Abstract: An expanded mineral material suitable for use as a filler, e.g. instead of or in addition to sand or gravel in concrete mixes, is produced by dropping a stream of solid pellets into a rising stream of heated gas contained in a substantially vertical reactor space; the pellets consist essentially of a fusible mineral composition and a latent blowing agent; while falling in counter-current to the gas stream the pellets are heated progressively and expand at least to the point where they are capable to float in the gas stream and are carried in concurrent motion with the gas stream out of the reactor space. This reversal of motion of the expanding particles provides for a substantially self-regulating residence period of the particles in the expansion zone resulting in substantially improved process control and economy.

Abstract: The method of battery molding metal-reinforced panels of matrix forming materials like, for example, concrete is improved by the use, as reinforcement for each panel, of a stratiform and biplanar structure formed of two spaced coextensive metal sheets in a parallel and mutually supporting arrangement. Preferably, at least one sheet has a multiplicity of perforations as well as a multiplicity of protrusions. The reinforcements are provided with partitioning layers and stacked in the cavity of a molding box. Upon casting and setting of the concrete or the like material into the cavity compartments metal-reinforced panels are obtained in which the biplanar reinforcement extends substantially through the panel. The tiltable molding apparatus for use in battery-molding of the panels includes a molding box in combination with at least one fluid-cushion or fluid-bag capable of varying its outer shape in response to the amount of fluid within said cushion.