New Galilee, Pennsylvania
Clay was an abundant resource in Beaver county. According to the 1955 circular of the Pennsylvania Geological Survey, In 1955 Beaver County produced 13.7% of Pennsylvania's total clay output. There were 13 companies that mined clay in Beaver county at that time. Two of these companies, The Negley Fire Clay Co. and Ralph A. Veon, Inc. mined fire clay of the plastic variety from open pits and marketed the output for use in manufacturing fire brick and block, foundries, and heavy clay products. In addition, Ralph A. Veon, Inc., mined and sold fire clay of the burley variety. In 1955, New Castle Refractories mined stoneware clay from an underground mine near New Galilee for use locally in manufacturing pouring channels
Sand casting
The choice of sand has a lot to do with the temperature at which the metal is poured. At the temperatures that copper and iron are poured, the clay gets inactivated by the heat, in that the montmorillonite is converted to illite, which is a non-expanding clay. Most foundries do not have the very expensive equipment to remove the burned out clay and substitute new clay, so instead, those that pour iron typically work with silica sand that is inexpensive compared to the other sands. As the clay is burned out, newly mixed sand is added and some of the old sand is discarded or recycled into other uses. Silica is the least desirable of the sands, since metamorphic grains of silica sand have a tendency to explode to form sub-micron sized particles when thermally shocked during pouring of the molds. These particles enter the air of the work area and can lead to silicosis in the workers. Iron foundries spend a considerable effort on aggressive dust collection to capture this fine silica. The sand also has the dimensional instability associated with the conversion of quartz from alpha quartz to beta quartz at 680 °C (1250 °F). Often, combustible additives such as wood flour are added to create spaces for the grains to expand without deforming the mold. Olivine, chromite, etc. are therefore used because they do not have a phase transition that causes rapid expansion of the grains, as well as offering greater density, which cools the metal faster, producing finer grain structures in the metal. Since they are not metamorphic minerals, they do not have the polycrystals found in silica, and subsequently do not form hazardous sub-micron sized particles.