Abstract: An apparatus and method which provides for controlled melting of both components of coal-ash, as well as the melting of selected additives, the melted coal-ash with additive being immediately available to a conventional fiberizing spinner stage. An arc furnace provides a shallow vat for molten pig iron. A first chute allows for introduction of coal-ash into the vat, and a second chute allows for the introduction of selected additives into the vat. The molten pig iron quickly melts any coal-ash and additive entering the vat, and the molten coal-ash/additive thereupon spreads out across the surface of the molten pig iron (the molten pig iron having a much higher specific gravity). In order to ensure that the molten coal-ash/additive has a predetermined fluidity at an adjacent spinner stage, the furnace is provided with a specially structured spout located above the spinner stage.

Abstract: A method for casting molten metal in a mold having integral heat exchange piping. A mold is provided around a pattern, which may be either the disposable or permanent kind. Heat exchange piping is providing by bending seamless carbon steel pipes and placing the pipes into the mold. According to the method of the present invention, during the casting step, the pipes are simultaneously held at selected locations within the mold by hangers that are affixed to the mold, and allowed to expand at their ends into expansion cavities in the mold.