Abstract: A treatment method for stabilizing a sodic fly ash to reduce their leachability which is provided by a combustion process when a sodium-based sorbent comes in contact with a flue gas generated by combustion to remove at least a portion of pollutants contained in the flue gas. The treatment method comprises contacting the sodic fly ash with at least one additive comprising calcium. The material obtained from the contacting step is preferably dried. The material may be selected from the group consisting of lime kiln, dust, fine limestone, quicklime, hydrated lime, dolomitic lime, dolomite, selectively calcined dolomite, hydrated dolomite, and any mixture of two or more thereof. A particularly preferred additive comprises lime kiln dust.

Abstract: A treatment method for coal fly ash, and in particular sodic fly ash, comprises 1) contacting the coal fly ash with anhydrite, and 2) contacting the coal fly ash in the presence of water with at least one additive. The material obtained from the contacting steps (1) and (2) may be dried. The steps (1) and (2) may be carried simultaneously or sequentially. The additive may comprise at least one component selected from the group consisting of strontium-containing compounds, barium-containing compounds, dolomite, a dolomite derivative such as calcined or hydrated dolomite, water-soluble sources of silicate such as sodium or potassium silicate, iron-containing compounds, and any combinations thereof. A particularly preferred additive comprises sodium silicate. The method may be effective in reducing the sodium content in the fly ash (Na2O), reducing the alkalinity of the fly ash, and/or stabilizing at least one heavy metal such as selenium and/or arsenic to reduce their leachability.

Abstract: A treatment method for stabilizing at least a portion of at least one heavy metal contained in a sodic fly ash to reduce leachability, wherein the sodic fly ash is provided by a process whereby a sodium-based sorbent is injected in a combustion flue gas to remove pollutants therefrom. The treatment method comprises contacting the sodic fly ash with at least one water-soluble source of silicate and at least one additive comprising calcium and/or magnesium. The material obtained from the contacting step is preferably dried. The additive may be selected from the group consisting of lime kiln dust, fine limestone, quicklime, hydrated lime, dolomitic lime, dolomite, selectively calcined dolomite, hydrated dolomite, magnesium hydroxide, magnesium carbonate, magnesium oxide, and any mixture thereof. A particularly preferred additive comprises lime kiln dust and/or dolomitic lime. The heavy metal to be stabilized in the sodic fly ash may comprise selenium and/or arsenic.

Abstract: A treatment method for stabilizing a sodic fly ash to reduce their leachability which is provided by a combustion process when a sodium-based sorbent comes in contact with a flue gas generated by combustion to remove at least a portion of pollutants contained in the flue gas. The treatment method comprises contacting the sodic fly ash with at least one additive comprising calcium. The material obtained from the contacting step is preferably dried. The material may be selected from the group consisting of lime kiln, dust, fine limestone, quicklime, hydrated lime, dolomitic lime, dolomite, selectively calcined dolomite, hydrated dolomite, and any mixture of two or more thereof. A particularly preferred additive comprises lime kiln dust.

Abstract: A treatment method for reducing the leachability of selenium contained in a sodic fly ash which is provided by a combustion process when a sodium-based sorbent comes in contact with a flue gas generated by combustion to remove at least a portion of pollutants contained in the flue gas. The method comprises: (a) contacting the sodic fly ash with at least one additive in the presence of water; and (b) drying the material (preferably a paste) from step (a) to form a dried matter. The additive may comprise at least one strontium-containing compound, at least one barium-containing compound, dolomite, a dolomite derivative such as calcined or hydrated dolomite, at least one silicate-containing compound, or any combinations of two or more thereof. A particularly suitable additive may comprise strontium chloride, strontium hydroxide, pulverized dolomitic lime, sodium silicate, or any combinations of two or more thereof.

Abstract: A method is provided for reducing the abrasiveness of calcined clay, e.g., kaolin clay. The method comprises intermixing the clay prior to calcination with a finely-divided silica, preferably in the form of colloidal or fumed silica, in an amount sufficient to reduce the abrasiveness of the calcined product.

