When Global Stone PenRoc Inc., unveiled its $1.8 million limestone roofing filler plant Oct. 3, 1997, at an open house and ribbon-cutting ceremony at York, Pa., the event brought sudden prominence to the low-profile activities of a major industrial minerals producer.

Global Stone PenRoc Inc. is a wholly owned subsidiary of Global Stone Corp., Oakville, Ontario. In less than five years it vaulted to fifth place on the list of top North American lime producers. Formed in 1992, Global Stone Corp. is a public company listed on the Toronto Stock Exchange.

At York, Global Stone PenRoc operates three high-purity limestone quarries, three filler/whiting grinding plants and a construction aggregates plant. Approximately 1 million tons of limestone are extracted annually for processing into calcium carbonate fillers and whiting for floor tiles, roofing, paint, carpet backing, fiberglass, sheet vinyl and crushed stone products for the construction industry.

Global Stone PenRoc's principal marketing area extends from Virginia to Chicago to New England. Parent company, Global Stone Corp., has eight operating sites in Ontario, Tennessee, Virginia, Michigan, Pennsylvania, and Oklahoma.

Processing overburden The new filler plant is targeted to produce more than 250,000 tpy of limestone fillers for asphalt roofing to meet the requirements of a major, long-term contract. The limestone feed is derived from limestone overburden, which is mined to uncover high-purity sources.

Until the plant opened, the principal use for the limestone overburden was for crusher run fill and sized aggregate products. Large quantities of sand and screenings have been stockpiled and are available for plant feed.

The plant was constructed near an existing high-purity filler plant, adjacent to rail and highway loading facilities. It was designed by retired Chief Engineer William Devitt for fully automatic operation with optional manual control.

Operating from nearby stockpiles, a wheel loader operator charges a 300-ton feed hopper over an inclined belt conveyor, which transfers the feed to a 250-tph rotary dryer. These components were taken from obsolete plants and refurbished prior to installation.

Dried feed is elevated to a 300-ton storage bin that feeds two triple-deck screens. The portion of the feed that is minus 30-mesh is taken out as product at this point. Oversize (plus 30-mesh) goes to another storage bin that feeds two 66-in. roller mills capable of producing up to 50 tph of minus 30-mesh product. From here, the product passes through two double-deck scalping screens which ensure that no plus 30-mesh material is in the final product. Typically, 40% of the incoming feed passes the screens and 60% requires grinding.

Material from the grinding circuit is then mixed back in with the unground material and collected in a 24-in. underground screw conveyor that runs the length of the plant. At its end, specification filler is elevated to either of two 1,000-ton storage silos-one for loading pneumatic bulk trucks and the other for loading railroad cars.

All equipment is sealed to minimize emissions. The dryer has its own cyclone and baghouse while the mills and screens inside the plant are serviced by an elaborate dust and vapor collection system.

NSA president praises Globe The new filler plant was officially dedicated Oct. 3, 1997, at a ribbon-cutting ceremony. National Stone Association President Joy Wilson cut the ribbon aided by Global Stone Corp.'s David Singleton, CEO; Danny Shepherd, general manager, eastern region; and William Vest, vice president and general manager of Global Stone PenRoc Inc.

"An outstanding NSA member, Global Stone has highlighted in its new filler plant some guiding principles of the National Stone Association," Wilson said. "One is to find the wisest use of our natural resources, which in this instance is to increase the value of mined overburden. Another is the recognition that technological progress cannot come at the expense of environmental issues or community concerns. This is evident in the new plant which is totally state-of-the-art and self-contained.

"A third principle is that our industry depends upon management skill and technical innovation to maintain growth and profitability. NSA appreciates Global Stone's leadership in these areas."

The birth of a company Although Global Stone Corp. is only 5 years old, an earlier chain of aggregate-related moves had prepared the company's management for the role it plays today.

"In the mid-1960s, UK's Consolidated Gold Fields PLC (ConsGold) diversified into construction aggregates, with this activity eventually becoming known as Amey Roadstone Co. (ARC)," Singleton said. "I joined the company in 1964 from a background in civil engineering. Through acquisitions and development, ARC became the largest aggregates producer in the UK and the fifth largest producer in North America.

