GranCem: Refining Cement It's not that often the words 'something new' come up when one talks about cement. Holnam, however, changed this tradition with the introduction of GranCem, the company's newest cement product, at this year's CONEXPO-CON/AGG show in Las Vegas, Nev. Created from ground granulated blast furnace slag, and used in combination with portland cement, GranCem is said to produce concrete with an increased durability, strength, and workability.

GranCem is produced from the following process: after being ground into a fine powder, the granulated blast-furnace slag is mixed with water and portland cement (the traditional way GranCem is used). When the concrete sets, it hardens into a solid monolithic mass. The hydration reaction then forms a gel-like material called calcium silicate hydrate. This material is typically finer than Type I portland cement, comes in an off-white color, has a density of about 2.88, and is handled and dispensed like common portland cement.

Holnam says that GranCem can be used both as a raw and as a finishing material for a wide variety of commercial and architectural concrete applications. World-renown architect I.M. Pei chose to use GranCem in his final work, the Rock and Roll Hall of Fame in Cleveland, Ohio.

According to Holnam, the nearly white finish is so well cured that it's not only brighter than common portland cement, it has a look that would be nearly impossible to obtain through the use of any other cement product. Good concreting practices, however, are necessary in order to achieve desired results. One must pay considerable attention to formwork, batching, mixing, placing, finishing, and curing when using GranCem.

TXI to expand Midlothian plant, wins TNRCC permit On March 22, TXI broke ground for a new kiln system that will make its Midlothian plant the second-largest cement producing facility in the United States. The kiln system will increase the plant's capacity from 1.3 million tpy to 2.8 million tpy. According to TXI, the $200 million project will include the most advanced pollution system in the United States and will enable TXI to expand production without an increase in emissions. Construction is expected to be completed by fall of 2000.

In addition, TXI Industries was recently granted a 10-year permit by the Texas Natural Resource Conservation Commission (TNRCC) to continue its resource recovery program at the Midlothian cement plant. Administrative law judges had recommended in January that the TNRCC grant the permit. Stack tests have shown that TXI's program's use of flammable liquids as fuel, instead of coal, has reduced total emissions as much as 68%. TXI began the resource recovery program in 1987. Fifteen additional cement plants across the United States also operate similar programs, two have permits and 13 are under interim permits granted by the Environmental Protection Agency.

Lone Star to convert Indiana plant to semi-dry process Texas-based Lone Star Industries will purchase a new production line for its existing Greencastle, Ind. plant. The new line will convert its present production system from the traditional wet process to the semi-dry process, thereby increasing production from 2,000 to 3,600 tpd. The cost of the new line will be about $33 million, and delivery will begin later this year with plant start-up expected to start in spring of 2000. Fuller will be the supplier.

Cementos Progresso's new 3,000-tpd plant on stream Last year the Guatemalan cement producer Cementos Progresos S.A. successfully commissioned its new San Miguel production line. The plant is equipped with two upgraded kilns and a roller press-based cement grinding installation. The new 3,000-tpd production lines doubles the capacity of the San Miguel plant which went on stream in 1974. F.L. Smidth was the supplier.

Cement Americas on the web Cement Americas will soon be accessible on the World Wide Web. By logging onto www.cementamericas.com, those interested in the North, Central, and South American cement industries will be able to obtain current and breaking industry news, as well as a complete list of industry links; new product information; a calendar of upcoming events; details on International Cement '99 at Walt Disney World in Orlando, Fla.; information on the North American Cement Directory and its companion map; subscription forms; and advertising and marketing information.