Geologists want to know if enough limestone can be found in eastern North Dakota to run a profitable cement plant. It’s a subject of intense interest in North Dakota’s construction industry, which has seen the cost of cement rise sharply because of increased demand.

Greg McCormick, a spokesman for Northern Improvement, one of the region’s largest highway construction companies, said the cost of cement has jumped from US$100 a ton to about US$125 a ton in the last few years. During last year’s construction season, North Dakota companies had trouble getting enough cement to meet their needs, McCormick said.

Ed Murphy, North Dakota’s state geologist, said a North Dakota company is interested in building a cement plant in the Red River Valley, near a rock formation called the Niobrara. Murphy said the unidentified company that is interested in North Dakota cement manufacturing plans to use urea pellets from animal waste, or carbon dioxide from North Dakota’s power plants, to raise the calcium carbonate level in the mix.

Paul Chale, LaFarge Dakota’s general manager, said the company should be able to supply its customers with enough cement this year. Last year, LaFarge Dakota had to limit the amount of cement customers could buy, he said.

Cement producers have tried before to use North Dakota shale to make cement, Murphy said. The state’s first cement operation was in the Cavalier County town of Concrete, in the 1890s and early 1900s. Limestone used at the plant were less than 70 percent calcium carbonate, and it takes 80 percent calcium carbonate to make Portland cement, Anderson said. The company marketed its product as natural cement, but it could not compete and was eventually shut down.

The Lehigh Cement Co also explored putting a cement company in North Dakota in the 1960s. LeHigh decided the shale’s calcium carbonate level was too low, and it would be too costly to add outside sources of limestone to meet Portland cement standards, Anderson said. "We’ve done a lot of investigative work over the years, but there’s so much more we could do," he said.