THE MINERAL INDUSTRY OF PENNSYLVANIA 611 
 
clay-shale resources in the area. The Bureau of Mines and the Pennsylvania
Geologic Survey under a cooperative agreement began laboratory tests to determine
the properties and potential uses of samples from the six-county region.

 The Bylite Corp., Wilkes-Bane, manufactured Lelite by bloating metamorphic,
carbonaceous shale. The raw material came from the l3-mfflion-ton Prospect
bank, an accumulation resulting from nearby anthracite mining in the 1836—1986
period. The Prospect bank was the last remaining, large, uncontaminated shale
bank in the Lehigh Valley. The separation of carbonaceous shale from anthracite
by heavy media separation resulted in the recovery of about 15-weight-percent
salable anthracite. The recovered carbonaceous shale was crushed to minus
s/4-inch size before sintering on a 15-foot-wide, 50-foot-long grate. Oil-fueled
burners were used to attain a 2,8000 F ignition temperature during the first
5 feet of grate travel. About 450 tons per day of bloated shale was produced
when using a 14-inch-thick bed and a 1-foot-per-minute grate-travel rate.
Lelite, one of the oldest lightweight aggregates produced in the eastern
United States, was marketed in four basic sizes. 
 The A.P. Green Refractories Co. permanently abandoned, on January 6, 1972,
the Dimeling No. 1 day strip mine in Lawrence Township, Lawrence County.

 
 
Table 22.—Pennsylvania: Clays sold or 
used by producers, by use, in 1972 
Use Short tons 
Common brick 412,384 
Face brick 1,024,822 
Firebrick, block, and shapes 639,205 
High-alumina refractories 37,269 
Brakes, clutches, and linoleum 1,748 
Lightweight aggregate 72,500 
Mortar and cement, refractory 43,728 
Portland and other cements 273,181 
Sewer pipe 95,274 
Drain, quarry, and structural tile 33,292 
Other' 29,828 
Exports: 
   Refractories 9,486 
   Brick and glazed tile 8,834 
 Total 2,681,551 
 
 '  animal feed, flue linings, paint, pesticides and related products, refractory
grogs and crudes, rubber, and water treatment. 
 
 
 Pennsylvania manufacturers of refractories, plant locations, and products,
according to Industrial Minerals,'5 are listed in table 
23. 
 Fluorspar.—Fluorspar briquetting and pelletizing plants were operated
in 1972 by the Cometco Corp., Duquesne, and the Glen-Gerry Shale-Brick Corp.,
at Reading. 
 Gem Stones and Minerals.—A new Triassic copper occurrence of malachite
and azurite on fractures in hornfels (a sediment altered by an igneous diabase)
was reported near Rossville, York County. Channel samples representing ten
feet of section contained: 0.6% copper; 0.01 ounce of gold per ton; 0.2 ounce
of silver per ton. 
 Glass.—PPG at its new Mount Holly Springs plant in Cumberland County
started operating one float glass line in April and a second line in July.
When in full operation, the half-mile-long, 25-acre facility will have 850
employees and a $9 million annual payroll. The plant has a potential annual
production of 300 million square feet of glass for use primarily by the transporation
and construction industries. 
 Ponds were built at the plant for the air cooling of heated cooling water
before disposal of a portion by seepage into the ground and discharging the
remainder into a trout stream. PPG's operations in Pennsylvania included
a float glass plant in Meadville; fabricating plants at Creighton, Ford City,
Greensburg, and Tipton; a glass research center at Harmarsville; and satellite
laboratories at Creighton and Ford City. PPG announced on September 14 the
transfer of some insulating, reflective, and heat-strengthened glass making
operations from Creighton to Ford City. The transfer was expected to be complete
in January 1973 and result in the loss of about 50 jobs in the Creighton
area. At the Tipton fabricating plant, a multi-million-dollar expansion program
began, which will increase the plant's tempering capacity by 50%. 
 Employees of the Dearborn Glass Co. plant in Jermyn, Lackawanna County,
were recalled April 20 to ready the plant for a return to full production
following ratification April 19 of a 2-year contract with Allied Technical
Workers of America and Canada. The 70-employee plant manufactured face plates
for color television sets. 
Graphite.—Compared with 1971, the total tonnage of shipments of synthetic
powder, scrap, and other graphite products was 31.8% greater although the
value of production increased only 15.5%. Three companies collectively produced
anodes, dcc' 5Industrial Minerals. Refractories in the 
USA. No. 62, November 1972, pp. 9-27.