Kansas Underground Salt Museum

Giant underground room in the Hutchinson Salt Mine

"Back to the salt mine" usually doesn't mean fun, but dropping down into the old salt mine in Hutchinson, Kansas is actually pretty nice.

To get to the mine, an elevator drops you 650 feet down in about a minute and a half.

When the mine opened in 1923, the owner hailed it as the "most modern in the world."  Miners used what was then new technology to excavate vast "rooms" in the salt vein.  They would drill into a wall of salt, place explosives, then blast off a layer.  Big machines would crush it into gravel, then elevators would haul it to the surface.

Picking up souvenir chunks of rock salt

The method is called room-and-pillar for reasons that are pretty obvious once you're in the mine.  It's a series of enormous rooms with big pillars of salt left standing between them to hold up the roof.

The size of the rooms is amazing.  They're also cold, so if you go, even in summer, take a sweatshirt or coat.

Down in the mine, you can see where equipment scraped salt from the walls, the equipment miners used for blasting and crushing the salt, the underground rail line that hauled crushed salt to the elevators and you can pick through a pile of salt rocks for specimens to take home with you.  It's all pretty interesting.

No one is producing commercial salt from the mine anymore, but it's still in use. It's now a secure, constant-temperature, underground storage site.  It holds everything from corporation records props and prints of old Hollywood movies.

Making Salt in Kansas
People had been making salt in Kansas since the 1860s.  That mostly meant drawing salty water from marshes and springs, then evaporating off the water in kettles.  In some cases it was as simple as picking up sheets of salt left behind when salt marshes had evaporated in late summer.

Geologic cross-section from Hutchinson
to Newton showing salt bed
From: Kansas Geological Survey

But there was more salt in Kansas than met the eye.  Five hundred to 1000 feet below the surface in parts of Kansas, there's a thick bed of salt.  It formed during the Permian Period when the last remnants of an inland sea evaporated.  As the water dried up, salt that had been dissolved in the seawater precipitated out and fell to the sea floor.

Over time, new layers of rock formed above the salt, burying it deep beneath the surface.

Benjamin Franklin Mudge

In 1866, Kansas State Geologist Benjamin Franklin Mudge noted in his First Annual Report on the Geology of Kansas that Kansans were spending $80,000 a year on salt shipped from out of state.  He pointed out that Kansas had supplies of salt, and lots of sun for evaporating it from brine.

While Kansas is relying for its supply of salt on New York, Michigan and Saginaw, there is an abundance of that article within the State, sufficient, if well developed, to supply the whole valley of the Mississippi, even if it population were ten fold greater than at present.

That started a salt boom in Kansas.  The first to start a commercial operations was the Continental Salt Company in Solomon.  A few more sprang up around that one.

In 1877, a guy drilling oil stumbled onto the giant salt bed under Hutchinson in 1877.  More salt companies followed and within a few years there were dozens of them all across the region, including  Kanopolis, Kingman, Lyons, Anthony, Wellington, Nickerson, Sterling, and Hutchinson.

Grainer pan showing steam
pipes that run through brine
From:
 J. of Chem. and Metal. Eng. V. 24

Many of those early efforts made salt from brine. They pumped water through pipes down into the salt bed.  The water dissolved salt from the bed.  Once the water was saturated with salt, it was pumped back up the the surface.

On the surface, it was turned into salt by evaporating away the water.  One method was to pour it into pans, then heat the pans until the water evaporated off.  Another, more efficient, process was to pump it into grainer pans which had steam pipes running through them.  Those pipes heated the brine and caused to water to evaporate.

The quick surge in production met Mudge's prediction better than he probably intended.  Kansas may have been producing enough salt to supply the Mississippi Valley population at "ten fold greater than at present."  But the population wasn't that big and the supply quickly outstripped demand.  The price plummeted and a lot of companies failed.  By 1902, there were only ten salt companies left in Kansas.

Emerson Carey and the Carey Salt Company
When Emerson Carey was 18, he dropped out of high school in Hutchinson to start farming.  In 1885 he left farming to started selling building supplies.  In 1896 he started making ice and in 1900 he added the Carey Salt Company to his portfolio.

The salt company started out as a couple of grainer pans in the building that houseCarey's system had a series of four effects.d his ice company.  It makes sense.  Back then, commercial ice makers used steam powered ammonia compressors to freeze water. He could use excess steam from the ice making operation to heat the grainer pans.
To get the brine, he sank wells down to the salt bed under Hutchinson.

The company grew quickly and Carey built a new plant just for making salt.  He installed a state-of-the-art quadruple effect vacuum pan for drying the brine.  A vacuum pan efficiently concentrates a solution (like brine) by reducing the pressure and, as a result, the boiling point of the solution.  That means the steam pumped in to boil the solution doesn't have to be quite as hot.

A multiple effect vacuum pan multiplies the efficiency by building on the process.  The water boiled off in the first state (or effect, as it's called in industry) becomes the steam for heating the next pan (or effect).  The steam isn't as hot as the original steam used in the first effect, but it doesn't have to be: the solution in the second effect is under even less pressure so it boils at an even lower temperature.  Carey's system had a series of four effects.

An African-American inventor from Louisiana named Norbert Rillieux had invented the multiple-effect evaporator in the 1830s for processing sugar.  It was a big advance because the lower temperatures kept the sugar from scorching.  For a fascianting story, read Rillieux's biography.

In 1904 Carey organized the Grand Saline Salt Company which bought an existing salt company in Grand Saline, Texas.

In 1919, Carey and another investor started the Hutchinson Bag Company to manufacturer bags for salt.  It expanded over the years and today, under different ownership, it makes bags for food, gold and samples of oil and natural gas.

The evaporation process produces light, flake salt.  It's great for food, but not so good for other applications.  In 1922, Carey decided to add rock salt to his products.  For this, he had to mine the salt.  He sold $300,000 worth of preferred stock to finance the operation.

In 1969 the family sold off the salt company.  It had a few owners until winding up as the Hutchinson Salt Company in 1991.

In the 1950s, the Carey Company hired a photographer to document its operations.  The result is 1800 photographs.  You can see them at the Reno County Museum, or in a book called Images of America: The Carey Salt Mine.

Carey also owned Hutchinson's street car company, the Hutchinson Egg Case Filler Company, the Hutchinson Box Board and Paper Company and a lot of property.

Carey served in the Kansas State Senate from 1908 to 1916 and, in that capacity, brought the Kansas State Fair to Hutchinson.

Hutchinson Raiload

The shifting locomotive out front is GE Engine No. 2.  That's No. 2 of 3; General Electric only built three of this model.  Carey Salt used it for shifting cars over the six miles of rail line it operated around the Carey Evaporation Plant and Salt Mine.  It's an electric engine that got its power from overhead lines.

GE built the locomotive in 1919.  The Carey plant used it from 1928 until 1963.