Tomingley Gold Project, NSW, Australia

The Tomingley gold project located in New South Wales (NSW), Australia is being developed by Alkane Resources as both open-pit and underground mine.

The project received the mining lease in February 2013 following which construction commenced. Mining operations commenced in January 2014 and the first gold bar was produced in February 2014.

In February 2023, the planning for the $30m extension of the Tomingley gold project was approved.

The project will double the life of the mine until 2031 and produce 745,000oz of gold.

Tomingley gold project location, geology

The gold mine is located to the south of Tomingley village and approximately 15km to the north of Peak Hill gold mine.

The open-cut mining operations include Wyoming Three, Caloma One and Caloma Two while the Wyoming One is operated as an underground mine.

The Tomingley deposit is located within the Eastern Belt (or the Macquarie Arc) of the early Palaeozoic Lachlan Orogen.

The Lachlan Orogen, categorised into Western, Central and Eastern Belts, comprises sedimentary, volcanic and intrusive rocks of early Cambrian to early Devonian age.

Reserves

The proven and probable reserves at Tomingley are estimated to be approximately 11.2 tonnes (t) grading 1.9g/t of gold, as of February 2024.

The total contained gold is estimated to be 664,000oz.

Mining method

The Tomingley gold project is mined using both open-pit and underground mining methods.

Conventional drill and blast followed by load and haul are used at the open-pit mines of the Tomingley gold project, whereas a longhole stoping method of mining is used at the Wyoming One underground mine, accessible via a portal.

The underground decline was developed using a drill and blast method while the load-haul-dump unit transported the fragmented material to the loading bay.

The mined-out stopes are backfilled using waste rock material sourced from the concurrent underground mine development.

Tomingley gold extension project details

The Tomingley gold extension project will extend gold mining operations to include the San Antonio and Roswell (SAR) resources to the south of the existing mine.

The project includes the development of an underground mine at Roswell and a large open-cut pit at San Antonio.

The proposed SAR open cut will combine the San Antonio and Roswell deposits, with up to three subpits.

The underground section at the Roswell deposit commenced in April 2024 and utilises an exploration drive that extends from Wyoming One.

Ore processing at Tomingley gold mine

The extracted ore is transported to the run-of-mine (ROM) pad via haul trucks and is blended by the front-end loader and delivered to the ROM coarse ore feed bin.

It is then taken to the primary jaw crusher with a throughput capacity of 170t per hour. The underground loader fleet is planned to be upgraded to the latest CAT 2900XE diesel-electric loaders by 2024.

The crushed ore passes through a series of conveyors before screening. The oversized material is sent to a secondary crusher for further crushing while the undersized material is taken to the surge bin.

The ore is treated in the carbon-in-leach circuit followed by carbon leaching and electro-winning process.

Gold dore bars are produced on site and stored before being transferred to a gold refinery. Tailings are stored in the Residue storage facility located south of the processing plant.

Infrastructure facilities at the Tomingley mine

Major works included the construction of three waste rock emplacements, a haulage road underpass beneath the Newell Highway, a ROM pad, a processing plant, a crushing and grinding circuit, a carbon-in-leach processing plant, site offices, and associated infrastructure.

The mine is accessed via a road connecting the site to the Tomingley West Road.

A new bypass section for the highway is being constructed as the SAR deposits are located underneath the Newell Highway.

The existing Kyalite Road will also be realigned as it runs through the proposed SAR open cut.

Water is supplied by the 46km-long water supply pipeline from Woodlands property situated 7km east of Narromine.

Financing for the Tomingley gold project

The gold mine was financed through a $107m loan facility taken for developing the Tomingley and Dubbo Zirconia projects.

Contractors involved

Mintrex was awarded the engineering, procurement, construction and maintenance contract for the project.

Mintrex awarded Interquip the structural, mechanical, and piping construction contract for the Tomingley gold processing plant.

RW Corkery was engaged to conduct an environmental assessment study for the gold mine.