Even before the Civil War, limestone quarries punctuated the landscape in and around the city of Piqua, Ohio. The rich layers of high-quality stone, covered by only a few feet of earth, were readily accessible, tempting a large number of entrepreneurs into the quarry business. Operations were small and restricted to one or two commercial products. Nearly all produced building stone which moved both north and south by canal boats on the network of man-made waterways connecting the central Ohio area to navigable rivers. Other early products were crushed stone, burnt lime and foundry stone.
No single firm emerged from the pack until near the turn of the century. In 1894, what might have been nothing more than a minor incident changed the course of limestone production in the area. A Mr. Coffield, who operated a small limestone kiln, had bought a safe from the Hall Safe Company in Cincinnati and was slow in remitting. The safe must have been expensive, because A. Acton Hall himself journeyed up from Cincinnati to collect. Instead, he formed a partnership with Cincinnati friends and bought the entire operation, presumably including the safe. The new venture was christened "The Ohio Marble Company."
During the next couple of decades, Mr. Hall, who assumed management of the operation, bent his efforts toward acquiring new processing equipment, new properties, and starting new products lines. When he died in 1923, his wife, Mary succeeded him at the helm and continued his program of modernization and expansion. A pulverizing plant was installed to produce industrial and agricultural limestone products. A crushing plant was added and the company set up a subsidiary to market bird grit in one pound boxes to canary fanciers and in two-hundred-pound burlap bags to poultry farmers.
The company was directed by the Hall family for more than fifty years. One of the last projects completed under the direction of Mary Hall was a battery of ball mills and air-separation equipment to produce limestone whiting, which proved an ideal filler for rubber goods-footwear, housewares, lawn and garden equipment, recreation equipment and automotive parts.
In 1951, Armco Steel Co. acquired the company to supply flux stone to its steelmaking facilities in southern Ohio and eastern Kentucky. By then, the product line was substantial. It included stone products such as railroad ballast, landscape chips, riprap, cupola flux and crushed stone; agricultural products for soil and lawn conditioning, fertilizer blending and livestock feed; and a number of industrial products. Armco retained most of the active product lines along with increasing flux stone production. As flux stone was gradually superseded by quicklime from another Armco facility, investment in pulverizing and classifying equipment increased to expand production of high-quality fillers for the plastics and rubber industries. This expansion included a pair of classifiers to enable existing equipment to produce fillers down to an average size of three microns.
In October 0f 1989, the company was purchased from Armco and is now privately owned. The new company, Piqua Materials Inc., has maintained the tradition of upgrading equipment and processes so as to remain a reliable source for industrial fillers. In 1995, Piqua Materials installed a new Sturtevant Sidedraft Air Classifier to increase its production and quality of limestone whiting. In recent years, whiting - now known as Piqua Mineral Filler 70 - is finding widespread use in mastics, fiber reinforced plastics and many other applications. Piqua Materials is now in the middle of a multi-million dollar project to increase its stone crushing capabilities which will insure its supply of stone, agricultural and industrial products well into the new century.