Abstract: A composition suitable for making acoustical tiles in a water-felting process comprises expanded perlite, clay, a binder component selected from the group consisting of starch, latex, cellulosic fiber and mixtures thereof and optionally mineral wool. The use of an expanded perlite having a relatively high density, preferably between about 9 pounds per cubic foot to about 20 pounds per cubic foot, enables the formation of a suitable slurry with a relatively low amount of water and enables a more complete dewatering of the mat prior to drying.

Abstract: A blend for producing refractory imitation fireplace objects comprises between 30% and 50% amorphous aluminum siliceous mineral silicate, between 1% and 5% fibre and between 40% and 60% high temperature cement. A method of producing a slurry for casting the refractory objects consists of blending the amorphous aluminum siliceous mineral silicate, the fibre, an aggregate and colorant, adding and blending a high temperature cement and a dispersant and adding between 35% and 45% by weight of water.

Abstract: A clay-free, asbestos-free and glass microbubble-free, drying type Joint compound containing an in-situ or associative thickener as a substitute for asbestos and any clay substitute therefor. In particular, these drying type joint compounds contain no attapulgus clay thereby improving viscosity stability, crack resistance and shrinkage. The lightweight joint compounds contain treated expanded perlite, treated to render it water-insensitive. The preferred in-situ thickeners are acidic acrylate copolymers. It has been found that the in-situ thickeners should be used in combination with the normal cellulosic thickeners used in joint compounds Instead of as replacements therefor. The joint compounds contain the usual fillers and latex emulsion binders, with at least about 50% by weight of the drying type joint compound being a filler selected from the group consisting of calcium carbonate and calcium sulfate dihydrate.

Abstract: A pumpable backfill grout which hardens into a controlled low strength material and an additive for making up such a backfill grout. The grout consists essentially of portland cement, a smooth surfaced vesicular expanded perlite, fly ash, fine aggregate, water, an air entraining agent, a quick dispersing thixiotropic suspending agent and a bentonite thickening agent.

Abstract: Apparatus for continuous production of intumesced, expanded, puffed, or exfoliated particles. A rotatable processing table is driven by a speed controllable motor connected to rotate the table at a desired rotational rate. Particulate feeding means overlie the table for depositing the particles to be intumesced onto a first sector in the path of the upper surface of the processing table during rotation thereof. Heating means are mounted above and below the plane of the processing table at a second sector in the rotational path of same which is spaced from the first sector, and heat expand the particles during passage through the second sector. A scraper blade is mounted above the processing table at a third sector in the rotational path of the table which is spaced and downstream from the second sector.

Abstract: A method of decreasing the expansion temperature and improving the expansion characteristics of vermiculite ore comprising subjecting vermiculite ore containing interlamellar cations to a potassium nitrate solution for a time interval sufficient to ion-exchange interlamellar cations within said ore with potassium ions. Subsequent to this ion exchange the low temperature expandable vermiculite may be expanded by heating in an oven, or incorporated in an intumescent material and heat expanded in situ, or expanded by other heating means. An intumescent sheet is provided which may be used for mounting automotive catalytic converter monoliths comprising an unexpanded vermiculite produced by the method of the invention; an inorganic fibrous material; and a binder.

Abstract: A high strength concrete particularly useful for precast, prestressed products comprising by weight of the wet concrete mix, 8 to 60 percent cement, 0.5 to 20 percent smooth-surfaced, vesicular, expanded perlite, 5 to 30 percent water, 0 to 12 percent pozzolan, and fine aggregate and coarse aggregate as appropriate and available in the circumstances. The concrete provides superior bond to reinforcing strands. The smooth-surfaced, vesicular, expanded perlite is unique and novel.

Abstract: A non-porous, substantially hollow, expanded mineral product, such as expanded perlite, is produced by uniformly and indirectly heating ore for about 1 to 30 seconds in an expansion chamber maintained at about 1400.degree. F.-2100.degree. F. to produce uncoated particles which exhibit superior short term and long term density stability characterics in liquid systems, and which may subsequently be coated to provide enhanced density stability characteristics.

Abstract: Obsidian having less than one percent of combined water is expanded to a volume many times the original by a two stage heating process carried out in at least one refractory-lined, rotary kiln. It is heated gradually by a first flame to a temperature of 1800-1900 F., then subjected to a second flame at a temperature of 2400-2500 F. for a very few minutes. The heating is carried out in the presence of dust which has a softening point considerably above those temperatures. The dust prevents the softened obsidian from sticking to itself or to the lining of the kiln. In some embodiments, the entire process is carried out in a single kiln with both flames entering the discharge end of the kiln, the first flame being directed toward the feed end and the second flame directed transversely or toward the discharge end. In another embodiment, the obsidian is gradually heated in a first kiln, then immediately fed to a second rotary kiln where the second flame enters the feed end and is directed toward the discharge end.

