Australia

Northern Operations (Cooljarloo) Complex

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Categories

Overview

Mine TypeOpen Pit
StatusActive
Commodities
  • Titanium
  • Zircon
  • Rutile
  • Ilmenite
  • Synthetic rutile
Mining Method
  • Truck & Shovel / Loader
  • Dredging
  • Dry mining
Production Start1989
Mine Life2038
SnapshotThe Northern Operations (Cooljarloo) include:
• Cooljarloo Mine where heavy mineral concentrates are produced from dredge mining operations.
• Cooljarloo West and Osprey deposits, which conjoin the Cooljarloo Mine operations;
• Chandala Processing Plant where the heavy mineral concentrates (HMC) are separated into saleable mineral products and also where ilmenite is further upgraded to synthetic rutile.

The Cooljarloo West dredging orebody expected in approximately 2033.
Related Asset

Owners

SourceSource
CompanyInterestOwnership
Tronox Holdings Plc. 100 % Indirect
Tronox Management Pty Ltd (operator) 100 % Direct
Tronox Management Pty Ltd is a subsidiary of Tronox Holdings plc and is the operator of Tronox Northern Operations.

Contractors

ContractorContractDescriptionRef. DateExpirySource
Piacentini & Son Pty Ltd. Mining Piacentini & Son have been at Cooljarloo since January 2007, and the Company has recently been awarded the Mining and Earthmoving Contract by Tronox for a further 5 years. Nov 1, 2019 5
unawarded or unknown Logistics and Material Handling Dec 31, 2023
Weir Group PLC Mine Operator 12 January 2021 - Weir Minerals have further strengthened their partnership with Tronox by entering into an exclusive arrangement to take ownership of the maintenance, asset management and optimisation of the mine’s key assets. With a Total Asset Management Plan, customers have a dedicated Weir Minerals team who take responsibility for their assets – providing real-time innovation and improvements, backed by in-depth knowledge and experience. Jan 12, 2021

Deposit type

  • Sedimentary
  • Mineral sands

Summary:

The mineral sand deposits occur at the top of a series of sedimentary deposits, within a sequence of relatively recent unconsolidated sands.

They generally originate from the adjacent Yilgarn Block, which has been eroded, transported by rivers and streams and deposited as beach sands along former coastlines.

The deposits now form successive north-south linear deposits well inland from the present coast. Upper level deposits that either outcrop or are covered by minimal amounts of nonmineralised material (overburden), occur in the northern half of the tenement. Mid-level deposits are covered with varying depths of overburden. The basement deposits occur below the mid-level deposits and are typically more weathered and of lower heavy mineral grade.

Tronoxs Resources are marine shoreline strands and the location and style of mineralisation is affected by the sedimentary processes which gave nse to them. The base and western (shoreward) margins tend lo be discrete as these are a wave cut platform or similar coastal notch They tend to be elongate shapes with lengths of up to 12km and lateral width of 100-300m and thicknesses of up to 10 metres. The strands tend to be gently curved and can be interrupted by later erosion by cross-cutting surface water systems.

Reserves at December 31, 2023

The cutoff grade used for the resource estimate is based on a nominal bottom cut of 1.0% HM.
CategoryTonnage CommodityGradeContained Metal
Proven & Probable 307 Mt Heavy Minerals 1.8 % 5.5 Mt
Proven & Probable 5.5 Mt Zircon 11.6 %
Proven & Probable 5.5 Mt Ilmenite 61.2 %
Proven & Probable 5.5 Mt HiTi (rutile-leucoxene) 8 %
Total Resource 295 Mt Heavy Minerals 1.6 % 4.7 Mt
Total Resource 4.7 Mt Zircon 10.4 %
Total Resource 4.7 Mt Ilmenite 61.2 %
Total Resource 4.7 Mt HiTi (rutile-leucoxene) 6.8 %

Mining Methods

  • Truck & Shovel / Loader
  • Dredging
  • Dry mining

Summary:

Cooljarloo produces heavy mineral concentrates from dredging and dry mining operations.

