Abstract: The vitreous carbon disclosed herein is prepared from intimate uniform mixtures of powder or otherwise blendable form of 20-80% by weight of a solid phenolic-aldehyde Novolak resin and of 20-80% by weight of a solid phenolic-aldehyde resol resin, the percentages being based on the combined weight of the Novolak and resol resins, and the aldehyde in said Novolak resin comprising at least 50 molar percent, preferably substantially 100 percent, furfuraldehyde, together with a carbonaceous filler, preferably graphite, in a proportion as high as 76% by weight based on the total composition. Generally the graphite may comprise 30-70%, advantageously 35-65% and preferably 40-60% of the molding composition. The vitreous carbon is improved in electrical properties and in the capability of being shaped into large thin plates which are much more stress-free than otherwise produced.

Abstract: A rubberized asphaltic concrete composition in which the particle sizes of the rubber granulate and the mineral aggregate are adjusted so that a relatively typical particle distribution is achieved in the total aggregate.

Abstract: Calcium silicate is formed by a process wherein the viscosity of the calcium silicate produced in an autoclave is lowered by adding an acetate to the reaction constituents prior to the reaction of these constituents to form the calcium silicate crystals. In one embodiment, manganese acetate is added to comprise between approximately 1% and 3% by weight of the solids contents of the reaction constituents. The result is to lower the viscosity of the reaction product and thus to allow a higher solids content in the autoclave than heretofore commonly used. In one embodiment, water is added in-line to the reaction products as they are transferred from the autoclave to a holding vessel or from a holding vessel to a storage tank. In a further embodiment, fibrous material is added to the holding vessel prior to the transfer of the reaction product into the holding vessel, thus to reduce the amount of energy required to bring the pressure in the holding vessel up to a selected pressure beneath that of the autoclave.

Abstract: An artificial diamond single crystal, a process for producing it, and tools for utilizing it are disclosed. The artificial diamond crystal has at least one surface which has a rough surface formed by suppressed crystal growth at that surface. The single crystal is produced by providing a diamond synthesis reaction system comprised of a reaction chamber, a carbon source and a solvent metal arranged in contact with the carbon source. A seed crystal is provided in the reaction chamber under elevated pressures and temperatures which permit diamond to be maintained thermodynamically stable. The reaction system is heated to provide a temperature gradient in such a way that a portion of the solvent metal in contact with the carbon source is higher in temperature than a portion of the solvent metal in contact with the seed crystal. This temperature gradient causes a migration of the carbon from the higher temperature portion to the lower temperature portion using the solvent metal as a medium.

Abstract: A method for producing carbon fibers in a vertical carbonizing furnace and an apparatus for producing carbon fibers using such a method are disclosed. The furnace includes a heating chamber for carbonizing fibers, the furnace including,(i) a fiber inlet at the upper end of the chamber(ii) an air tight sealed fiber outlet at the lower end of the furnace,(iii) an inert gas inlet provided on the wall of the chamber and above the fiber outlet,(iv) at least one inert gas injection portion, formed on the wall of the chamber, each capable of forming a curtain of inert gas across the heating chamber, each injection portion being provided between the gas inlet and the fiber inlet,(v) at least one outlet each being provided below each inert gas injection portion, and(vi) a heating member capable of controlling the temperature in the heating chamber in such a manner that the temperature gradually increases from the upper end toward a lower end of the heating chamber.

Abstract: An improved process is disclosed for the high pressure plasma hydrogenation of silicon tetrachloride. Hydrogen and silicon tetrachloride are reacted in the presence of a high pressure plasma and further in the presence of a boron catalyst to form trichlorosilane and dichlorosilane. By adding the boron catalyst the overall conversion efficiency is increased and the dichlorosilane content in the reaction effluent is increased.

Abstract: A process for treating sand which includes one or more stages in which sand is mixed with a dilute aqueous solution of hydrofluoric or sulphuric acid together with zinc or sodium hydrosulphite and the resulting slurry is agitated at ambient temperature in an atmospheric oxygen-free environment.

Abstract: A continuous process for the production of chlorine dioxide by the electrolysis of an aqueous solution of sodium chlorite is provided. The process comprises electrolyzing the aqueous sodium chlorite solution to produce chlorine dioxide which dissolves to produce an aqueous solution of NaClO.sub.2 containing chlorine dioxide. The aqueous solution of sodium chlorite-containing ClO.sub.2 is passed through a photometric cell to measure the chlorite ion concentration as a function of the color produced by the ClO.sub.2 -NaClO.sub.2 -H.sub.2 O system. Chlorine dioxide gas is removed from the aqueous solution and recovered.The novel process of the present invention employs solutions containing low, accurately controlled concentrations of sodium chlorite ion which when electrolyzed avoid the formation of by-products such as a dark colored chlorine dioxide complex and sodium chlorate.

Abstract: A floor topping, mortar and grout which include ferrosilicon in particle form. The ferrosilicon increases the wear resistance and impact strength of the topping, mortar or grout without the oxidation or discoloration normally attributable to materials which include iron borings. In addition, the ferrosilicon increases the light reflectivity of the topping material.A method of hardening and rendering wear resistant a concrete structure such as a floor comprising the placement of a mixture of Portland cement and particles of ferrosilicon material at the surface of the structure and thereafter troweling the mixture to a smooth surface.