Abstract: A particulate kaolin pigment which enhances gloss and printability properties when used as a coating pigment for paper and enhances light scattering and opacifying properties when incorporated as a filler in paper, is obtained by mixing a fine particle kaolin with an aggregating agent comprising an organic silicon compound such as tetramethoxy silane or tetraethoxy silane. The feed kaolin moisture content is in the range of above 2.0 to about 5.0%, preferably 2.5 to 4.0% by weight.

Abstract: Mixed pillared clays having good thermal stabilities and high surface areas made by liquid phase methods in which an aluminum hydroxy polymer and at least one separate transition metal hydroxy polymer are prepared and mixed with a swelling clay in respective amounts to satisfy selected percentages of the cationic exchange capacity of the clay, are reduced to produce metallic transition metal domains.

Abstract: Mixed pillared clays having good thermal stabilities and high surface areas are prepared by liquid phase methods in which either (a) a discrete multi-metallic hydroxy polymer having a definite chemical formula is prepared prior to mixing with a swelling clay or (b) at least two separate metal hydroxy polymers are prepared and mixed with the swelling clay in respective amounts to satisfy selected percentages of the cationic exchange capacity of the clay.

Abstract: A structured kaolinitic pigment having improved physical and optical characteristics when incorporated as a filler in paper. The pigment is also useful in paper coating applications. The pigment consists of porous aggregates of kaolin particles which are chemically bonded together. The pigment may be produced by chemically reacting a particulate kaolin with a metal chloride, such as silicon tetrachloride. The process is conducted under conditions such that the kaolinite structure is not impaired.

Abstract: The invention relates to a structured kaolinitic pigment having improved physical and optical characteristics when incorporated as a filler or coating pigment in paper. The pigment consists of porous aggregates of kaolin particles which are chemically bonded together. The pigment may be produced by chemically reacting a particulate kaolin with a metal chloride, such as silicon tetrachloride, and with urea or an organic amine. The process is conducted under conditions such that the kaolinite structure is not altered.

Abstract: A coated paper of improved optical and printing qualities, coated with a structured kaolinitic pigment. The pigment consists of porous aggregates of kaolin particles which are chemically bonded together. The pigment may be produced by chemically reacting a particulate kaolin with a metal chloride, such as silicon tetrachloride. The process for preparing the structured pigment is conducted under conditions such that the kaolinite structure is not impaired.

Abstract: A particulate kaolin pigment which enhances gloss and printability properties when used as a coating pigment for paper and enhances light scattering and opacifying properties when incorporated as a filler in paper, is obtained by mixing a fine particle kaolin with an aggregating agent comprising an organic silicon compound such as tetramethoxy silane or tetraethoxy silane.

Abstract: A process is described in which a structured aggregated kaolin pigment is prepared by mixing substantially dry kaolin in particulate form with an aqueous alkali metal silicate to deposit on the surface of the kaolin particles a substantially molecular level of said silicate without formation of silica gel, drying the treated kaolin without calcination and exposing it to an acidic gas. The product is useful as a pigment in the coating or filling of paper.

Abstract: The invention relates to an aggregated kaolinitic pigment having improved physical and optical characteristics when incorporated as a filler or coating pigment in paper. The pigment may be produced by treating a particulate kaolin with an alkaline earth metal carbonate or hydroxide or alkali metal carbonate, and urea or an organic amine. The pigment consists of porous aggregates of kaolin particles.

Abstract: A hypergol spill, e.g., hydrazine, is safely rendered harmless by contacting it with a composition comprising cupric oxide on a porous support. Neutralization is achieved by drawing the hydrazine into the pellet pores where a reduction reaction of cupric oxide takes place. The critical consideration is to avoid flashing or spontaneous thermal decomposition of the hydrazine. Heat of reaction is quenched by the heat capacity of the pellet and water dilution.

Abstract: Delaminated trioctahedral smectite clay compositions are provided having a substantially delaminated interlayer structure with a face-to-edge and edge-to-edge association of the clay layers and an inorganic metal oxide intercalated between the clay layers. A process for preparing delaminated smectite clay compositions comprises reacting an admixture of a trioctahedral smectite clay having an average particle size up to about 500 angstroms and a polymeric cationic hydroxy metal complex in an aqueous medium and recovering the reacted clay solids.