Small and modular: The coming revolution in potash

The term Small and Modular seems to be popping up quite a bit lately. For example, the discussion of small modular nuclear reactors as replacements for Saskatchewan’s fleet of conventional coal-fired electrical generating facilities.

Why is this? In my opinion, the Small and Modular philosophy is the basis of new industry paradigms whereby a production facility is designed so that it more efficiently exploits a niche market (think craft beer versus large industrial breweries) or is it more environmentally sustainable (think a small nuclear reactor versus coal-fired powerplants). Small and Modular also removes barriers to entry such as start-up capital (think setting up a shop in your garage to build garden boxes versus having to buy land, a shop, and a myriad of new tools to mass produce them).

Some things by their very nature do not make for good Small and Modular, like designing a rocket system to transport humans to Mars; however, even in the space transport sector, there are aspects of the rocket business that scale well (think SpaceX and Blue Origin versus NASA).

Where else can this philosophy be applied? I can think of one big Saskatchewan industry—potash!

When you think of potash, you think of the large facilities spotted along the Yellowhead Highway, or at Belle Plaine, and more recently, west of Bethune along Highway 11. Over the past five decades the right size to build a potash mine has evolved from about a million tonnes circa the early 1960s to three million tonnes or more, which is the current design paradigm.

Do mines have to be big? Better yet, is there a business case for returning to the one million tonnes or less paradigm?

Most of the reasons for building big potash mines are related to the realities of how potash is mined. To understand this, here is a very brief description of how potash is found in Saskatchewan.

Potash is not a big lake of the stuff, but rather a sequence of interbedded layers of valuable potash mineral (a rock called sylvinite) and next-to-worthless rock salt, or halite. In Saskatchewan, a geologist can map out at least four or more of these seams. A mining company only want the valuable stuff, so current mines are built to remove the highest-grade potash seams and leave the worthless or low-grade rock behind.

There are two ways to do this. The first is to dig a vertical shaft down to the level of the high-grade seam, then send out machines to physically chew up the good stuff, then use conveyors to bring it to the shaft then up to surface. The second is to drill vertical wells from surface to the base of the lowermost seam, then use fresh water to dissolve out the entire sequence of sylvinite and halite.

Both are tried and true technologies and go back to the late 1950s. But there are two big problems associated with these types of mines.

The first is that both technologies are very expensive, so big mines are required to recover the costs associated with building either traditional underground mines or solution mines. I don’t know about you, but I don’t have billions of dollars sitting around to use to enter the potash mining business!

How expensive is it? In August 2021 BHP Billiton announced its decision to build Phase 1 of its Jansen mine. The cost at the time was $5.7 billion USD for 4.37 million tonnes per year of potash production, in addition to $2.97 billion USD already spent on shafts and infrastructure. That’s almost $8.7 billion.

You need very deep pockets to fund that!

The second problem is that these mines are not the most efficient way of exploiting our province’s resource. An underground mine can only remove one of the four or five seams due to the tendency of potash to flow and collapse, and of the seam itself, some 70 per cent must be left behind to prop up the network of tunnels. This means at best, maybe 10 per cent of the resource is mined.

Solution mines are a bit better since they take out everything and don’t need as much propping up, but this creates another problem: lots of fresh water is needed to dissolve the mixture of good potash and bad waste salt. Also, natural gas is needed to evaporate all the fresh water used to dissolve the salt and potash in the first place.

It comes down to this: if you want to build a traditional underground or a conventional solution mine, the cost requires the mine to be big, and with this, acceptance of the problems associated with such methods.

However, there is a third way based upon Small and Modular design principles. New technologies based upon what us techies call selective solution mining, modular mine and facility design, and incorporation of more environmentally sustainable water and energy sources, allow for the bringing back of one million tonnes or less mines.

How does Small Modular Potash (SMP) work? It’s a blend of underground and traditional solution mining methods. Instead of digging a vertical shaft, an oilfield drill rig drills a vertical hole into the high-grade seam. Then a horizontal hole is drilled out from the vertical hole along the high-grade seam, thus replacing the mining machine. A series of such horizontal holes replace the grid of tunnels that form the underground mine. Salt water is used to leach out the potash, with the resulting brine returned through other wells back to surface, thus replacing the conveyor belts and hoists.

Combining existing oilfield technology with advanced potash chemical engineering allows this third method, SMP mines, to compete against the big mines. Whereas big mines cost well over $1,000 per tonne to build, SMP
mines are well under that amount. Since salt water is used to dissolve the potash, much less fresh water is required in the mining process. Finally, since there is no need to keep the underground workings open, the entire
process can be repeated at the next level of high-grade potash, meaning the mine now removes 70 per cent or more of the potash underground rather than 10 per cent.

Where can SMP take us, as a province? I believe potash is one of the best resource businesses out there, with Saskatchewan being the best place in the world to build that business. Imagine what deployment of five, ten, fifteen SMP mines would mean to our oilfield service and supply sector. Imagine if a First Nation could mine its own potash endowment for its own benefit. Imagine if entrepreneurs could invest in a business that lasts decades, if not centuries. With our province’s prosperity so closely tied to our natural resources, just imagine where SMP can take us.

A resident of Martensville, Sask. and a professional geoscientist registered in Saskatchewan and frequent contributor to this magazine, Steve Halabura has 40 years + of experience in developing Saskatchewan’s resources. Potash has been one of his passions since 1989 and he is presently a co-founder and CEO of Buffalo Potash Corp., a bona fide “Small Modular Potash” company.