A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

A composite filter aid may include acid-washed diatomaceous earth and a low extractable metal mineral. A method for making a composite material may include blending an acid-washed diatomaceous earth and a low extractable metal mineral, adding a binder to the blended diatomaceous earth and low extractable metal mineral, and forming the composite material from the acid-washed diatomaceous earth, the low extractable metal mineral, and the binder. A method for filtering a liquid may include providing a liquid for filtering and filtering the liquid through a composite filter aid that includes an acid-washed diatomaceous earth and a low extractable metal mineral.

A composite filter aid may include diatomaceous earth, natural glass, and a precipitated silica binder, wherein the filter aid has a permeability ranging from 3 to 20 darcys. A composite filter aid may include diatomaceous earth, perlite, and a precipitated silica binder, wherein the filter aid has an alpha density less than 15 lbs/ft.sup.3. A method for making a composite material may include blending diatomaceous earth and perlite, adding alkali silicate to the blended diatomaceous earth and perlite, and precipitating the alkali silicate as a binder to make the composite material. A method for filtering a beverage may include using a composite filter aid and/or composite material.

Compacting expanded perlite fines in the presence of a clay and water, followed by drying, produces particles with low density, good integrity, and surprisingly higher absorption by volume than non-compacted expanded perlite or non-swelling clay. Furthermore, addition of a clumping agent to the compacted granules results in a clumping litter with low density, good integrity and comparable clumping ability to traditional clay clumping litter.

A method for calcining diatomaceous earth may include adding at least one lattice interfering agent to the diatomaceous earth to form a composite material. The method may further include heating the composite material at a temperature of at least about 800 C. for at least about 15 minutes to form an at least partially calcined composite material. The at least one lattice interfering agent may include at least one cation of at least one of aluminum and titanium. A diatomaceous earth product may include the at least partially calcined composite material formed from the above-noted method for calcining diatomaceous earth. A filter aid may include the diatomaceous earth product.

Disclosed is a method for recovering a spent metal-containing homogeneous catalyst using a solid adsorbent selected from bleaching agents, filter aids and mixtures thereof. In particular, the solid adsorbent is selected from bleaching earths, perlites, diatomaceous earths and mixtures thereof. Disclosed is a method for recovering a spent metal-containing homogeneous catalyst including the following steps: (A) providing a solution containing the spent metal-containing homogeneous catalyst, the solution containing at least one solvent selected from water and an organic solvent, (B) adding to the provided solution the solid adsorbent to obtain a suspension of a solid and a solvent, (C) separating the suspension to obtain a purified solvent and the solid adsorbent containing the spent metal-containing homogeneous catalyst adsorbed thereon.

Compacting expanded perlite fines in the presence of a clay and water, followed by drying, produces particles with low density, good integrity, and surprisingly higher absorption by volume than non-compacted expanded perlite or non-swelling clay. Furthermore, addition of a clumping agent to the compacted granules results in a clumping litter with low density, good integrity and comparable clumping ability to traditional clay clumping litter.

A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

A method of treating coal that is combusted in a combustion chamber at a coal-combustion facility that includes adding an additive to the coal for mercury emissions control. The adding of the additive to the coal is performed before the coal enters the combustion chamber. The additive includes Br.sub.2, I.sub.2, a bromide compound, an iodide compound, HBr, HI, or a combination thereof.

A promoted carbon and/or non-carbon base sorbent are described that are highly effective for the removal of mercury from flue gas streams. The promoted sorbent comprises a carbon and/or non-carbon base sorbent that has reacted with and contains forms of halogen and halides. Optional components may be added to increase and/or preserve reactivity and mercury capacity. These may be added directly with the base sorbent, or in-flight within a gas stream (air, flue gas, etc.), to enhance base sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The promoted sorbent can be regenerated and reused. Base sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active base sorbent into the mercury contaminated gas stream are described.