Disclosed herein are methods for making a bonded refractory material, the methods comprising preparing a slurry comprising glass precursor particles having an average particle size ranging from about 1 nm to about 200 nm; combining zirconia particles with the slurry to form a batch composition comprising at least about 80% by weight of zirconia; forming a green body from the batch composition; and sintering the green body to form a sintered refractory material. Sintered high-zirconia refractory materials can comprise at least about 80% by weight of zirconia having an average grain size of 100 microns or less, wherein the zirconia is interspersed in a glassy phase, and wherein the sintered refractory materials comprise about 15% or less by weight of the glassy phase. Melting vessels having at least one interior surface comprising such sintered zirconia refractory materials are further disclosed herein.

A ceramic composition which can be used as a sintering aid includes 1-2 mol % of magnesium oxide (MgO), 5-15 mol % of aluminum oxide (Al.sub.2O.sub.3), 25-40 mol % of silicon dioxide (SiO.sub.2), 40-55 mol % of calcium oxide (CaO), 0.1-8 mol % of ferric oxide (Fe.sub.2O.sub.3), 0.1-2 mol % of sulfur trioxide (SO.sub.3) and 0.1-2 mol % of titanium oxide (TiO.sub.2). Alternatively, the ceramic composition includes 1-8 mol % of MgO, 5-15 mol % of Al.sub.2O.sub.3, 25-40 mol % of SiO.sub.2, 40-55 mol % of CaO, 0.1-8 mol % of Fe.sub.2O.sub.3, 0.1-2 mol % of SO.sub.3 and 0.9-2 mol % of TiO.sub.2.

Embodiments of the present disclosure are drawn to a wave-absorbing material that includes a main composition, an auxiliary composition, and a sintering additive. The main composition includes at least one of Fe.sub.2O.sub.3, MnO, ZnO, and MgO. The auxiliary composition includes at least one of CeO.sub.2 and P.sub.2O.sub.5. The molar ratio of CeO.sub.2 to P.sub.2O.sub.5 ranges from about 1:1 to about 2:1. A method for preparing the wave-absorbing material is also provided.

The present invention relates to a ceramic slate with a colored jade effect and a preparation method comprising: pressing and forming raw materials containing a ceramic base material and colored glass fragments to obtain a ceramic green body; drying and firing the ceramic green body to give a ceramic slate with colored jade effect particles dispersed on the surface of the green body; wherein, the colored glass fragments account for 3 wt % to 5 wt % of the ceramic base material. Since colored glass waste instead of frits and pigments is used to prepare the ceramic slate with the colored jade effect, the ceramic slate does not have the phenomenon of pigment dispersion after high-temperature firing, and the surface of the fired ceramic slate shows a shape of micro-protrusion, so that the polished tile surface is smoother and free from pits, resulting in a better tile surface effect.

Disclosed is a CBS-based low-temperature co-fired ceramic (LTCC) material, and a preparation method thereof. The material has, as a main component, a sintered phase of low dielectric constant of CaSiO.sub.3 and CaB.sub.2O.sub.4, and comprises CBS and a dopant. The CBS comprises, by weight, 30-40% of CaO, 15-30% of B.sub.2O.sub.3, and 40-50% of SiO.sub.2, and the dopant comprises 0-2% of P.sub.2O.sub.5, 0-2% of nanometer CuO, and 0.5-2% of nanometer V.sub.2O.sub.5. The preparation method comprises mixing oxides including a CBS-based dielectric ceramic as a base and one or two of P.sub.2O.sub.5 and CuO as an initial dopant, and then adding V.sub.2O.sub.5 as a final sintering aid, to prepare the material. In the present invention, a CBS-based LTCC material that is obtained by sintering at a low temperature and has the advantages of low dielectric constant, low loss, and good overall performance is provided.

A first circumferential wall disposed in a circumference of partition walls has no interface with the outermost circumference partition wall in a circumferential portion constituted by the partition walls whose wall thickness is larger than that of a central portion constituted by the partition walls in a central region. A maximum thickness of a total of the first circumferential wall and a second circumferential wall disposed to surround an outer side of the first circumferential wall is 1.2-3.0 mm, a difference between the maximum thickness and a minimum thickness of the total is 0.2-1.5 mm, and there is satisfied a relation, 0.5(TBTA)SB/SA100(%)9.0 in which TB and TA indicate average thicknesses (m) of the partition walls in the circumferential and central portion respectively, and SB and SA indicate areas (cm.sup.2) of the circumferential portion and the honeycomb structure in the cross section respectively.

