Tag Archives: Sugar Zone

Harte Gold goes with the Watson-Marlow flow at Sugar Zone

Harte Gold’s wholly-owned Sugar Zone Mine in Ontario, Canada, is now benefiting from the adoption of Qdos and APEX peristaltic pumps from Watson-Marlow Fluid Technology Group (WMFTG).

Having deployed the pumps in two important applications, the Sugar Zone team are now enjoying far better flow rate efficiency, along with significant reductions in both maintenance requirements and downtime, according to WMFTG, with the miner subsequently looking to invest further in the company’s pumping technology.

The Sugar Zone Mine entered commercial production in 2019 and has an anticipated operating life of around 13 years at current output levels. Producing 60,000-65,000 oz/y of gold at a 800 t/d throughput rate, a mine expansion study is currently in progress to support a 1,200 t/d rate.

In the reagents room, Harte Gold operates eight diaphragm pumps on a 24/7 basis. However, issues over insufficient process efficiency, the amount of maintenance time needed to replace diaphragms and the potential for leaks prompted the company to look at alternative solutions.

Harte Gold invited WMFTG to trial its Qdos 30 chemical metering pump. For a period of one month, the mining company compared the Qdos with an existing electric diaphragm pump dosing flotation reagents such as potassium amyl xanthate (PAX).

With a flow rate for PAX of 100-300 ml/min, the Qdos 30 significantly outperformed the diaphragm pump on flow rate efficiency, according to WMFTG. Although the dosage rates were adjusted as required before and during the trial, the Qdos outputs were noticeably more consistent in comparison with the existing pump, bringing potential for process optimisation.

ReNu peristaltic pump head technology is at the core of the Qdos pump and is key to its success at Harte Gold, WMFTG says. ReNu ensures accurate and repeatable chemical dosing and, thanks to its contained design with integral leak detection, reduces wastage and eliminates any potential for operator exposure to chemicals.

In addition, Harte Gold personnel confirmed both operations and maintenance were trouble-free during the trial runs. Indeed, there were favourable reports of the colour TFT display, which shows both flow and speed, while the maintenance team was in full support of the single, no tools ReNu pump head replacement.

Such was the success of the trial that Harte Gold is now looking to gradually phase-out all eight of its existing diaphragm pumps in the reagents room over the coming few months. Although control of the first Qdos 30 on site is manual, the company will adopt 4-20 mA I/O moving forward, according to WMFTG. Harte Gold is also planning to replace diaphragm pumps with Qdos models on the water treatment side of its business.

In another area of its operations, Harte Gold has replaced an existing peristaltic pump (not Watson-Marlow) with an APEX 35 in a 24/7 application. Here, the pump transfers thickened gravity concentrate from a gold decanting tank to a shaker table. However, the company found itself replacing hoses every week in its existing peristaltic pump.

The company already had an APEX 35 in operation so thought the same model would provide a good solution for the thickened gravity concentrate. Instead of the one week hose life previously achieved, the APEX 35 with NR hose lasted for 12 weeks, reducing both maintenance and downtime in this critical application. Now, only four hoses are required per year, rather than 52, equating to a 1,200%-plus gain in maintenance intervals, the company said.

Harte Gold to go commercial at Sugar Zone mine in Ontario

Harte Gold has been given the go ahead by the government of Ontario to start commercial production at its Sugar Zone mine, paving the way for full-scale output of 1,400 t/d in 2021.

This approval means the company is fully permitted to mine, process ore and pour gold on site at Sugar Zone.

Even though Harte has only just received provincial signoff for Sugar Zone’s commercial plan, it has been busy on site where it has already completed a 70,000 t advanced bulk sample, mined 30,000 t of ore under a Phase 1 Commercial Production permit and built an 800 t/d processing plant.

With this permit ticked off, the company can now proceed with its commercial production plan. This envisages a start-up of operations at 540 t/d at Sugar Zone, increasing to 800 t/d in the December quarter of 2019 and, subsequently, to 1,400 t/d from January 2021.

A preliminary economic assessment envisaged the total upfront capital cost at C$58 million ($45 million) and production, from 2019, of 80,700 oz/y at an all-in sustaining cost of $708/oz over an 11-year mine life.

This would see 904,000 oz of total recovered gold production over the mine life, approximately two thirds of the combined indicated and inferred resources announced back in February, Harte noted in the PEA.

In the latest press release, Harte Gold said full commissioning of the mill complex was nearing completion, while testing of the crushing and conveyance system was complete. Water had been successfully circulated through the mill and the power line to site was built, with all electrical equipment delivered and installed.

Underground development work, meanwhile, continues to exceed targeted rates, Harte said.

“For the month of July, 254 m of development was completed, or 8.2 m/d. Development completed to-date has opened up several areas in the Sugar Zone deposit, particularly in the near-surface Upper Zone area, to provide early high-grade stopes,” the company said. Redpath Canada is helping the company out with underground development.

The February resource statement showed indicated resources of 714,200 oz of contained gold averaging 8.52 g/t and 760,800 oz of inferred resources grading 6.59 g/t.