Abstract: Improved, low-cost filter aid materials are made from polyurethane and related polymers. A foam of the polymeric material is comminuted to eliminate substantially all closed cells. The resulting particles are graded to a desired average particle size.

Abstract: A method is provided for treating diatomaceous earth filteraids having a beer-soluble iron content of less than about 0.01% to further reduce the beer-soluble iron content by maintaining the filteraids in contact with a relatively small volume of an acid. In the filteraids so produced, the beer-soluble iron content can be reduced by as much as 70% to 100%. In making the filteraids of this invention, sulfuric acid in about 0.1 to about 3.0 normal solution can be used to treat the starting filteraids.

Abstract: A method of increasing the magnesia content in dolomite sinter produced from dolomite. Crushed dolomite is calcined to form a physical mixture of particulate magnesium oxide (MgO) and calcium oxide (CaO) and the mixture is hydrated to develop a size differential between the calcium hydroxide and the magnesium hydroxide. The hydroxides are dried without dehydration and separated into two component portions on the basis of size. One portion of the mixture is rich in Ca(OH).sub.2 and the other is rich in Mg(OH).sub.2. The portion of the mixture primarily comprised of Mg(OH).sub.2 is then calcined to form the synthetic sinter.

Abstract: A splicing strip is provided comprising a pair of mastic layers and a porous, flexible reinforcing sheet with the mastic layers in adherent contact through openings in the reinforcing sheet. A release sheet is attached to at least the outside face of one of the mastic layers, and a sheet of non-tacky material is attached to the outside face of the other of the mastic layers.

Abstract: A furnace for firing refractory ware including a vertically movable bell adapted to enclose a car of refractory ware. Means is provided to seal the enclosure defined by the bell, to evacuate air from the sealed bell enclosure, and to deliver a fluidized, chemically inert, non-combustible, high thermal absorption material to the evacuated bell. A plurality of lasers are provided on the bell facing spaced locations therein and are adapted to be fired sequentially. When fired, the light and heat energy from each laser beam is diffused and absorbed by the inert material and is then re-radiated throughout the bell enclosure to fire the refractory ware therein.

Abstract: A process for producing an expansion joint cover is provided for structures which comprises a substantially planar strip of flexible material with an insulating material affixed thereto, wherein the flexible planar strip has lateral portions extending beyond the insulating material with a means therein to retain mechanically a rigid reinforcing member to fixed elements of the building structure.

Abstract: A construction material in sheet form having at least two water barriers including a water-impermeable foamed intermediate layer, a mineral-based interior layer, and a prefinished, weatherable, water-impermeable non-asphaltic outer layer, with adjoining layers firmly adhered. Sheets of the construction material having a foamed intermediate layer and mitered edges exposing the foamed layers are joined by the steps of positioning the sheets with the mitered edges abutting opposite sides of the stem of a bulb-T rafter, the sheets being supported by the cross-member of the bulb-T rafter, forming a foam filler in the cavity created by the abutted mitered edges, and sealing the cavity with weatherable tape. A roof deck for use with bulb-T rafters, the roof deck constructed of the aforementioned sheets joined by the aforementioned method is also shown.

Abstract: A process is described for making shaped refractories by impregnating cold pitch-bonded shaped refractories with a liquid composition comprising hot pitch.

Abstract: A system for joining and adhering a pair of abutting panels to a rigid substrate and providing a seal against thermal and moisture transfer. The system is comprised of an elongated receptacle member with a base and a pair of spaced vertical elements extending upwardly from the base and forming a channel, to be placed under and between edges of the panels to be joined. The receptacle member is firmly attached to the rigid substrate by fastening means passed through the base. The adjacent side walls of the vertical elements include a plurality of vertically spaced, downwardly angled teeth projecting inwardly towards the center of the channel. An elongated resilient insert member includes a cap and a projection extending downwardly from said cap.

Abstract: A roofing system comprising a fire resistant rigid class A fire rated board as a substrate having bonded thereto a sheet of foamed, insulating resin and having a tough weather resistant membrane bonded to the upper surface. A ledge of substrate about 1/2 inch wide protrudes beyond the formed sheet to enable the composite to be fastened to a steel roof or the like by mechanical fasteners. The channel formed by the abutting roofing panels is filled with insulating foam and covered with a membrane strip which is attached at its edges to the membrane surface of the roofing panel.

Abstract: Apparatus for sealingly joining sheets of construction material laid with edges abutting over an underlying frame and having edges rabbeted to form a joint channel including a pad for lying in the channel, a cap permanently adhered to the pad member and having edges extending past the pad for sealingly contacting the unrabbeted sheet surfaces, a metal strip embedded in the pad, and screws for securing the metal strip to the frame to capture the rabbeted surfaces of the sheets.

