A cementitious protective coating material including a mixture of water, one or more of silicon dioxide/sodium silica pozzolans, anhydrous or hydrous sodium or potassium metasilicate; a rheology enhancing admixture; sodium tetraborate, sodium citrate dihydrate, citric acid, or boric acid; and a micro-fiber.

The present invention relates to a modified red sludge or a modified bauxite residue and processes for producing same, and to a storage medium comprising a modified red sludge, a heat store comprising a storage medium and numerous uses of a It modified red sludge as storage medium, more particularly in a heat store system. The modified red sludge here contains the following components: haematite (Fe.sub.2O.sub.3), corundum (Al.sub.2O.sub.3), rutile (TiO.sub.2) and/or anatase (TiO.sub.2), quartz (SiO.sub.2), optionally perovskite (CaTiO.sub.3) and optionally pseudobrookite ((Fe.sup.3+, Fe2+).sub.2(Ti, Fe.sup.3+)O.sub.5) and/or nepheline ((Na,K)[AlSiO.sub.4]). A novel material is thus provided, and production thereof is described for use as storage medium in a sensitive energy storage system in the low-, medium- or high-temperature sector.

The present invention relates to a modified red sludge or a modified bauxite residue and processes for producing same, and to a storage medium comprising a modified red sludge, a heat store comprising a storage medium and numerous uses of a It modified red sludge as storage medium, more particularly in a heat store system. The modified red sludge here contains the following components: haematite (Fe.sub.2O.sub.3), corundum (Al.sub.2O.sub.3), rutile (TiO.sub.2) and/or anatase (TiO.sub.2), quartz (SiO.sub.2), optionally perovskite (CaTiO.sub.3) and optionally pseudobrookite ((Fe.sup.3+, Fe2+).sub.2(Ti, Fe.sup.3+)O.sub.5) and/or nepheline ((Na,K)[AlSiO.sub.4]). A novel material is thus provided, and production thereof is described for use as storage medium in a sensitive energy storage system in the low-, medium- or high-temperature sector.

The invention relates to a composition which contains modified chromate-deficient red mud, comprising a mineral composition of10 to 50 wt. % of iron compounds,12 to 35 wt. % of aluminum compounds,5 to 17 wt. % of silicon compounds,2 to 10 wt. % of titanium dioxide,0.5 to 6 wt. % of calcium compounds,0 to 1 ppm of chromium (VI) compounds, andoptionally additional unavoidable impurities. The composition, in particular the modified chromate-deficient red mud, contains a poorly soluble reducing agent for Cr(VI). In this manner, an inexpensive chemical composition is provided in particular as an iteratively functioning long-term adsorbent for pollutants in liquid, gaseous, and solid milieu. The invention further relates to a method for producing same and to uses thereof.

The invention relates to a composition which contains modified chromate-deficient red mud, comprising a mineral composition of10 to 50 wt. % of iron compounds,12 to 35 wt. % of aluminum compounds,5 to 17 wt. % of silicon compounds,2 to 10 wt. % of titanium dioxide,0.5 to 6 wt. % of calcium compounds,0 to 1 ppm of chromium (VI) compounds, andoptionally additional unavoidable impurities. The composition, in particular the modified chromate-deficient red mud, contains a poorly soluble reducing agent for Cr(VI). In this manner, an inexpensive chemical composition is provided in particular as an iteratively functioning long-term adsorbent for pollutants in liquid, gaseous, and solid milieu. The invention further relates to a method for producing same and to uses thereof.

The present invention discloses a method for synergistic stabilization/solidification of red mud and phosphogypsum. The method includes: grinding and mixing red mud and phosphogypsum, adding deionized water, uniformly stirring the mixture to prepare slurry, adjusting a pH value of the slurry to 7.5-8.5, adding a conditioner and conducting stirring, adding a stabilizer and an anti-permeability agent, uniformly stirring the mixture to obtain a gel product, and conducting solidification for 12-24 h to solidify the red mud and phosphogypsum, to obtain a red mud-phosphogypsum solidified material. In the present invention, the neutralization reaction between acidic ions in phosphogypsum and basic ions in red mud is adopted to reduce a pH value of the red mud and a transfer capability of pollutants in waste residues; synergistic solidification processing is conducted on two types of solid wastes: red mud produced in the aluminum smelting industry and phosphogypsum produced in the phosphorus chemical industry.

The present invention discloses a method for synergistic stabilization/solidification of red mud and phosphogypsum. The method includes: grinding and mixing red mud and phosphogypsum, adding deionized water, uniformly stirring the mixture to prepare slurry, adjusting a pH value of the slurry to 7.5-8.5, adding a conditioner and conducting stirring, adding a stabilizer and an anti-permeability agent, uniformly stirring the mixture to obtain a gel product, and conducting solidification for 12-24 h to solidify the red mud and phosphogypsum, to obtain a red mud-phosphogypsum solidified material. In the present invention, the neutralization reaction between acidic ions in phosphogypsum and basic ions in red mud is adopted to reduce a pH value of the red mud and a transfer capability of pollutants in waste residues; synergistic solidification processing is conducted on two types of solid wastes: red mud produced in the aluminum smelting industry and phosphogypsum produced in the phosphorus chemical industry.

Disclosed herein is a method and an apparatus for producing a shaped article. The method comprises obtaining a freshly produced aluminosilicate-containing particulate waste material and, before the waste material cools to ambient temperature, mixing the waste material into a mixture, wherein the mixture comprises the aluminosilicate, a metal oxide, an alkali, a water soluble silicate and water; shaping the mixture; and curing the shaped mixture, whereby the shaped article is produced.

Disclosed herein is a method and an apparatus for producing a shaped article. The method comprises obtaining a freshly produced aluminosilicate-containing particulate waste material and, before the waste material cools to ambient temperature, mixing the waste material into a mixture, wherein the mixture comprises the aluminosilicate, a metal oxide, an alkali, a water soluble silicate and water; shaping the mixture; and curing the shaped mixture, whereby the shaped article is produced.

A method of treatment of bauxite residue resulting from a Bayer process of bauxite treatment in order to produce a solid product. The method comprises mixing a quantity of the bauxite residue (1) with a quantity of a glass material (2) to form a mixture. Then, compressing the mixture (4) to form a green body, and sintering (5) the green body. After cooling, the sintered green body thereby provides the solid product.