Abstract: Ceramic propping agents include a plastic clay, aluminosilicate network modifier, strength enhancing agent, and binder. Usable strength enhancing agents can include nepheline materials having 0.1 to 5 percent iron oxide by weight. A resin coating can be used to encapsulate particles of the ceramic propping agent. The propping agent can be produced by grinding the components to the same approximate particle size, nucleating the particles by adding water, growing the resulting spherical pellets by adding additional particles that adhere to the surface of the spherical pellets, and vitrifying the pellets to form the propping agent.

Abstract: A ceramic propping agent, in the form of a spherical pellet, and containing common mineral particulate. The desired propping agent is defined as a particulate ceramic made from raw materials which may be comprised of about: 10%-90% parts by weight of a naturally occurring mineral particulate, 30%-70% parts by weight aluminosilicate network modifier, 0.25-20% parts by weight strength enhancer, and at least one part, typically less than 10% by weight, binder. For use in oil and/or natural gas wells as a hydraulic fracturing proppant.

Abstract: A ceramic propping agent, in the form of a spherical pellet, and containing common mineral particulate. The desired propping agent is defined as a particulate ceramic made from raw materials which may be comprised of about: 10%-90% parts by weight of a naturally occurring mineral particulate, 30%-70% parts by weight aluminosilicate network modifier, 0.25-20% parts by weight strength enhancer, and at least one part, typically less than 10% by weight, binder. For use in oil and/or natural gas wells as a hydraulic fracturing proppant.

Abstract: A post turret tool holder for an engine lath has a body member rotatably mounted at the tool holder station of the lathe. This body member is provided with a plurality of peripheral faces each located extending from a diameter passing through the axis of rotation of the body member and at an acute angle opening inwardly toward the axis of rotation. In this manner, each face of the body member forming the turret can be oriented for selectively presenting a tool disposed in a socket provided in the face in proper position relative to the work holder without bringing adjacent tools into a position of possible interference with the work holder and workpiece and permitting the socket to be of sufficient depth into the body member to securely hold various tools commonly employed with engine lathes without interference with the axis of rotation of the body member.