The products made at Snow Shoe Refractories in Clarence can really take the heat.
“Refractory products are materials that can withstand extreme heat and corrosive environments for the purpose of containing something,” said Mark Jacobs, technical manager at the refractory.
The refractory employees more than 40 workers, most of whom make ceramic firebricks used for a multitude of purposes — from industrial use holding molten metal in steel mills and caustic products in the stone and lime industry to lining residential wood burners and furnaces. The most heat resistant products can take temperatures of up to about 3,500 degrees, Jacobs said.
The refractory has been at the site since 1924, operations manager Marty Wesley said. The location was a logical choice. Raw materials were readily available from the local coal industry. Clay brought to the surface with the coal was used to make the bricks and the coal was used to fire the kilns, Wesley said.
Today, natural gas fuels the fires, and raw materials, which are stored behind the refractory, come from all over-
Imported Chinese bauxite is the primary material and is used in 70 percent of the items produced in Snow Shoe, Jacobs said. In a throwback to days of yore, the second-most prominent product is clay from coal operations in Clearfield County. Materials from Georgia and Alabama are also used.
The process of making firebricks takes about four days, Jacobs said, and starts when the ingredients are crushed and then mixed together. The ratios of the raw materials depend on the product being made.
From there, the mixtures are fed into presses that churn out five bricks a minute, Wesley said. The bricks are removed from the presses and stacked by hand. They are also periodically checked by a lab technician to ensure they are maintaining the proper weight and shape, but Jacobs said the workers moving the bricks can tell if the products aren’t quite right.
“A lot of these guys have been doing this for 20 or 30 years,” he said. “They can feel it if it’s getting light.”
The presses are a link to the industry’s past.
Jacobs said many refractories now use hydraulic equipment, but the equipment at Snow Shoe is still mechanical and was produced and installed in the late 1940s or early ’50s. Some smaller products are still made by hand in wooden molds, Wesley added.
After being pressed, the bricks have to be dried for about 24 hours. This is an important step because, if the products have too much moisture in them, they can explode when they enter the kilns, Jacobs said.
Once dry, the bricks are ready to be fired. This process takes 25 hours, Jacobs said. Kilns are set at 300 degrees at first and eventually ramped up to between 2,400 and 2,700 degrees for the last 10 hours of the process. After just more than a day in the heat, the bricks cool for 24 hours.
After cooling, the finished product is taken to a warehouse and shipping area. Most goods are made to order and shipped soon after completion but a stock of some items is kept on the premises, Jacobs said.
Since 2007, about 8,000 products differing in shape and size have come out of the kilns, he added. Some are made all the time and others are less commonly ordered and only produced every two to three years.
About 5 to 10 percent of the items are sold in Pennsylvania, Wesley said, with some purchased as close to home as Graymont in Pleasant Gap and Standard Steel in Lewistown. The refractory has also sold to Exxon Mobil and to companies in other countries.
Wesley, an employee at the refractory since 1988, said the work has been gratifying. The operation is small compared with other refractories and has survived recessions and changes in the market because of the quality of the product produced there.
“It’s been very rewarding,” Wesley said. “I’m passionate about it.”