Sodium sulfate plant expands into fertilizer


Construction of a $220-million expansion at Saskatchewan Mining and Minerals Inc. at Chaplin is slated to begin later this year.

The expansion is expected to be complete in late 2023 and will allow the sodium sulfate plant to produce 150,000 tonnes of sulfate potash fertilizer, or SOP, each year. This is a new product for the company and will combine sodium sulfate with Saskatchewan-produced potash.

SMMI president Rodney McCann said SOP is used mainly in fruit and tree nut crops and the bulk of production will be exported. Higher value crops like tobacco, potatoes and corn also use SOP.

“It’s basically potash without the chlorine and with a sulfur value to it as well,” McCann said. “The almond industry in California is a big utilizer of it.”

SMMI has been producing sodium sulfate for more than 70 years and controls all the commercially viable reserves in the province. Chaplin is the main operating site but the company has reserves at Bishopric, near the southeast tip of Old Wives Lake, and at Ingebrigt Lake near Fox Valley.

McCann said the margins available in the SOP market allow the company to economically harvest its sodium sulfate at Bishopric and move it to Chaplin for processing.

“The intent is to, as the market grows, look at our Ingebrigt Lake facility as our expansion would occur there,” he said. “It has the potential for us to be able to build a facility that could produce up to 400,000 tonnes per year.”

That would probably be two or three years after Chaplin is producing its new product.

The site is familiar to all who travel along the TransCanada Highway through the province. McCann said the main stockpile drivers see will possibly double in size as construction of a new processing facility and warehousing takes place.

“We will still harvest the same way,” he explained. “Everything we do on the south side of the TransCanada Highway in the lakes, and the water movement and the berm and dyke maintenance stays the same. All of our settling reservoirs stay the same.”

He uses the term harvest because he said that’s essentially how sodium sulfate is mined. It’s a once-a-year process that is highly weather dependent, similar to farming.

Fresh water and water movement in the lakes south of the highway draw the sodium sulfate up and out of the ground. As the brine gets denser it is pumped across the highway to five reservoirs at the facility.

The water in the reservoirs evaporates, depending on the temperature and the wind, and when the weather cools in the fall and early winter the salt crystals fall to the bottom.

“We pump out the water and then we push all of the salt that’s now sitting at the bottom of the reservoir up into the stockpile,” McCann said.

The company manages the water by moving it through the lake system in the spring and summer, but really needs the co-operation of Mother Nature.

“We’re limited to whatever we pump into the reservoirs,” he said. “Once it’s in the reservoir that contains as much salt as we’re going to be able to get that year. Once it cools that’s how we find out how much our harvest is.”

Water from the reservoirs is pumped back into the lakes in November and December and the process begins again the next spring.

McCann said moving to SOP will help the company weather a shrinking market in sodium sulfate as main users are relocating from the United States further south into Mexico and Latin America.

He said SMMI has been working on this. A recent demonstration project looked at using sodium sulfate to create sodium hydroxide, or caustic soda, and ammonium sulfate fertilizer as a co-product.

McCann said the construction and cost of that was too high to pursue at the time but research and development continues.

“We’re a sleepy old Saskatchewan salt mine but we’ve been investing in technologies and alternate uses of sodium sulfate for the last 15 years,” he said.

McCann said he is buoyed by support from the provincial government through changes to its sodium sulfate royalties and new incentive programs.

The sodium sulfate incentive provides a 10 percent credit for capital projects that diversify or improve efficiency. The government has also dropped the royalty rate for production from four to three percent while SMMI transitions.

The project also qualifies for a non-refundable, non-transferable 15-percent tax credit on capital expenditures under the Saskatchewan Chemical Fertilizer Incentive.

McCann said taxpayers aren’t on the hook directly as the support comes via a trailing model, that is, after the project is up and running.

About 40 people work at the plant now and that could rise to 70 with the expansion. About 360 construction jobs are also expected.

McCann added the company is proud of its role in providing world class habitat for migratory and upland birds. SMMI works closely with Nature Conservancy Canada and Ducks Unlimited to manage and maintain a good environment for birds.

“Without our water management and the way we kind of conduct our business it just wouldn’t be possible,” he said. “It’s one of those great synergies where what we do enhances the environment. We’ve even moderated or changed how we do things at certain times to support the Nature Conservancy side. We sometimes have had to limit our harvest volumes or the way we move water because that is such a core value to us.”