Abstract: Expanded perlite compositions containing thereon, therein or thereon and therein buffered aqueous silane emulsion compositions as well as hydrophobic expanded perlite compositions as described above but from which residual water has been removed are provided. A process for the preparation of the same is also provided.

Abstract: A closed gas-cell cellular material is formed by heat treating a hydrosilicate, especially perlite, at a low temperature and then in the form of grains of a grain size of 5 to 8000 micrometers, feeding these grains through a space at a temperature of 800.degree. C. to 2000.degree. C. for a short residence time at a uniform space load of 0.1 to 500 kg/h. Then the grains are subjected to thermal shock in a thermal shock space connector directly to the feed spacing and heated to 1,000.degree. C. to 3,500.degree. C. The density of the granular material thus produced is 0.12 to 27 g/cm.sup.3 and the weight per volume thereof at 0.01 to 1 kg/liter.

Abstract: Solid sorbents (acceptors) for noxious components, e.g. SO.sub.x, NO.sub.x and HX, from gases below about 250.degree., specifically acceptors that contain hydrated divalent metal oxide coated onto an exfoliated or expanded mineral support, are improved by heating them before use at a temperature of 450.degree.-650.degree. for a conditioning period of at least a few minutes. So conditioned pulverulent MgO coated onto water-laden exfoliated vermiculite (alternatively expanded perlite) is preferred because of capacity and the ability of the magnesia-based acceptors to be regenerated at a moderately elevated temperature that precludes substantial deterioration of acceptor or equipment. To insure immediate activity the conditioned acceptor is moistened for use. Advantageously the gas and/or the acceptor is humidified during their contact.

Abstract: A decorative tile having a front face with a design thereon varies in density so that the front face of the tile presents a solid appearance, but the overall weight of the tile is less than for a comparable conventional plaster tile. The tile of the invention can be made from a mixture including a binder, fiber strands, and a bulk enhancing agent. The decorative tile of this invention is particularly useful for ceiling decoration.

Abstract: A gypsum plaster and chopped glass fiber tile having increased insulation values, reduced weight and reduced density due to the presence of vermiculite and perlite.

Abstract: In the thermal process for treating swellable granulates of clay or the like, the granulates are entered in heaps (4) with free intervals between them into a shaft (1) and traverse said shaft (1) by stages from top to bottom. The heaps (4) are supported by grates (2) of which the bars may be temporarily and at least taken out from the plane of the grate (2) so that the various heaps (4) are fed in the form of a temporarily regulated trickling flow to the next stage, so that a constant thickness with respect to the cross-section is maintained. In the various stages, the heaps (4) are traversed by hot gases introduced sideways into the shaft (1) and exhausted on the other side according to a direction perpendicular to the plane of the layer.

Abstract: A process is described for the formation of shaped hydrated calcium silicate products. The process comprises reacting an aqueous slurry containing a source of calcium hydroxide, perlite as a source of silica, and a soluble calcium salt in the presence of high pressure saturated steam, then adding cooling water followed by subsequent venting of the reactor vessel to ambient pressure. Reinforcing fibers may then be added after which the desired shapes are molded and dried.

Abstract: A method and apparatus for expanding particles of a lightweight aggregate material are disclosed. The apparatus comprises a housing having an upper chamber separated from a lower chamber by a partition having a plurality of openings. Hot air is introduced into the lower chamber and flows through the partition to fluidize particles introduced into the upper chamber. Means are provided for independently regulating the velocity of air through separate sections of the partition. Particles are introduced at the inlet end of the upper chamber. The particles are fluidized and transported toward the outlet end of the upper chamber by the air flow. The temperature of the air flow causes the particles to expand and become lighter. The velocity of the air flow through separate sections of the partition is adjusted to maintain uniform fluidization of the particle bed in the upper chamber.

Abstract: Expanded perlite is produced while simultaneously or substantially simultaneously coating the expanded perlite with an hydrophobic coating material by passing the expanded perlite and heated expander exhaust gases from the expansion chamber through a cooling and coating chamber provided with spray nozzles to provide a stream of atomized coating material onto the expanded perlite, while upstream thereof an air intake and temperature sensor are situated to control the air flow and temperature in the cooling and coating chamber so as to provide proper curing temperatures for the coating material upon the expanded perlite before it is separated from the exhaust gases.

Abstract: Particulate material is heated by directing a flame downwardly along the central axis of a vertically disposed furnace. The particulate material is introduced at a number of locations distributed radially around the flame at the upper end of the furnace. The particulate material is directed downwardly and toward the central axis of the furnace placing the particulate material within the flame as it passes downwardly through the furnace.

Abstract: Mineral filler materials are provided with improved hydrophobic coatings by pressure coating of porous minerals using steam as a carrier for the coating material. Thereby more complete sealing of fissures and cracks in the porous filler materials' surface is provided, resulting in very water-resistant coated particles useful in filling polymeric substrates such as paints, plastics and joint compounds.

