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: Method for the production of cement-bonded molded articles, particularly lightweight boards of wood fiber, wood chips or other lignocelluloses, of mineral fibers, glass fibers, plastic chips and fibers or various lightweight materials, like expanded silicates, expanded clay or expanded glass or granules of foamed plastics as a base material and portland cement as a binder, characterized in that the molded articles are produced in a heated molding duct formed of endless moving belts, for example, steel belts, using a portland cement as a binder in the molding compound which contains 1 to 30% by weight, perferably 15 to 25% by weight, of a calcium-halogen aluminate of the composition 11CaO.7Al.sub.2 O.sub.3.CaX.sub. 2 wherein X is any halogen. The cement with added calcium-halogen aluminate has such a short setting time, which is further accelerated by heating during molding, that boards may be successfully made on a continuous basis using a belt-molding machine.

Abstract: When a porous substrate such as perlite insulation board is surfaced with a foamed polymer layer formed in place from liquid components, the liquid components will often partially penetrate the surface, resulting in loss of materials and uneven foaming. A barrier coating which can prevent penetration is provided by applying to the porous substrate an aqueous mix of a thermosetting resin which cures through methylol groups, such as urea formaldehyde, with a component containing a hydroxyl group, such as starch, cereal flour, or the like. When the barrier coating is dried, a water insoluble cross-linked surface is formed which is impenetrable to foam constituents. A greater foam thickness is obtained for a given amount of foamable material and a more uniform thickness also results.

Abstract: A technique of forming electrodes for magneto-hydrodynamic generators having the composition (La.sub.1.sub.-x Y.sbsb.x ) CrO.sub.3 where Y is strontium, calcium or magnesium and having densities of as high as 97% of theoretical or even higher is provided. Electrodes of such densities offer superior mechanical and electrical properties when employed in magneto-hydrodynamic generators.

Abstract: A clamping device adapted to tighten a screen bottom onto a screen frame in a screening apparatus. The clamping device is provided with means disposed on one side of the screen frame for pneumatically tightening one side of the screen bottom to that side of the screen frame, the opposite side of the screen bottom being attached to the opposite side of the screen frame. The pneumatic tightening means is provided with a flexible inflatable hose and a compressed air source connected to the hose for inflating and deflating the hose.

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.

Abstract: Burned magnesite bricks are impregnated with an aqueous dispersion of carbon black, and then dried using hot dry air at a temperature above about 100.degree.C.

Abstract: Monolithic acoustical panels are provided including relatively coarse particles of expanded volcanic glass, such as perlite, and mineral fiber. The panel provides a highly porous structure that possesses desirable noise suppression characteristics, and comprises by weight 45 to 75% of an expanded volcanic glass of which 65-100% will pass an 8 mesh U.S. Standard screen and will be retained on a 50 mesh U.S. Standard screen; 10 to 30% of mineral fiber; 10 to 20% of nongelatinous cellulosic fiber having lengths in the range of about 0.5 to 3.5 mm.; and a total of 10 to 25% of binder and sizing agent.

Abstract: Improved periclase refractories are prepared by using an alkyd resin binder for tempering and pressing periclase grains into refractory shapes such as bricks. The pressed shapes are dried and fired. After firing, the refractory shapes are impregnated under vacuum with molten pitch and can then be used as lining in basic oxygen steelmaking furnaces. The fired refractory bricks have a greatly improved modulus of rupture at 1482.degree.C. of 3000-4000 p.s.i. The alkyd resin is generally incorporated in amounts of 2.5 to 4.5 weight percent.The green strength of the alkyd resin bonded bricks can be improved by adding a strong organic acid to the alkyd resin prior to mixing it with periclase grains. The green strength of bricks produced from such a mixture is between 30 and 40 p.s.i.

Abstract: Sintered ceramic articles having a high surface area-to-weight ratio and containing a plurality of ducts that extend through the article to permit fluid flow therethrough are prepared by forming an extrudable admixture of pulverized ceramic material. The admixture is forced through a forming zone in which initial shearing forces form the admixture into a plurality of discrete ribbons, and the discrete ribbons are flowed into the upstream ends of a plurality of spaced, longitudinally-extending members to form a web member containing a plurality of longitudinally-extending ducts as the ribbons flow together about the members.