Abstract: A method and apparatus for selectively comminuting particles of a frangible material for the production of filter aid, the apparatus including an air-conveying system for carrying entrained particles of varying masses, a venturi for accelerating the air stream and entrained particles, a duct for receiving the accelerated air stream and particles, and impact bars mounted in the duct for selectively fragmenting the entrained particles. The impact bars are positioned in the accelerated air stream to establish adverse pressure fields which classify the entrained particles and which provide impact surfaces to fragment particles greater than a predetermined mass, the rest of the particles being deflected around the bars by the action of the adverse pressure fields.

Abstract: To dry fragile low density materials without damage, gas assisted injection and suspension of damp powder to a low velocity stream of heated gas followed by cyclone drying assures long residence time and produces a free-flowing product.

Abstract: Unfired, refractory compositions are provided containing a refractory material of magnesia, dolomite, lime or mixtures thereof, a carbonaceous binder, and elementary carbon. The amount of elementary carbon incorporated in the composition is controlled and depends on the amount of Fe.sub.2 O.sub.3 present in the refractory material. The compositions are provided with at most 1.5% elementary carbon if the Fe.sub.2 O.sub.3 content is below 0.5%; at most 1.75% elementary carbon if the Fe.sub.2 O.sub.3 content is 0.5 to 2.5%, at most 2.0% elementary carbon if the Fe.sub.2 O.sub.3 content is above 2.5 to 4.5%, and at most 2.5% elementary carbon if the Fe.sub.2 O.sub.3 content is above 4.5%. Refractory shapes and bricks produced from these refractory compositions where the amount of elementary carbon is controlled according to the Fe.sub.2 O.sub.

Abstract: This invention provides improved high fired direct bonded basic magnesite-chrome refractory shapes, such as brick, characterized by the presence of chromium enriched spinel structures distributed in the matrix and bonding the individual periclase crystals. The shapes are thermally stable and resistant to slag penetration and erosion and enjoy improved service life in industrial furnace linings. Also provided is a method of making the improved refractory shapes which comprises forming a mixture of (1) from about 40% to about 75% by weight high purity magnesite, (2) from about 25% to about 60% by weight chrome ore and (3) from about 0.5% to about 10% by weight chromic oxide powder; pressing the mixture into a refractory shape; and firing the refractory shape to a temperature of at least 1700.degree. C.

Abstract: This invention relates to the manufacture of lime-silica bonded structural materials particularly suitable where structural materials having thermal insulation properties are desired. More specifically, the invention relates to new and improved methods of manufacturing lime-silica bonded structural materials having high modulus of rupture and high compressive strength.

Abstract: The invention provides a hollow mill cutting tool capable of forming a cylindrical pin on one face of a plate member by removing material from the plate member. The cutting tool comprises a generally cylindrical member terminating in a tip portion having a toroidal cross-section and having its axis aligned with the cylindrical member. The inside diameter of the protruding end of the tip portion is selected to be the desired diameter of the cylindrical pin. The tip portion includes a plurality of forward helical surfaces each terminating at a forward end in a cutting edge extending across the thickness of the toroidal cross-section. Each helical surface extends rearwardly along a cylindrical path from the cutting edge at an angle of about 8.degree.-11.degree. with a plane transverse of the axis of the cylindrical member. A back helical surface, which is inclined at an angle of at least 55.degree. to a plane parallel to the axis, is connected to each of the foward helical surfaces.

Abstract: A binder composition comprising pitch, an aqueous solution of a water soluble resin, and an organic solvent solution of a thermosetting polymer. The binding composition in combination with particulate refractory aggregate forms a molding composition suitable for use in making shaped refractory articles. Shaped refractory articles prepared from such a molding composition are particularly suitable for use as linings in basic oxygen process steel refining vessels. Shaped refractory articles may be prepared by coating coarse refractory aggregate with the organic solvent solution of a thermosetting polymer, admixing powdered pitch with the coated coarse refractory aggregate, blending fine refractory aggregate and the aqueous solution of the water soluble resin with the coated refractory aggregate-pitch mixture, and forming the resultant composition into shaped refractory articles.

Abstract: A method is provided for the production of magnesium oxide -- chromic oxide wherein magnesium chromite of about 3 to 82 weight percent Cr.sub.2 O.sub.3 is mixed with 0.05 to 4 weight percent of CaO or SrO and sintering the mixture at a temperature above about 1750.degree. C.

Abstract: An improved process of forming sintered magnesia bodies from a magnesium hydroxide aqueous slurry wherein the slurry is dried to a moisture content where the solids can be compacted to self-supporting bodies, preferably about 5 to 8% moisture, by heating at a temperature below the dissociation temperature of the magnesium hydroxide, compacting the dried magnesium hydroxide into briquettes, heating the briquettes at a temperature above the dissociation temperature of magnesium hydroxide to form magnesia, re-compacting to form new briquettes of greater density, and heating to sintering temperature to sinter the briquettes.