By Melanie Franner
It’s been many years since the New Brunswick Department of Natural Resources first discovered potash in the Plumsweep-Penobsquis area in 1971 and subsequently granted the exploration and development rights to the Potash Company of America. These operations were acquired in 1993 by Potash Corporation of Saskatchewan Inc. (also known as PotashCorp) and the facility was renamed PCS (New Brunswick Division) Inc.
The next few years saw potash deposits discovered in the Cassidy Lake and Lower Millstream areas. The Cassidy Lake deposit eventually went into production but was closed in 1997, while the Millstream deposit has yet to be fully explored.
Prime time at Picadilly
Today, potash mining in New Brunswick accounts for about five per cent of all potash production in the country. And PotashCorp continues to be a major player in the province. The company has continued to mine Penobsquis, which has been producing approximately 800,000 tonnes of potash per year and approximately 600,000 tonnes of salt per year.
A new deposit, however, was discovered in 2002. This Picadilly deposit, as it is known, is located approximately one kilometre south of the existing Penobsquis mine.
Subsequent exploration showed that this new deposit offered a potentially significant reserve. As such, work soon got underway. Mining feasibility studies were completed in 2007 and environmental approval came in 2008.
PotashCorp announced a $1.7 billion project to access the new Piccadilly deposit in 2007. But the deposit proved to be more geologically complex than first thought.
“There were some challenges along the way,” states Mark Fracchia, president of the potash division of PotashCorp. “It took longer than first expected to sink the shafts. This is a complex job that not only requires the excavation, but also installation of concrete linings through varying geological conditions and water-bearing formations. There are many variables and the process requires constant management to maintain control over the materials and schedule.”
FCC Construction, of the OSCO Construction Group, was charged with managing the construction for the two new headframes required for the expansion project. According to the company, the foundation for the production shaft headframe was done inside a secant pile wall because of an anticipated inflow of groundwater. The wall itself was constructed of three-foot-diameter concrete caissons, drilled and socketed into the bedrock, and overlapping each other to create a retaining and water-cutoff wall. The excavation work was done inside the wall. Both headframes have 60-feet deep foundations, while the excavations required moving in excess of 55,000 cubic yards of material. Both foundations also required placement of 10,000+ cubic yards of concrete.
“The total cost of the Picadilly mine is estimated to be $2.2 billion,” states Fracchia, who adds that about half of that was spent through local vendors. “It is estimated that 11,000 new jobs were created during the construction phase and the mine is expected to employ around 450 and 500 full-time workers.”
Once fully operational – production is expected to ramp up over the next two to three years – the Picadilly mine is anticipated to have an operational capacity of up to 1.8 million tonnes of potash per annum.
“The anticipated life of the Picadilly mine is more than 30 years,” states Fracchia, who adds that production at the Penobsquis mine will slowly be phased out as Picadilly ramps up.
Although located relatively close to each other, the Penobsquis and Picadilly mines will require different mining techniques.
“At Penobsquis, the ore body is on a relatively steep slope, so it is mined using a cut-and-fill method,” says Fracchia. “This means a mining room, or panel, is cut with a continuous miner, then backfilled with salt tailings. The miner then cuts above the backfilled room and the process is repeated following the angle of the ore body. At Picadilly, the ore body is more horizontal so it will be mined using a more conventional long-room and pillar-mining technique. Continuous borers cut a first pass, turn and cut a second pass adjacent to the first. They then cut subsequent passes below the first, following the thickness of the ore seam.”
The Picadilly mine is considered to be well located – with ready access to port facilities – to service many of PotashCorp’s customers in the U.S. and Latin America.
“Latin America, particularly Brazil, is a growing market for us,” states Fracchia. “The U.S. consumes about 9.5 million tonnes of potash annually, while Latin America consumes about 11.7 million tonnes.”
Despite a reduction in global commodity prices, international demand for potash during the first half of 2015 has remained strong – with PotashCorp experiencing record shipments to offshore markets.
“Despite the near-term macro-economic challenges, PotashCorp remains optimistic about long-term demand for potash, particularly in light of forecasts that suggest the world’s population could reach more than nine-billion people by the year 2050,” says Fracchia.
A financial win
The Picadilly mine officially began operations in October 2014 to much excitement and fanfare. But there may be more excitement still to come. The New Brunswick government recently issued an RFP for the potash exploration rights in Salt Springs, an area located adjacent to the former Cassidy Lake potash mine and less than 60 kilometres northeast of the Port of Saint John.
“We put out the RFP to see what the level of interest is,” said Energy and Mines Minister Donald Arseneault, who admits that the responses included those from several companies around the globe. “Unfortunately, some companies have since pulled out because of the downturn in the potash market. I want to get the biggest bang for our buck, so I believe it is in our best interest to wait until the market conditions pick up again and then issue another RFP.”
Minister Arseneault knows of what he speaks.
“The Picadilly mine is special to me,” he adds. “I was Minister of Natural Resources back in 2007 and was one of many people who helped convince PotashCorp to commit. There is no doubt that Picadilly mine will have a tremendous economic impact on our province.”by