A spray material for hot and dry spray application with improved corrosion resistance, and a hot and dry spray application method with improved corrosion resistance. A hot and dry spray application method comprises pressure-feeding a mixture comprising a refractory material and a binder, toward a spraying nozzle via a pipe, and adding water to the mixture at a distal end of the spraying nozzle to apply a spray under a hot condition. The mixture contains magnesium limestone having a particle size of 0.075 mm to less than 1 mm, in an amount of 10 mass % to 50 mass %, in 100 mass % of a total amount of the refractory material and the binder. The content of magnesium limestone having a particle size of less than 0.075 mm in 100 mass % of the total amount of the refractory material and the binder is 35 mass % or less (including 0).

A coating liquid for preparing a needle-shaped cylinder liner, comprising the following components: 0.05-0.4 parts of an anionic surfactant; 0.05-0.5 parts of tannic acid; 0.15-0.7 parts of caustic soda; 22-38 parts of diatomite; 3-10 parts of montmorillonite; and 62-75 parts of water. A method for preparing a needle-shaped cylinder liner comprises spraying a coating liquid for preparing the needle-shaped cylinder liner onto the inner wall of a hollow cylindrical mould, and drying the coating liquid to obtain a mould with a coating attached to the surface of the inner wall; adding an inoculated iron liquid into the rotary mould, and cooling and demoulding to obtain a cylinder liner blank; and subjecting the blank to outer surface cleaning and forming machining to obtain the needle-shaped cylinder liner.

A corrosion-resistant ceramic of the present disclosure contains yttrium zirconium oxide as a main component and has a plurality of open pores. The difference between an average value of inter-centroid distances of the open pores and an average value of diameters of the open pores is 50 μm or greater.

The present invention relates to a composite material comprising wollastonite fibres embedded within a ceramic matrix. The wollastonite fibres are bonded to the ceramic matrix by a glassy bonding phase comprising a glass component comprising at least 80 wt % of oxides of calcium, silicon and aluminium. The material is used in the processing of molten metal, e.g. as a pump, degasser, flux injector or scrap submergence device.

A gas injection nozzle refractory with one or more gas injection small metal tubes buried therein has improved durability. The gas injection nozzle refractory includes a MgO-C central refractory with a small metal tube buried therein, and a MgO-C peripheral refractory surrounding the central refractory. The central refractory on a plane of the gas injection nozzle refractory has an external shape of a circle with a radius in the range of R+10 to R+150 mm concentric with a virtual circle with a minimum radius surrounding all buried small metal tubes, R mm being a radius of the virtual circle.

A dry substance mixture for a batch, preferably a refractory batch, for the production of a coarse ceramic, refractory, non-basic, shaped or unshaped product, such a refractory batch, such a product as well as a method for its production and a lining of an industrial furnace for the aluminum industry, and such an industrial furnace as well as a lining of a launder transport system or a mobile transport vessel for the aluminum industry, and such a launder transport system and such a transport vessel.

A refractory composition for forming a working lining in a metallurgical vessel contains a coarse-grain refractory particle fraction and a fine-grain refractory particle fraction, or at least 0.25% additive calcium oxide, or at least 0.25% titanium dioxide. The coarse-grain refractory particles can include alumina particles, magnesia particles, magnesium aluminate spinel particles, zirconia particles, or doloma particles, or a combination of any of these particles. The fine-grain refractory particles can be comprised of any low-magnesia refractory oxide. The refractory composition can be applied to a metallurgical vessel by spraying, gunning, shotcreting, vibrating, casting, troweling, or positioning preformed refractory shapes, or a combination of any of these techniques. When contacted by molten metal, the molten metal penetrates into the refractory material, wetting the coarse-grain refractory particles, and forming a refractory-metal composite barrier layer that decreases or blocks oxygen transport through the refractory lining.

A coating composition is described, for use in the foundry, in particular comprising particulate, amorphous silicon dioxide (SiO.sub.2) and an aqueous phase having a pH of at most 5, and also coated, waterglass-bound foundry molding elements, especially coated, waterglass-bound foundry molds and foundry cores, which each comprise a coating composition of the invention. Further described is the use of a coating composition of the invention for producing a coating on a waterglass-bound foundry molding element and a method for producing a waterglass-bound foundry molding element (mold or core) coated with a water-containing refractory coating. Likewise specified is a kit whose contents include a coating composition of the invention.

A single crystal ceramic core composition has an inorganic portion and an organic portion. The inorganic portion makes up about 85% by weight of the total weight of the ceramic core composition, and the organic portion makes up about 15% by weight of the total weight of the ceramic core composition. The inorganic portion includes about 94 to 98% by weight spherical fused silica, and about 2 to 6% by weight zircon flour. The organic portion includes about 84 to 88% by weight binder, about 1 to 2% by weight dye, about 6 to 12% by weight surfactant, and about 1 to 5% by weight polymeric fiber.

A metallurgical vessel structure and method is provided for producing low-impurity Magnesia-Carbon reclaimed aggregate suitable for reuse in the production of high purity Magnesia-Carbon refractory. A metallurgical vessel is assembled with a non-reactive or chemically similar backup lining. The entire height of the working lining wall is Magnesia-Carbon brick suitable for reuse. The working lining is exposed to a metal making high temperature process, and the working lining is sequentially demolished. Due to the assembly of vessel, metallurgical practice, and ease of demolishing the vessel, there is little to no need for sorting, such that the used Magnesia-Carbon brick are easily converted into low impurity Magnesia-Carbon reclaimed aggregate. A refractory composed of low-impurity Magnesia aggregate reclaimed from the method is also contemplated.