Abstract: Pure silicon metal is produced from a silicon metal which contains 1-10% Ca and which is cast into molds with relatively slow rate of cooling. The cast metal is pre-crushed and thereupon subjected to a purification process consisting of two leaching steps where in the first leaching step there is employed an aqueous solution of FeCl.sub.3 or FeCl.sub.3 +HCl which causes a disintegration of the metal. The fines are washed away in place thereof, and the metal is further leached in the second leaching step with an aqueous HF+HNO.sub.3 solution. The necessary amount of calcium is supplied in the smelting furnace in the form of CaO or other suitable Ca compound.

Abstract: Elemental silicon is produced by a process and apparatus wherein relatively impure silane (SiH.sub.4) is purified in the gaseous state, while mixed with an inert carrier gas, to a content of electronically active impurities which is no higher than that of "electronic grade" silicon. The silane so purified is then thermally decomposed to form elemental silicon of electronic grade purity, without need for further purification of the elemental silicon itself. The silane purification is carried out by injecting the impure silane gas as a series of timed, spaced pulses into a carrier gas stream which transports the silane pulses to a gas chromatographic column, through which the pulses flow in sequence. The column has a porous polymer or a molecular sieve packing which is specially preconditioned to achieve high resolution separation of the components of the feed.

Abstract: A process for the manufacture of molded carbon bodies directly from high-boiling aromatic hydrocarbon fractions derived from coal or mineral oil, without additional binding agents and without using high pressures, is disclosed. Molds are filled with the starting material, distillation residues from the working-up of coal tar or pyrolysis products, these residues having a softening point (KS) in excess of 40.degree. C. and a quinoline-insoluble content (QI)<1.0%, and being in the liquid state, or in the solid state, and are heated, in the first step up to 550.degree. C., the residues being converted into "green" coke. In the second step, the coke is heated up to at least 800.degree. C. at a heating rate, depending on the diameter d (m), of 1.2.times.1/d.sup.2 K/day. The molded bodies can be impregnated and graphitized. They are distinguished by high electrical conductivity, low thermal expansion, and high strength in the axial direction.

Abstract: A composition for an optically anisotropic carbonaceous pitch suitable for the production of a carbon material having a high tensile strength and a high modulus of elasticity. The composition comprises about 2 to 20 percent by weight of a first, n-heptane-soluble component, about 15 to 45 percent by weight of an n-heptane-insoluble and benzene-soluble, second component and the balance of the composition including benzene-insoluble components. The composition has a volume ratio of an optically anisotropic phase of at least about 90% and a softening point of up to about 320.degree. C.

Abstract: A long shelf life cementitious anchoring capsule having a separate compartment with interactive base and catalyst components. The base component comprises cement and water, and the catalyst component comprises a catalyst and water. The base component also includes cement particles coated with a water insoluble coating and an additive to complex any calcium ion released from the cement into solution. The catalyst component also includes a material which will interact with the insoluble coating to release cement particles to allow self-setting to take place.

Abstract: Crystals of dibasic calcium hypochlorite are produced by reacting lime with a solution containing hypochlorite ions under conditions suitable to produce large crystals of dibasic calcium hypochlorite, a mother liquor and fine insoluble impurities and separating the large dibasic calcium hypochlorite crystals from the mother liquor and insoluble impurities.

Abstract: Process for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF.sub.4, by an alkali metal (liquid Na preferred) is carried out essentialy continuously by injecting of reactants in substantially stoichiometric proportions into a reaction chamber having a controlled temperature thereby to form a mist or dispersion of reactants. The reactants being supplied at such a rate and temperature that the reaction takes place far enough away from the entry region to avoid plugging of reactants at the entry region, the reaction is completed and whereby essentially all reaction product solidifies and forms a free flowing powder before reaction product hits a reaction chamber wall. Thus, the reaction product does not adhere to the reaction chamber wall or pick up impurities therefrom. Separation of reaction products is easily carried out by either a leach or melt separation process.

Abstract: A process for producing an ultrafine silicon carbide powder by passing a granulated blend of silica powder, carbon powder and a carbonaceous binder downwardly through a vertical indirect heating reactor, wherein means are provided for increasing the bulk density of the carbon powder for preventing the disintegration of the blend during the reaction which might result from the use of ultrafine powder as the carbon powder in the blend.

Abstract: A novel process is provided for the formation of improved carbonized fibrous materials with increased modulus of elasticity and strength as well as decreased diameter. Preferably, the precursor material is acrylonitrile, typically copolymerized with a minor amount of an acrylic monomer such as methyl acrylate. Drawing of the polymer fiber during oxidation is effected at an elevated temperature in the presence of a carboxylic acid (other than formic acid), or its anhydride, within the fiber. It is believed that the acid and/or its anhydride which is formed at the oxidizing temperature serves as a plasticizer and reduces the fiber yield stress and increases fiber plasticity so that the fibers may be drawn by as much as 300% or more in the presence of the acid and/or its anhydride during oxidation, thereby providing the desired improvement in increased modulus of elasticity and tensile strength of carbon fibers formed subsequently by carbonization of the oxidized fibers.

Abstract: A process for the removal of carbon- and iron-containing impurities from icon fragments which result when polycrystalline formed silicon bodies produced by vapor phase deposition undergo a crushing treatment. The removal is effected by several steps comprising nitrate treatment, annealing, acid and magnetic treatment, leaving the treated fragments in a state of highest purity that makes them particularly useful in the crucible-pulling process of Czochralski.

Abstract: A method for producing crystals of materials is described. The method comprises providing a pressure-resistant body having a nucleus of a starting material being crystallized in the inside thereof. The nucleus is applied with an energy which is capable of passing through the pressure-resistant body and being absorbed by the starting material, by which the nucleus is heated and melts. The melt is then gradually cooled under pressure to form crystals of the material. A laser beam or high frequency induction heating technique is used for heating the nucleus.