The present invention relates to inorganic fibres having a composition comprising: 65.7 to 70.8 wt % SiO.sub.2; 27.0 to 34.2 wt % CaO; 0.10 to 2.0 wt % MgO; and optional other components providing the balance up to 100 wt %,
wherein the sum of SiO.sub.2 and CaO is greater than or equal to 97.8 wt %; and the other components, when present, comprise no more than 0.80 wt % Al.sub.2O.sub.3; and wherein the amount of MgO and other components are configured to inhibit the formation of surface crystallite grains upon heat treatment at 1100° C. for 24 hours, wherein said surface crystallite grains comprise an average crystallite size in a range of from 0.0 to 0.90 μm.

The invention relates to a refractory product, a batch for producing the product, a method for producing the product, and a use of the refractory product.

Provided are: a MnZn-based ferrite which allows to have a low magnetic core loss and to suppress a time-dependent change of magnetic property under a high-temperature environment by a control of ambient oxygen concentration and an increase of the magnetic core loss, and a method for manufacturing the same. The MnZn-based ferrite is characterized in that Fe ranges from 53.25 mol % or more to 54.00 mol % or less on the basis of Fe.sub.2O.sub.3, Zn ranges from 2.50 mol % or more to 8.50 mol % or less on the basis of ZnO and Mn is the remainder on the basis of MnO, Si ranges from more than 0.001 mass % to less than 0.02 mass % on the basis of SiO.sub.2, Ca ranges from more than 0.04 mass % to less than 0.4 mass % on the basis of CaCO.sub.3, Co is less than 0.5 mass % on the basis of Co.sub.3O.sub.4, Bi is less than 0.05 mass % on the basis of Bi.sub.2O.sub.3, Ta is less than 0.05 mass % on the basis of Ta.sub.2O.sub.5, Nb is less than 0.05 mass % on the basis of Nb.sub.2O.sub.5, Ti is less than 0.3 mass % on the basis of TiO.sub.2, and Sn is less than 0.3 mass % on the basis of SnO.sub.2, and note that the converted total amount of Ta.sub.2O.sub.5 and Nb.sub.2O.sub.5 is less than 0.05 mass % and the converted total amount of TiO.sub.2 and SnO.sub.2 is less than 0.3 mass %.

A method of making a proppant may include adding a dry ceramic precursor to a granulator, adding a slurry to the granulator, granulating the dry ceramic precursor and the slurry to form densified granules, and firing the densified granules to form a ceramic proppant. The dry ceramic precursor may include an alumina- or aluminosilicate-containing material, such as, for example, at least one of kaolin, ball clay, bauxitic kaolin, smectite clay, bauxite, gibbsite, boehmite, metakaolin, or diaspora. The slurry may include a recycled proppant material, such as, a fired recycled proppant material or a green recycled proppant material.

An NTC component comprising a first electrode (1) and a second electrode (2) is specified. The NTC component further comprises an NTC element (3) disposed between the first electrode (1) and the second electrode (2), wherein the NTC element (3) comprises a ceramic having the general composition AB.sub.2O.sub.4, and where A and B each comprise one or more of the materials Mn, Ni, Co and Cu, and B additionally comprises one or more of the materials Fe, Y, Pr, Al, In, Ga and Sb.

Provided is a zirconia sintered body that suppresses discoloration due to porcelain. The zirconia sintered body comprises at least one of a coloring agent A: erbium oxide and a coloring agent B: nickel oxide, and a composite oxide of zirconium and vanadium.

A porous material includes an aggregate in which oxide films are formed on surfaces of particle bodies, and a binding material that contains cordierite and binds the aggregate together in a state where pores are formed. The binding material or the oxide films contain a rare-earth component that excludes Ce.

Disclosed are a member for a gas sensor, a gas sensor using the member, and a method of fabricating the same. Specifically, disclosed are a member for a gas sensor using a metal oxide nanofiber material in which nanocatalysts have been uniformly bound and functionalized using chitosans with which nanoparticle catalysts have been combined, a gas sensor using the member, and a method of fabricating the same.

An armor component and manufacturing thereof which includes a ceramic hard material, where the hard material has a bulk density that is lower than 3.5 g/cm.sup.3 and includes grains of ceramic material having a Vickers hardness that is higher than 15 GPa, bonded by an bonding matrix, the bonding matrix representing between 20 and 80% by weight of the constituent hard material of the ceramic body, and including alumina, silicon nitride and TiC.sub.xN.sub.1-x crystalline phases, wherein x is included between 0 and 1.

The invention concerns a refractory ceramic batch as well as a refractory ceramic product.