The dredging operation uses one of the world’s largest floating dredges in a purpose-built pond to pump slurried ore at a rate of 3,000 tonnes per hour to a floating concentrator which recovers heavy minerals from the sand and clay using a series of gravity spirals. The heavy mineral concentrate produced at Cooljarloo is transported south in specially designed road trains to Tronox’s Chandala Processing Plant for separation and processing.

As mining operations move through the orebody, sand and clay are returned to fill the void and the surface is contoured to landforms similar to those that existed prior to mining. Because less than 5% of the total sands mined are removed during mining, the rehabilitation program can establish similar landforms and ecosystems to the original countryside.

Overburden is generally removed 3 months ahead, exposing enough ore to keep apart the dredges and mining face so as not to compromise safety and production risks. Overburden is usually dumped directly onto the sand tailings beach at the back of the pond, or onto dried out clay-fines cells, to create final landform. Truck types commonly used are Cat 785B and 777's as well as articulated D400E. Excavator used is typically a Komatsu PC2000.

Over the life of mine, overburden quantity averages 5Mbcm/a. Any high overburden faces are extracted in 4 metre benches. Pit wall slopes are typically 30 degrees but can be up to 45 degrees in areas of higher clay content.

Two dredges operate in a pond up to 25 m deep and mine ore between 22 and 30 m thick. Together they mine 24 million tonnes of ore per year, which is delivered to the shared Wet Processing Plant. The pond water is natural groundwater and is fresh. The pond is up to one k long and 400 m wide. These facilities are controlled by operators via computers and GPS satellite navigation.

HMC is pumped to a central stockpile where it is stacked, ready for rehandling into road trains for transport to our processing facility at Chandala. Tailings from the plant comprise washed sand and clay at 2,950 tonnes per hour. The tails are directed either via a float line and floating tails stacker back to the dredge pond to form stable beaches and return stripped overburden or sent via external tails pipelines up to six kilometres in length to backfill previously mined out pits.

Clay from the ore is dried in purpose-built cells on the mined pits and on future mine path. No chemicals are used in the process.

Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

  • Acid leach
  • Electrostatic separation
  • Spiral concentrator / separator
  • Desliming
  • Centrifugal Jig
  • Dry Screening
  • Wet Screening
  • Gravity separation
  • Magnetic separation
  • Dewatering
  • Rotary kiln & Electric furnace

Summary:

Northern Operations complex in Western Australia is consisted of the Cooljarloo dredge mine and floating heavy mineral concentration plant and the Chandala metallurgical site which includes a mineral separation plant and a synthetic rutile plant that produces synthetic rutile.

Two dredges in a single pond feed an ore slurry to a floating concentrator to produce HMC, which is hauled by trucks 110 km south to our Chandala metallurgical complex near Muchea, 60 km north of Perth, for the recovery of ilmenite, rutile, leucoxene and zircon. Ilmenite is upgraded at Chandala to SR, a high-TiO2 feedstock for our Kwinana and other TiO2 pigment plants.

Processing - Both wet and dry mining techniques utilize wet concentrator plants to produce a high grade of heavy mineral concentrate (typically approximately 90% to 98% heavy mineral content). Screened ore is first deslimed, a process by which slimes are separated from larger particles of minerals, and then washed through a series of spiral separators that use gravity to separate the heavy mineral sands from lighter materials, such as quartz. Residue from the concentration process is pumped back into either the open pits or slimes dams for rehabilitation and water recovery. Water used in the process is recycled into a clean water dam with any additional water requirements made up from pit dewatering or rainfall.

Spiral wet gravity concentrators are used for the recovery of VHM at Cooljarloo. The spiral circuit consists of five stages: roughers, middlings, cleaners, recleaners and classifiers. Clay fines are managed by entrapment in sand tailings and natural thickening and removal in the pond. No flocculants are required in the process. The plant spiral circuit layout is set up as two parallel streams as this facilitates steady operation should one dredge be shut down and also facilitates access for unscheduled maintenance events.

Mineral Separation - The non-magnetic (zircon and rutile) and magnetic (ilmenite) concentrates are passed through a dry separation process, known as the “dry mill” to separate out the minerals. Electrostatic and dry magnetic methods are used to further separate the ilmenite, rutile and zircon. Electrostatic separation relies on the difference in surface conductivity of the materials to be separated. Conductive minerals (such as ilmenite, rutile and leucoxene) behave differently from non-conductive minerals (such as zircon) when subjected to electrical forces. Magnetic separation techniques are dependent on the iron content of a mineral. Magnetic minerals (such as ilmenite) will separate from non-magnetic minerals (such as rutile and leucoxene) when subjected to a magnetic field. A combination of gravity and magnetic separation is used to separate zircon from the non-magnetic portion of the heavy mineral concentrate.

