The History of the National Slag Association


During the Industrial Revolution, now also known as the First Industrial Revolution, one of the important technological developments was in iron making where the substitution of coke for charcoal greatly lowered the fuel cost of pig iron and wrought iron production effectively allowing larger blast furnaces that resulted in economies of scale.  Although slag use in masonry work was already well underway, the increased production of slag at this time allowed for its utilization in road building such that the first slag road was built in England in 1813. Seventeen years later, the first slag road was laid in America, and by the year 1880, blocks cast of slag were in general use for street paving in both Europe and the United States.  Other uses for slag at the time were as track ballasts for the nations rail roads.  The Second Industrial Revolution, also known as the Technological Revolution, was a phase of rapid standardization and industrialization springing from a new group of innovations during the late 19th century into the early 20th century.   These new innovations included new steel making processes such as the Bessemer process that allowed for the mass production of steel from the molten pig iron before the development of the open-hearth furnace.

In 1904 the first known technical paper on Blast Furnace slag was presented during a meeting of the Engineers Society of Western Pennsylvania by a Mr. James A. Shinn.   The author discussed his interest in utilizing slag as a raw material for the manufacture of cement based on his experience as a manager at an early Portland cement works at Wampum Pennsylvania.   The steel industry was now beginning to recognize that iron and steel slag products were versatile materials that could be utilized in other applications.  One of the most important contributions to follow toward promoting slag by the steel industry was provided in a paper entitled “ Utilization of Iron and Steel Works Slag” that was presented at a regular monthly meeting of the Engineers Society of Western Pennsylvania in 1915 by E.C. Brown, Chief Engineer, Carnegie Steel Company.  At this time there were only a few scattered plants built for processing slag, and transportation of these products was predominantly by railroad at practically no cost.

Challenges Surrounding the Transportation of Slag

On June 17, 1915  the Interstate Commerce Commission (ICC) published a rule that prohibited the free hauling of slag by railroads.  The ICC was a regulatory agency in the United States created by the Interstate Commerce Act of 1887 but was later abolished in 1995.  As a result of this ruling, the steel companies with increased production of iron and steel began in earnest to do something about providing outlets for the slag products, and within a short time slag processors were establishing plants in various areas of the United States.  The slag processors also began to face increasing resistance to acceptance of slag in other uses outside of macadam and many of these slag companies undertook ambitious programs involving laboratory and field investigations to help promote these products.  At this time the individual companies had been going their own ways to promote slag utilization, but it became increasingly apparent that a pooling of these efforts would be more effective and much more economical to win the desired status for slag acceptance.  The nation during this period was producing 40 million tons of pig iron a year with a concomitant output of 20 million tons of slag.  At the same time, another problem the companies were facing, particularly during the latter part of 1917, was the car shortages for hauling slag due to the heavy demands for freight shipments to serve the war effort.  Some of the companies were sending representatives to Washington to get relief on car assignments, and on one of the visits Harry Love, then of Standard Slag, was advised that the industry would have better success when making requests to address the challenges they were facing due to the war effort if they became organized as an independent group.

Formation of The National Slag Association (NSA)

On January 16, 1918, an organizational meeting of slag processors was scheduled at 3:30 pm at the Chittenden Hotel, Columbus Ohio.  A total of 13 slag processing companies were represented at this meeting in addition to press and trade journal representatives from Rock Products and Building Materials, Pit and Quarry, and staff from the Ohio State Journal.  An additional five slag processing companies were reported without representation.  The slag processing companies present at this meeting voted unanimously to form the National Slag Association (NSA) and elected a President, Vice President, and Secretary/Treasurer to serve as the Executive Board.   The first headquarters of the NSA were established at 933 Leader-News Building, Cleveland Ohio and a Board of Directors comprised of individuals from the following Companies was created:

The Birmingham Slag Company, Birmingham, Alabama

The Buffalo Slag Company, Buffalo, New York

Carnegie Steel Company, Pittsburgh, Pennsylvania

Cleveland Macadam Company, Cleveland, Ohio

Duquesne Slag Product Company, Pittsburgh, Pennsylvania

Illinois Improvement and Ballast Company, Chicago, Illinois

Island Slag Company, Buffalo, New York

National Slag Company, Allentown, Pennsylvania

Philadelphia Slag Company, Philadelphia, Pennsylvania

Standard Slag Company, Youngstown, Ohio

In 1929 the association realized that providing data on the properties and behavior of slag would require the combined effort and all the available technical talent in the association.  It was therefore decided that a technical problems committee be formed.  This committee was tasked with all aspects of development affecting the use of slag, identifying the knowledge gaps concerning the use of slag, outlining programs of research on slag, conducting and supervising these programs, and reviewing and approving any and all publications on research, test programs, and articles related to slag utilization and application.  Due to the numerous interactions with various agencies and institutions in the nation’s capital, the NSA headquarters was moved to the then Earle building, now the Warner Building, in  Washington DC in 1934.  In 1946 at the behest of the U.S. Bureau of Mines, an NSA sponsored safety contest was held for plant employees to promote safe working conditions within the plants.  This was the advent of the NSA Safety Committee.  In 1959 the NSA Operators Committee was formed to promote an exchange of ideas and seek solutions to operational problems within the industry.  Over the next six decades additional committees were formed as a part of the larger National Slag Association such that today the NSA currently headquartered in Coatesville Pennsylvania, is comprised of committees that include the Technical, Environmental, Marketing, Safety, Operations, Purchasing, and Allied member committees.  The NSA consists of over 80 different member companies directly or indirectly associated with the production and processing of iron and steel slag products.  Additionally a strong collaboration between the NSA and other industry groups that include, The Steel Manufacturers Association (SMA), The American Iron and Steel Institute(AISI), The Slag Cements Association (SCA), Euroslag, The Australasian Slag Association and the World of Iron & Steel Slag network, ensures that there is a vehicle for the exchange of ideas that promote the increased utilization of these versatile iron and steel slag products.