ducting
  • Installation of electrical/instrumentation infrastructure and components, including cables and cable tray, grounding, instrumentation and control devices, atmospheric monitoring systems, CN WAD Analyzer System, owner supplied reagent system components, lighting transformers, lighting panels, push button stations, disconnect switches and receptables
Tailings Flotation Complex
  • Buried services locates
  • Demolition of existing concrete for foundation preparation
  • Local excavation for foundation work
  • Design, supply and install concrete formwork
  • Supply, install and place concrete and reinforcing steel for foundations
  • Supply, install and place concrete and reinforcing steel for equipment bases
  • Supply and install embedded steel and anchor bolts
  • Supply and install rock anchors/dowels
  • Supply and place grout
  • Structural steel supply, delivery, storage, and erection
  • Installation of the Potassium Amyl Xanthate (PAX) reagent system
  • Installation of the Frother reagent system
  • Installation of the Woodgrove Flotation system
  • Installation of other mechanical equipment, including tanks, pumps, standpipes, agitators, autosampler systems, air receivers, air filters, chutes and enclosures, safety showers, dust collection equipment, hoists, and trolleys
  • Installation of carbon steel piping systems, rubber lined piping systems and stainless steel piping systems, including in-line instruments
  • Installation of electrical/instrumentation infrastructure and components, including cables and cable tray, grounding, instrumentation and control devices, atmospheric monitoring systems, camera systems, PLCs, Delta Vs, lighting transformers, lighting panels, push button stations, disconnect switches, and receptacles
  • Installation of the new Mill generator (supplied by Barrick)
  • Connection of the new Mill generator to 3rd Floor Electrical Room
Old Boiler Room Converted to 3rd Floor Electrical Room
  • Removal of existing equipment and supplies
  • Modifications to existing concrete floor
  • Installation of concrete bases for equipment
  • Interior fire rated “shaftwall” construction wall system(s)
  • Penetrations through existing walls
  • Addition of new concrete masonry unit partition wall between electrical room and mechanical room
  • Dowels and embedded steel
  • Post-installed anchors
  • Modifications required to provide fire separation and room pressurization
  • Installation of HVAC equipment and ducting
  • Installation of electrical room equipment, including but not limited to MCC’s, VSDs, PLC Cabinets, Delta V Cabinets, Communication Cabinets, UPS and other additional electrical/instrumentation infrastructure and components
Final Tailings Pumping System
  • Installation of equipment bases
  • Piping demolition
  • Placement of final tailings pump (by Others)
  • Installation of piping
  • Installation of electrical/instrumentation infrastructure and components
  • Cast-in place anchors and post-installed anchors
Reagent Unloading Area
  • Yard area clearing (by Others)
  • Location, excavation, and relocation of buried services
  • Rough and finish grading
  • Installation of Lock-Block wall
  • Installation of concrete slab
  • Supply and installation of modified Sea-Containers for Reagent Storage Area
  • Handrailing
  • Bollards
TESC successfully executed construction while regular operations and production continued. To reduce the risk of critical operational interruptions, a detailed work plan was developed, which addressed operational limitations and requirements. The construction work plan included a traffic plan and environmental mitigation plan. TESC provided a milestone-based construction schedule which the team is diligently following to complete the project on time. A comprehensive site-specific safety plan was prepared and reviewed by all workers prior to construction.  As a result, the project concluded with no recordable injuries.

In-house Services Rendered

Civil

Structural

Electrical

Engineered Scaffolding

Millwrighting

Piping

Boilermaker