摘要:
A method of repairing an oxide-based refractory body by projecting a powder mixture against a hot surface of the body and in the presence of oxygen to provide a refractory repair mass includes providing a powder mixture composed of particles of at least one refractory oxide; fuel particles which react in an exothermic manner with the oxygen to form a refractory oxide and which are particles composed of at least one element selected from the group consisting of magnesium, aluminum, silicon, and mixtures thereof; and particles of silicon carbide present in an amount which is effective to provide a reduced porosity of the refractory repair mass and which does not exceed 10% by weight based on the weight of the powder mixture; and projecting the powder mixture against a hot surface of the oxide-based refractory body and in the presence of oxygen. Preferably, the powder mixture contains at least 1%, most preferably from 1 to 5%, by weight of the particles of silicon carbide. Preferably, the particles of silicon carbide have a particle size of less than 200 .mu.m.
摘要:
A method and powder mixture are described for cutting a refractory body. The powder mixture comprises refractory metal oxide particles and fuel particles which burn exothermically by combining with oxygen to form a refractory oxide. The mixture is characterised in that the refractory metal oxide of the powder mixture comprises calcium oxide and/or magnesium oxide. The powder mixture enables refractory bodies to be cut more effectively than hitherto.
摘要:
A process for producing a crystalline siliceous refractory mass includes providing particulate constituents to be projected comprised of (1) solid refractory particles comprising silica in the form of vitreous silica, and (2) solid combustible particles comprising silicon particles; projecting the particulate constituents with gaseous oxygen against a surface under ceramic welding conditions effective to cause a reaction between the solid combustible particles and the gaseous oxygen to occur against the surface, thereby releasing the heat of reaction against the surface so that a coherent refractory mass comprising cristobalite is formed, wherein the surface against which the solid refractory particles are projected is at a temperature of at least 1000.degree. C. The process can be used to manufacture refractory bricks or blocks, to repair furnaces, or to repair worn surfaces of a siliceous refractory material.
摘要:
A process for forming a coherent refractory mass on a surface of a refractory, which refractory includes at least one silicon compound, the process including providing a mixture including (1) combustible particles including silicon particles, (2) refractory particles of one or a plurality of substances which constitute a major portion by weight of the mixture, and (3) particles of another substance or precursor of the another substance which particles are nonmetallic and which another substance causes incorporation of silica, formed by combustion of the silicon particles, into a crystalline lattice of a compound formed between the silica and the another substance within the coherent refractory mass to be formed; and projecting the mixture against the surface of a refractory, simultaneously with oxygen, so that the combustible particles react in an exothermic manner with the projected oxygen and release sufficient heat to form the coherent refractory mass under action of heat of combustion and so that silica is formed by combustion of the silicon particles, which silica is incorporated into the crystalline lattice of the compound formed between the silica and the another substance such that the coherent refractory mass adheres durably to the surface of the refractory and retains this adherence under repeated variations in thermal conditions.
摘要:
A ceramic welding process for forming a coherent refractory mass on a surface of a refractory which is hot and which is comprised of at least one silicon compound includes providing a mixture composed of combustible particles including silicon particles, refractory particles which are silicon carbide particles and which constitute a major portion by weight of the mixture, and particles of one of (a) another substance selected from the group consisting of CaO, MgO, FeO, and mixtures thereof or (b) particles of a nonmetallic precursor of the another substance, which another substance causes incorporation of silica, formed by combustion of the silicon particles, into a crystalline lattice of a compound formed between the silica and the another substance within the coherent refractory mass being formed; and projecting the mixture against the surface of the refractory, simultaneously with substantially pure oxygen, so that the combustible particles react in an exothermic manner by combusting with the projected oxygen and release sufficient heat to form the coherent refractory mass under action of heat of combustion, and so that silica, formed by combustion of the silicon particles, is incorporated into the crystalline lattice of a compound formed between the silica and the another substance.
摘要:
A ceramic welding process for the formation of a coherent refractory repair mass on a surface of an electrocast refractory material includes providing an electrocast refractory material having a surface to be repaired; providing a first powder mixture comprised of combustible particles, refractory particles, and at least one constituent which enhances production of a vitreous phase in the coherent refractory repair mass; and projecting the first powder mixture in a gas stream containing oxygen against the surface to be repaired so that the combustible particles react with the projected oxygen against the surface in a highly exothermic manner and release sufficient heat of combustion to form a first coherent refractory repair mass.
摘要:
A process and apparatus for making a ceramic article, especially pipes and tubes of ceramic material such as silicon carbide, in which the article is formed by projecting a ceramic powder mixture comprising refractory particles and combustible particles against a smooth-surface metal former which is heated to a temperature of at least 850.degree. C. where in the presence of an oxygen-rich gas the combustible particles react exothermically to produce from the refractory particles and the reaction product of the combustible particles a coherent refractory article in the shape of the former.
摘要:
The present invention provides a method for identifying a glass defect source, whereby a glass defect source can directly be identified without using a mathematical simulation. The method for identifying a glass defect source, which comprises a step of constructing a glass melting furnace by using, as lining furnace material, a fusion cast refractory containing at least one tracer component selected from Cs2O, SrO, BaO and ZnO, a step of melting a glass material by the glass melting furnace and forming the molten glass material to produce glass products, and a step of extracting one having a glass defect from the glass products and analyzing its component composition to determine the position of a glass defect source in the glass melting furnace.
摘要:
Apparatus and process for one of flame treatment or ceramic welding, the apparatus including a single tubular lance having a tip end, a butt end, and a head portion with a central main bore provided at the tip end so that ceramic welding materials comprised of particulate material containing oxidizable particles and combustion-supporting carrier gas are introduced at the butt end, pass through the main bore and emerge at the tip end during ceramic welding; wherein the head portion further comprises at least one conduit to convey a mixture of a fuel gas and a combustion-supporting gas, each of the at least one conduit having an orifice at the tip end of the single tubular lance and being provided with a portion for introduction of fuel gas and a portion for introduction of combustion-supporting gas so that fuel gas and combustion-supporting gas introduced at the butt end combine in the at least one conduit and emerge to form a flame at the tip end of the at least one conduit during flame treatment, and wherein the head portion is formed in two parts including an inner block including the central main bore, the conduits for fuel gas and combustion-supporting gas, and respective outlet orifices of the central main bore and at least one conduit, and an outer block including supply passageways to the inner block from respective supply tubes for particulate material and combustion-supporting carrier gas and for fuel gas and combustion-supporting gas.
摘要:
A process for cleaning a surface of a refractory structure which is at an elevated temperature, including projecting against the surface a comburent gas stream which is a powder stream including fuel particles carried in an oxygen-containing carrier gas the comburent gas stream impinging upon the surface at an impingement zone, whereby the fuel particles are caused or allowed to burn in a reaction zone defined generally around the impingement zone and the heat generated by the combustion of the fuel particles causes the surface or material adhered thereto to melt and provide a melted material, and projecting a scouring stream including oxygen simultaneously or alternately at the surface to scour the surface in the vicinity of the reaction zone and thereby clean the surface due to the scouring stream blowing away the melted material.