Legacy Project Celebrates Early Cavern Development Milestone

Mon Jun 01 00:25:00 CEST 2015

K+S Potash Canada’s (KSPC) Legacy Project reached a major milestone on March 5 when the mine began developing the caverns that will supply potash-rich brine to the process plant.

“On March 5, we began mining,’’ says Trevor Dyck, Production Manager for KSPC. “We’re not shipping product yet – that’s coming. But we are mining. And for me, that’s super exciting.’’

The milestone is called, “early cavern development’’ and it’s taking place 1,500 metres (one mile) underground in the ore zone. Each cavern is developed using the mine’s powerful waterworks system to inject fresh water and pump out the resulting brine through two boreholes situated 80 metres apart. This flushing action erodes the water-soluble salt and potassium and ultimately results in connecting the two boreholes to form a single cavern. Each cavern must be “grown’’ large enough to supply “feed’’ to the process plant. It’s a ramping-up process that will see 36 caverns ready to feed the plant by the time the Legacy mine goes into production.

“We’ve made a transition here from a design-engineering-construction project to one where we’re in the early stages of operating a plant,’’ says Dyck.

Construction, engineering, commissioning and operational readiness teams from KSPC and Amec Foster Wheeler, the Legacy Project management company, celebrated their collaborative achievement March 5 at a gathering in Bethune, Sask.
Darren Hrynkiw, Manager, Wellfield for KSPC, oversees the operation of the wellfield, where drilling rigs on wellpads created wellbores that tap into the underground resource. A network of pipelines and related infrastructure are used to circulate fresh water through the developing caverns and return the resulting brine to the tank farm. Once the caverns have been developed to a sufficient size they will be ready to return brine to the process plant. 

“There’s a good deal of time required to grow these caverns until they’re substantial enough in size,’’ says Hrynkiw, adding that the process takes about a year. “That’s why, even though we’ve now officially started up, we’re not yet making potash.’’

Preparing all the new equipment and other assets required to bring the mine into operation was a task demanding close cooperation among many people and departments. The failure rate of new equipment – what maintenance experts refer to as “infant mortality’’ – is significantly higher at start-up operations than at existing mines where assets have been regularly maintained. That’s why Marc Colombet, Maintenance and Reliability Manager for KSPC, had mixed feelings when mine operators “hit the switch’’ on March 5.

“We were nervous because you never know what can happen – you know that you will have some trouble,’’ says Colombet. “But there was more excitement than nervousness. Our team was very, very excited.’’

Colombet’s job was to design and implement a maintenance and reliability strategy that ensures “we manage the asset and that we will not be managed by the asset.’’ This involved a good deal of training and getting to know all the equipment by measuring vibrations, temperature and noise, as well as analyzing the equipment’s oil in order to detect as soon as possible any hint or clue something might go wrong. Colombet says it took about four weeks to iron out the biggest issues arising from startup.

“Our team is fully and completely in operation mode now,’’ he says. “We know the equipment, we know the people and we know the organization. The stress from the startup period is over.’’