"In 1989, when Hanson PLC took over ConsGold, ARC was reported as contributing half the total profit of ConsGold. At the time I was managing director of UK operations for ARC. In 1990, under amicable circumstances, two key ARC executives joined me in creating Federated Aggregates, a new company patterned after the former ARC. Those people -Herb Wilson, chief operating officer, Mike Niblett, chief financial officer-and myself were principally responsible for the launching of Global Stone Corp. in 1992.

"More recently, Danny Shepherd joined Global Stone as general manager, eastern region and all have contributed to the exceptional rate of growth achieved.

"In the fall of 1992, having formed an alliance with Cominco Ltd, a major Canadian-based metals producer with an interest in diversifying into construction materials and industrial minerals, we purchased a limestone quarry and lime works at Ingersoll, Ontario, which held a long-term lime supply contract with its former Stelco owner. During this period, Cominco provided significant support and we launched GSC as a new public company with an initial public offering on the Toronto Stock Exchange in May 1993."

According to Singleton, the company was formed to become a highly focused, limestone-based natural resources company with the aim of achieving total North American revenues approaching CAN$200 million after five years of operation.

"Acquisition was by far the most logical means of attaining that objective," he said. He noted the importance of developing a diversified line of products including aggregates as part of an acquisition strategy.

"Consolidation has advanced significantly in industrial minerals and lagged far behind in aggregates," Singelton said. "The top six lime producers in North America control approximately 60% of capacity. But the six largest aggregate producing groups in North America control less than 20% of an estimated 9,000 producing operations. That implies, with a good deal of certainty, that there are many individual producers and groups of two to three quarries making up the rest of the industry.

"The financial and management needs of these small groups continue to grow in order to meet cost and productivity requirements, to make changes demanded by environmental and community-related issues, and to comply with an ever-increasing number of complex regulations.

"Many smaller companies simply don't have the resources to meet this challenge. Providing these resources on a selective basis through acquisition has been our focus from the start.

"What do we look for in a company? Minerals, markets, and management-in that order. Following these guidelines has made Global Stone Corp. the fifth largest lime and limestone producer in North America with a market area ranging from Ontario down through the eastern United States and west to Oklahoma. Our acquisition planning is regionally influenced. We see ourselves as a predominantly eastern seaboard company and, at this stage, have no intention of going further west. We're pleased, incidentally, with the management of the operations we've acquired to date."

Following the Initial Public Offering and the acquisition of Global Stone (Ingersoll), Global Stone acquired eight more operations:

* Global Stone Tenn-Luttrell Company, Tennessee, October 1993;

* Global Stone Chemstone, Virginia, July 1994;

* Global Stone (UK) Ltd., England, November 1994;

* Global Stone Detroit Lime Company, Michigan, December 1994;

* Global Stone PenRoc Inc., Pennsylvania, June 1995;

* Global Stone St. Clair Inc., Oklahoma, December 1995;

* Global Stone James River, Virginia, June 1996; and

* Middletown Quarry, Virginia, August 1996.

In 1998, the company will produce approximately 1.4 millions tons of burnt lime products for industrial chemical uses and an additional 1.8 million tons of ground chemical grade limestone products for filler applications, metal producing, water treatment, and emissions and effluent treatment and control. A third product line-aggregates-will account for approximately 2 million additional tons of North American production.

The 1996 acquisition of James River Limestone provided a fourth product line-aglime, pelletized limestone, and hard limestone products for lawn and garden uses. Global Stone James River also produces limestone fillers and aggregates.

Global Stone Corp. controls over 700 million tons of high-purity limestone reserves, the majority of which are presently permitted. At the close of the FY1997 (Sept. 30), North American net revenue was CAN$150 million. By the close of the FY1998, gross revenues are expected to meet the $200 million level forecast in the 1993 public offering.

Global Stone PenRoc Inc.

Plant design and construction Global Stone Corporation

Automatic control system Gettle Inc.

Programmable Logic ControllerModel PLC-5 Allen-Bradley

Scalping screens (2)Double-deck J&H Equipment Inc.

Screens (2)Triple-deck Midwestern Inc.

Dust collection system Johnson-March Inc.

Dust collection system Micropul

Cylones (2) Susquehanna Metal Products

Baghouse Astec Equipment

Roller millsRaymond 66 in. A.B. Preheater Co.

Rotary dryer Barber-Greene