Abstract: Silicate-based composition particles are rapidly and completely expanded to form an expanded, cellular particulate aggregate of maximum density in short periods of time at particle temperatures which are comparatively low, that is, 100.degree. C., compared to existing systems by the utilization of infrared heat sources, either gas or electric, to heat the silicate particles. The use of infrared energy operates in a surprisingly advantageous fashion when the expansion process is carried out on or in the presence of a surface having the capacity to act as a thermal mirror or absorber-reflector of the infrared radiation to make maximum utilization of the radiant energy by the creation of a radiation trap. Carbonaceous materials are preferred for producing such entrapment. A further significant aspect is the discovery of a time-radiation dependency.

Abstract: A thermally efficient process for the expansion of perlite ore is described. The inlet port and burner of a perlite expansion chamber (preferably a vertical expander) are enclosed such that no ambient air can enter the chamber. Air and fuel are metered to the burner with the amount of air being controlled such that the fuel/air premix contains at least enough air to start and maintain minimum combustion, but not enough to provide stoichiometric combustion. At a point immediately above the burner, additional air is metered into an insulated enclosure surrounding the expansion chamber where it is preheated by the heat passing through the chamber walls. This preheated additional air is then circulated back to the burner where it provides the remainder of the air needed for combustion, normally full combustion.

Abstract: A high temperature furnace adapted to expand mineral ores such as vermiculite, perlite and the like. The furnace preferably includes an upright, vertically oriented frame adapted to support an elongated furnace tube into which mineral ore is delivered for expansion. Raw ore may be routed through a preheating system including a plurality of vertically spaced-apart, inclined baffles removably disposed within a preheating enclosure secured to the furnace. A preheater bypass system is included to facilitate use of the furnace with vermiculite. Flame control and mineral waste control are preferably effectuated with a flame guide adapted to be variably positioned intermediate a lower blast nozzle and a furnace tube heat input orifice. A plurality of thermal expansion couplings and supports are utilized to compensate for thermal expansion.

Abstract: A process and apparatus therefor are described for the expansion of perlite utilizing vaporized heavy liquid fuel as at least half, and preferably all, of the combustion fuel. In this process preheated air is used to vaporize the liquid fuel, which has previously been atomized.

Abstract: Expanded perlite is coated with polysiloxane, the coating dried, and subsequently strengthened by heating to form an attrition-resistant, non-porous, particulate filler suitable for inclusion in polymeric materials to reduce their bulk density.

Abstract: Compositions and papers made therefrom useful as separator materials in starved electrolyte lead/acid batteries are described. The compositions comprise a mixture of 30% to 80% by weight of perlite and 20% to 70% by weight of glass fibers. The glass fibers have diameters in the range of from 0.3 to 1.0 micrometers while the perlite has particle sizes in the range of from about 3 to about 100 micrometers.

Abstract: Expanded perlite is coated with polysiloxane, the coating dried, and subsequently strengthened by heating to form an attrition-resistant, non-porous, particulate filler suitable for inclusion in polymeric materials to reduce their bulk density.

Abstract: Particulate unexpanded perlite is introduced to an expansion apparatus that utilizes the combustion of a gas as a source of heat. The particulate perlite is mixed with a combustible gas, air from a first source and oxygen and thereafter introduced to a burner section. The amount of oxygen introduced is in the range of from 1.5 to 16 weight percent of the amount of air introduced. The amount of combustible gas in the mixture is related to the air input from the first source, being in the range of 1 volume of combustible gas to 2 to 6 volumes of air.

Abstract: Particulate perlite fines are agglomerated to increase the apparent particle size by forming a mixture of the perlite fines with a compound such as boric acid capable of being substantially converted to B.sub.2 O.sub.3 at elevated temperatures. The mixture is heated while mixing to convert the compound to B.sub.2 O.sub.3 and to at least partially coat the particulate perlite.The mixture is then heated above the melting point of B.sub.2 O.sub.3 to agglomerate the perlite fines. The product of this process has particular utility as an improved filter aid.

Abstract: The dust fraction of expanded perlite is bonded to the larger sized grains by spraying finely atomized paraffin at a temperature of less than 130.degree. C. upon the perlite which has been cooled to a temperature of less than 130.degree. C. In a second embodiment of the invention, the perlite is treated with a water repellent process prior to the paraffin treatment.

Abstract: Alkali resistant glass fibers and mineral wool are produced from perlite by heating perlite ores until the melt viscosity is under 15 poise and impinging a stream of the melt with a gas at from 80 to 100 psig to produce the fibers.

Abstract: Perlite reduced to a particle size of less than 200 mesh in a binder of aqueous sodium ligno-sulfonate is expanded while suspended in a gaseous medium in a fluidized state at temperatures ranging from 1800.degree. to 2200.degree.F. for a period of 30 to 60 seconds. The resultant microspheres have excellent physical properties and are suited to use as fillers for resins.