Synthetic rutile plant
Synthetic rutile is made by reducing ilmenite in a rotary kiln, followed by leaching under various conditions (acid leaching) to remove the iron from the reduced ilmenite grains. Our synthetic rutile has a titanium dioxide content of approximately 89% to 92% and is also considered a TiO feedstock material.

Water Supply

Summary:

There is a large freshwater aquifer (Yarragadee) immediately to the west of the Brand highway adjacent to the Chandala site. Tronox has a borefield there to supply the licensed 1megalitre/annum of water that the site requires. Even in times of severe drought, supply from this aquifer has never been at risk. Cooljarloo draws from an extensive field of relatively shallow bores and also an extension of the Yarragadee aquifer. To limit pumping distances, it has been preferable to have multiple smaller bores around the site since the dredging operation has travelled more than 40km within the mining lease area since 1989. The dredging operation uses approximately 1.5GI of water per month of which 0.5GI comes from a shallow bore field network across the site The rest comes from natural ground water inftow to the dredge pond and returns from off path clay fines thickening cells.

Production

The production of Rutile includes natural rutile and leucoxene.

The production of Ilmenite includes multiple grades of TiO2, grades of Ilmenite.

The owner did not publish production data for 2019 and 2020.
CommodityProductUnits202320222021201820172016
Heavy Minerals Concentrate kt 232266317
Zircon Mineral in concentrate kt 192227343441
Rutile Mineral in concentrate kt 151926242832
Ilmenite Mineral in concentrate t 126,675143,049185,481

Operational metrics

Metrics20232022202120202019201820172016
Hourly processing capacity 2,850 t
Annual production capacity 36,000 t of rutile mineral in concentrate36,000 t of rutile mineral in concentrate35,000 t of rutile mineral in concentrate35,000 t of rutile mineral in concentrate35,000 t of rutile mineral in concentrate35,000 t of rutile mineral in concentrate35,000 t of rutile mineral in concentrate
Annual production capacity 70,000 t of zircon mineral in concentrate70,000 t of zircon mineral in concentrate40,000 t of zircon mineral in concentrate40,000 t of zircon mineral in concentrate40,000 t of zircon mineral in concentrate40,000 t of zircon mineral in concentrate40,000 t of zircon mineral in concentrate
Annual production capacity 26,000 t of leucoxene mineral in concentrate26,000 t of leucoxene mineral in concentrate
Annual production capacity 220,000 t of synthetic rutile240,000 t of synthetic rutile240,000 t of synthetic rutile230,000 t of synthetic rutile220,000 t of synthetic rutile220,000 t of synthetic rutile220,000 t of synthetic rutile220,000 t of synthetic rutile
Waste
Tonnes processed 23,558 kt25,104 kt23,808 kt
Hourly mining rate 3,000 t of ore
Annual mining capacity 24 Mt of ore

Production Costs

Commodity production costs have not been reported.

Financials

Units2023
Book Value M USD 428  

Heavy Mobile Equipment

Ref. Date: December 31, 2023

SourceSource
HME TypeModelSizeQuantityLeased or
Contractor
Dredge 2
Excavator Komatsu PC2000 250 t Leased
Truck (dump) Caterpillar 785B Leased
Truck (dump) Caterpillar 777 100 t Leased
Truck (dump) Caterpillar D400E Leased

Personnel

Mine Management

Job TitleNamePhoneEmailProfileRef. Date
Director - HSE James Owen 0439 912 908 james.owen@tronox.com LinkedIn Mar 17, 2024
Mining Manager Mathew Helms LinkedIn Mar 17, 2024
Production Manager Mathew Brandt LinkedIn Mar 17, 2024
Technology Manager Braam Rousseau LinkedIn Mar 17, 2024

Total WorkforceYear
275 2023
275 2022
144 2019

Aerial view:

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