Environmental Progress - Fall 1998

Even the Brick Is Special at New Agency Headquarters

Breakthrough bricks bake the sulfur inside to protect the environment -- and guess where some of them are in use!

No one knows for sure when someone first realized that shaping a glob of mud or clay into a rectangle and letting it dry in the sun provided a dandy item for building a wall, a fortress or a palace. Over the centuries the process stayed pretty much the same, with clay being molded into uniform shapes and baked by processes that changed as technology improved a bit from time to time. In northern Illinois recently there have been some major changes in that time-honored process. At Marseilles Brick, located at Marseilles in LaSalle County, a revolutionary new process is making handsome bricks while keeping tons of sulfur out of the air, conserving natural resources and giving a shot in the arm to the brick-making industry around the nation. The secret lies in sealing potential polluting emissions right into the brick by adding careful amounts of some rather common substances to the basic clay. The bricks even come in colors. Color, in fact, is what started the whole process. In 1987, five imaginative people recognized a potential market for architectural brick in the greater Chicago area and pooled their resources to build an environmentally friendly plant. Mark A. Martin, environmental protection engineer III in the Bureau of Air's permit section, says the Marseilles plant is the first new (greenfield) brick plant erected in the U.S. in more than 40 years. The process design and most of the equipment were purchased in France. The final cost of nearly $14 million dollars left the builders without funds to continue and the plant was sold. In Chicago, designers and builders were demanding buff, pastel and nearly white brick, which in turn demanded new and different clays. The clay was there, but it contained large amounts of pyrite (iron sulfide) that broke down and generated unacceptable amounts of black smoke during firing, had the potential to emit more than 400 tons of sulfur dioxide through the stacks each year and could result in high numbers of inferior bricks that would have to be rejected. The operators looked at scrubbers to control their smoke and emissions problems.

Traditional scrubbers work well, but they would waste 30 to 40 million gallons of water yearly.

Traditional scrubbers deal with stack emissions quite well, but they would waste 30 to 40 million gallons of water each year at the new plant, generate truckloads of waste sludge that would have to be landfilled, would consume large amounts of lime and acid neutralizers and wouldn't solve the brick quality problem. In a major technological breakthrough, the company tried putting fine ground lime (calcium carbonate) into the unfired brick where it reacted during firing to create a "friendly" sulfate that stays in the brick. Fine tuning showed that adding silica sand helped oxygen penetrate the brick during firing and formed a glassy seal to keep sulfate compounds within the brick.

Extensive testing at Clemson University, where one half a brick would be fired and the amounts of sulfur in the fired and the "green" halves would be compared, demonstrated that the sulfur was indeed being contained in the brick. Stack tests verified that emissions were meeting Illinois EPA requirements. The sulfur wasn't going up the stack. And the bricks were high quality.

Waste heat is recycled through the operation.

The plant has a number of other environmental pluses. Martin says by housing the kiln in a "vacuum bottle" type structure, waste heat can be recycled into the pre-heat area, the dryers and holding room. The kiln is super insulated to save energy. Relying on state-of-the art automated technology, Marseilles Brick can produce 36,000 bricks an hour, or more than 55 million bricks a year, in an operation that employs only 42 people. James R. Johnson is general manager and Jock Laird is plant manager. From the time the clay is dumped from the trucks at the crushing plant until bricklayers at a construction site unpack the bricks for use, no one touches the clay or handles the bricks. Understandably, Marseilles' encapsulating technique is attracting industry attention around the nation, and other plants are now being designed to utilize the method. The process has a special significance to the Illinois EPA. Asked to identify a Marseilles brick user in downstate Illinois, the company searched its records and found that the Illinois EPA had used Marseilles' Colonial Sand bricks in the new building erected to expand the remodeled old manufacturing complex that is its new home. To paraphrase an old bromide, "the brick stops here."