Disclosed herein are methods for making a bonded refractory material, the methods comprising preparing a slurry comprising glass precursor particles having an average particle size ranging from about 1 nm to about 200 nm; combining zirconia particles with the slurry to form a batch composition comprising at least about 80% by weight of zirconia; forming a green body from the batch composition; and sintering the green body to form a sintered refractory material. Sintered high-zirconia refractory materials can comprise at least about 80% by weight of zirconia having an average grain size of 100 microns or less, wherein the zirconia is interspersed in a glassy phase, and wherein the sintered refractory materials comprise about 15% or less by weight of the glassy phase. Melting vessels having at least one interior surface comprising such sintered zirconia refractory materials are further disclosed herein.

A method for producing a lightweight ceramic aggregate, particularly from coal ash, according to the invention is characterized in that the raw material mixture of the total moisture content preferably below 20% by weight consisting of power station ashes originating from combusting coal, or ashes from combusting coal in a mixture with biomass ash, or ashes from co-combusting biomass with coal and phosphogypsum in an amount of up to 50% by weight, taken from dumps and/or from direct dump from a power station or a heat and power station, the raw materials from the dumps preferably being heated up in winter by a mixture of atmospheric air and exhaust gases from the step of burning and sintering, with a content of non-burnt coal above 6% by weight, agglomeration promoting agents like silty non-organic materials, preferably bentonite, preferably in an amount of up to 4% by weight, clay preferably up to 6% by weight, organic waste materials like used paints and lacquers, after-fermentation sludge in an amount preferably of up to 10% by weight, and after-coal mining waste materials in an amount preferably of up to 50% by weight, the mixture being completed with dust separated from exhaust gases produced during the step of burning and sintering, is fed to preferably at least one of two or more granulating disks, or in a cascade-type manner to at least two granulating disks, where it is sprayed with water, preferably in a form of a mist, to the total moisture content preferably below 30% by weight. Next, the screened fraction of grains of the granularity of preferably 6-30 mm, is subjected to counterflow drying in the heat of a mixture of the atmospheric air and cooled exhaust gases from the step of burning and sintering, the cooled exhaust gases having the temperature below the ignition temperature of the granulated material. The dried granulated material is subjected to burning and sintering in a co-flow rotary oven with radial air supply, with filling the oven with the granulated material preferably above 50% of its volume without adding any external fuel. Next, the burnt granulated material is subjected to a non-membrane atmospheric air cooling process in a crossed arrangement in a cooling bed, preferably of a transporter or grate type, the cold air being fed to the cooling bed into its specific cooling zone in such an amount that its mixture with the exhaust gases led out from the oven is suitable for drying the granulated material in the drier, for heating up, particularly in the winter, the raw materials taken from the dumps, and for feeding the nozzles radially delivering hot gases into the rotary oven. Finally, the granulated material cooled down preferab

A method for producing a green body includes forming a layer which contains a powder of a ceramic on a substrate, applying at least one solidifying composition on at least a part of the layer, repeating forming the layer and applying at least one solidifying composition at least one time, removing the solvent or dispersing agent at least in part for forming a green body, and removing the powder which has not bonded and thereby exposing the green body. The solidifying composition contains a dissolved or liquid organometallic compound, which has at least one atom other than C, Si, H, O, or N bonded to at least one organic moiety, an organic binding agent, and a solvent or dispersing agent.

Provided is an alumina composite ceramic composition which has electrical insulation properties as well as better mechanical strength and thermal conductivity than a typical alumina-based material. Thus, the alumina composite ceramic composition is promising for a material of a substrate or an insulating package of an electronic device. The alumina composite ceramic composition of the present invention may include alumina (Al.sub.2O.sub.3), zirconia (ZrO.sub.2) or yttria-stabilized zirconia as a first additive, and graphene oxide and carbon nanotubes, as a second additive. In this case, in consideration of two aspects of sinterability and electrical resistivity characteristics of the alumina composite ceramic composition, the graphene oxide may be appropriately adjusted to be in the form of a graphene oxide phase and a reduced graphene phase which coexist in the alumina composite ceramic composition.