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.

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.

A porous ceramic filter having one or more coatings of elemental or compounds of iron, manganese, aluminum, titanium, or mixtures thereof deposited on the surface of the pores.

A porous ceramic filter having one or more coatings of elemental or compounds of iron, manganese, aluminum, titanium, or mixtures thereof deposited on the surface of the pores.

A method of making a sintered ceramic proppant may include providing a kaolin clay. The kaolin clay may include an Al.sub.2O.sub.3 content no greater than about 46% by weight, and a K.sub.2O content no greater than 0.1% by weight. The kaolin clay may have a particle size distribution such that greater than 70% of the particles have an equivalent spherical diameter of less than 0.5 microns as measured by Sedigraph, and a shape factor less than about 18. The method may further include blunging the kaolin clay, agglomerating the kaolin clay, and sintering the agglomerated kaolin clay to produce a sintered ceramic proppant. The kaolin clay may have an A-bob Hercules viscosity of at least about 3,300 rpm at 18 kilodyne-cm and 70% solids.

A method of making a sintered ceramic proppant may include providing a kaolin clay. The kaolin clay may include an Al.sub.2O.sub.3 content no greater than about 46% by weight, and a K.sub.2O content no greater than 0.1% by weight. The kaolin clay may have a particle size distribution such that greater than 70% of the particles have an equivalent spherical diameter of less than 0.5 microns as measured by Sedigraph, and a shape factor less than about 18. The method may further include blunging the kaolin clay, agglomerating the kaolin clay, and sintering the agglomerated kaolin clay to produce a sintered ceramic proppant. The kaolin clay may have an A-bob Hercules viscosity of at least about 3,300 rpm at 18 kilodyne-cm and 70% solids.

A process for producing a molded insulating part, a molded insulating part and a casting tool for the production of an inorganic pulp composed of water, glass fibers and/or mineral fibers and sheet silicate, introduction of the pulp into a cavity of a casting tool whose wall is at least partially water-permeable, which cavity has on at least one side the negative shape of the molded insulating part to be produced, removal of the aqueous fraction present in the pulp, opening of the casting tool and subsequent taking-out of the molded insulating part produced. The pulp produced using water for producing the molded insulating part comprised a glass fiber/sheet silicate mixture or mineral fiber/sheet silicate mixture has a proportion of exclusively synthetic sheet silicate (5) in the range from 0.5% to 2.5% and a proportion of glass fibers and/or mineral fibers (4) of from 0.3 to 1.5%.

A process for producing a molded insulating part, a molded insulating part and a casting tool for the production of an inorganic pulp composed of water, glass fibers and/or mineral fibers and sheet silicate, introduction of the pulp into a cavity of a casting tool whose wall is at least partially water-permeable, which cavity has on at least one side the negative shape of the molded insulating part to be produced, removal of the aqueous fraction present in the pulp, opening of the casting tool and subsequent taking-out of the molded insulating part produced. The pulp produced using water for producing the molded insulating part comprised a glass fiber/sheet silicate mixture or mineral fiber/sheet silicate mixture has a proportion of exclusively synthetic sheet silicate (5) in the range from 0.5% to 2.5% and a proportion of glass fibers and/or mineral fibers (4) of from 0.3 to 1.5%.

A lightweight composite having an activated surface contains a lightweight hollow core particle having cement grains which may be adhered to the hollow core or embedded in the surface of the hollow core. The hollow core particle may be prepared from calcium carbonate and a mixture of clay, such as bentonite, and a glassy inorganic material, such as glass spheres, glass beads, glass bubbles, borosilicate glass and fiberglass.

A lightweight composite having an activated surface contains a lightweight hollow core particle having cement grains which may be adhered to the hollow core or embedded in the surface of the hollow core. The hollow core particle may be prepared from calcium carbonate and a mixture of clay, such as bentonite, and a glassy inorganic material, such as glass spheres, glass beads, glass bubbles, borosilicate glass and fiberglass.