Disclosed is a pottery greenware material by which a pottery having both productivity and quality can be produced with a high degree of freedom depending on an intended use thereof. The pottery greenware material includes a first greenware material and a second greenware material; both the first greenware material and the second greenware material including, as chemical species, SiO.sub.2, Al.sub.2O.sub.3, and either one or both of K.sub.2O and Na.sub.2O; and an average particle diameter (D2) of the second greenware material being smaller than an average particle diameter (D1) of the first greenware material.

Disclosed is a pottery greenware material by which a pottery having both productivity and quality can be produced with a high degree of freedom depending on an intended use thereof. The pottery greenware material includes a first greenware material and a second greenware material; both the first greenware material and the second greenware material including, as chemical species, SiO.sub.2, Al.sub.2O.sub.3, and either one or both of K.sub.2O and Na.sub.2O; and an average particle diameter (D2) of the second greenware material being smaller than an average particle diameter (D1) of the first greenware material.

A particulate mixture, suitable for use in ceramic article production, wherein the mixture includes from 30 wt % to 80 wt % recycled aluminium silicate material. The particulate mixture has a particle size distribution such that: (i) the d.sub.50 particle size is from 10 μm to 30 μm; (ii) the d.sub.70 particle size is less than 40 μm; and (iii) the d.sub.98 particle size is less than 60 μm.

A mixture for coating a metal substrate to prevent or limit scale formation. The mixture comprises 20 to 90% by weight of at least one of: an oxide ceramic material, an aluminosilicate mineral or glass frit. The mixture further comprises 1 to 20% by weight of clay and 3 to 70% by weight of an alkali metal silicate.

A recycled aluminium silicate material, suitable for use in ceramic article production, wherein the recycled aluminium silicate material has a particle size distribution such that: (i) the d.sub.50 particle size is from 10 μm to 30 μm; (ii) the d.sub.70 particle size is less than 40 μm; and (iii) the d.sub.98 particle size is less than 60 μm. A particulate mixture, suitable for use in ceramic article production, includes the above defined recycled aluminium silicate material.

A method for preparing raw kaolin (R) uses a milling and separating device (1) which has a milling section (13) and a first separating section (16). The raw kaolin (R) is a material mixture of at least kaolin as a first fraction (F1) and a second fraction (F2) which comprises at least quartz. The raw kaolin (R) is supplied to the milling section (13), in which the first fraction (F1) is at least partly removed from the raw kaolin (R) by means of a grinding process, and the first fraction (F1) is then separated from the second fraction (F2) in the first separating section (16).

Disclosed are a low-shrinkage, high-strength, and large ceramic plate and a manufacturing method thereof. The method comprises the following steps: (1) preparing a ceramic raw material powder; (2) subjecting an acicular wollastonite to surface coating with a silane coupling agent and to pre-dispersion with a fumed silica to obtain a pre-treated acicular wollastonite; and (3) thoroughly mixing the ceramic raw material powder and the pre-treated acicular wollastonite and granulating the resulting mixture, the amount of the pre-treated acicular wollastonite added being 10 wt % to 30 wt % of the ceramic raw material powder, and subjecting the resulting granules to dry pressing and sintering to obtain the large ceramic plate. The acicular wollastonite is incorporated into the manufacturing of the large ceramic plate to take full advantage of the reinforcing effect and low sintering shrinkage characteristics of the acicular wollastonite. The invention reduces sintering shrinkage and increases product strength.

A recycled aluminium silicate material, suitable for use in ceramic article production, wherein the recycled aluminium silicate material has a particle size distribution such that: (i) the d.sub.50 particle size is from 10 μm to 30 μm; (ii) the d.sub.70 particle size is less than 40 μm; and (iii) the d.sub.98 particle size is less than 60 μm. A particulate mixture, suitable for use in ceramic article production, includes the above defined recycled aluminium silicate material.

A particulate mixture, suitable for use in ceramic article production, wherein the mixture includes from 30 wt % to 80 wt % recycled aluminium silicate material. The particulate mixture has a particle size distribution such that: (i) the d.sub.50 particle size is from 10 μm to 30 μm; (ii) the d.sub.70 particle size is less than 40 μm; and (iii) the d.sub.98 particle size is less than 60 μm.

A process for the production of a ceramic article includes the steps of: (a) preparing a particulate mixture; (b) contacting the particulate mixture to water to form a humidified mixture; (c) pressing the humidified mixture to form a green article; (d) optionally, subjecting the green article to an initial drying step; (e) optionally, glazing the green article to form a glazed green article; (f) subjecting the green article to a heat treatment step to form a hot fused article; and (g) cooling the hot fused article to form a glazed ceramic article. The particulate mixture includes from 30 wt % to 80 wt % recycled aluminium silicate material. The particulate mixture has: (i) a d.sub.50 particle size from 10 μm to 30 μm; (ii) a d.sub.70 particle size of less than 40 μm; and (iii) a d.sub.98 particle size of less than 60 μm. Steps (c) and (f), and optionally steps (d) and (e) are continuous process steps.