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 (Na.sub.2O), 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.

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.

A method for preparing composites of polymer and fly ash particles, wherein the fly ash particles contains heterogeneous compositions of carbon and metal oxides, the method including: the steps of mixing the fly ash particles and an aqueous coating solution, including: a coating component selected from the group consisting of monomers, oligomers, pre-polymers, polymers, and combinations thereof, and an aqueous solvent serving to dissolve the coating component; and, while performing the step of mixing, initiating polymerization or cross linking or both polymerization and cross linking of the coating component to at least partially coat the fly ash particles with polymer or a crosslinked polymer network that agglomerates the fly ash particles and coats the surface of the fly ash particles, wherein the polymer or crosslinked polymer network formed in the step of initiating is hydrophobic.

A method of and an arrangement for recycling mineral wool waste to mineral wool production includes at least one melting furnace for melting virgin mineral wool raw material, the melting furnace including an inlet for virgin mineral wool raw material and an outlet for molten mineral wool material, a production line connected to the outlet for molten mineral wool material for producing a mineral wool product from the molten mineral wool material. The production line includes a curing oven, a fluidized bed reactor including an exhaust gas duct, an inlet for predetermined primary fuel, an inlet for predetermined bed material, and an outlet for an ash material, the ash material including bottom ash discharged via a bottom outlet from the fluidized bed reactor or fly ash separated by a particle separator from exhaust gas in the exhaust gas duct or a mixture of the bottom ash and the fly ash.

The present invention relates to a technology for the production of porcelain stoneware products, wherein the treatment process allows to re-use recovery materials coming from the treatment of urban waste. In particular, the present invention relates to the production of products for the construction of driveways.

A method for simultaneously drying and carbonating a mineral waste material that includes carbonatable calcium and/or magnesium compounds and/or silicate, aluminate or silicate-aluminate phases in a spray dryer, wherein a starting material slurry is provided including the mineral waste material in the form of particles with a D90500 m and at least 30 wt.-% water, a hot gas is provided including at least 4 Vol.-% CO.sub.2 and fed into the spray dryer, the starting material slurry is sprayed into the hot gas in the spray dryer wherein a temperature of 100 C. and a relative humidity of <50% are adjusted in the spray dryer, the starting material slurry is transformed into evaporated water and a dry, carbonated product comprising calcium carbonate and/or one of silica gel or alumina gel or silica-alumina gel, and the dry, carbonated product is separated from the gas and evaporated water.

The present disclosure belongs to the technical field of industrial waste solid recycling, and particularly relates to a resource comprehensive utilization process of red mud, fly ash, steel slag and coal gangue solid wastes. By using the resource comprehensive utilization process, Na.sub.2CO.sub.3, O.sub.2 and a reducing agent are added into industrial waste solids for reaction and then molten iron and liquid slag water are separated; a sodium salt is added into the liquid slag water for reaction to obtain a reaction solution and sediment; the reaction solution is successively introduced into a calcium salt precipitation tank, an aluminum salt precipitation tank and a silicic acid tank and then CO.sub.2 is introduced into the above tanks for acidification reaction, respectively, and a calcium salt, an aluminum salt, a silicic acid and an alkaline solution are obtained after filtration in sequence.

A method for recovering reusable aggregate from ash from domestic waste incineration systems is provided. Before a predeterminable maximum intermediate storage time has expired after the ash is produced, the ash is subjected to a dynamic carbonation until the remaining moisture content is less than 8.0 wt. % if the ash has a large moisture content, the dynamically carbonized ash or the ash which already has a remaining moisture content of less than 8.0 wt. % is comminuted and classified into multiple grain fractions, at least iron-containing compounds and iron oxides as well as non-iron metals are separated from each grain fraction independently of one another, and at least some of the iron-containing compounds and iron oxides and grain fractions which are free of the non-iron metals are respectively subjected to a main washing process in which the environmentally harmful pollutants adhering to the individual grains are at least partly removed.

A resource recovery method and a resource recovery system of desulfurized ash. The resource recovery method includes washing desulfurized ash with water, and performing solid-liquid separation to obtain solid residues rich in calcium sulfite and calcium sulfate and a solution rich in calcium hydroxide; preparing the solution into desulfurization slurry; and roasting the solid residues under the action of a reducing agent to obtain flue gas rich in sulfur dioxide and residues rich in calcium oxide. Therefore, the recovery of sulfur and calcium in the desulfurized ash is realized, and no solid waste, liquid waste, gas waste, etc. are produced in the process.

A refinement process to reclaim aggregates derived from municipal solid waste incineration (MSWI) bottom ash is tailored for use in the asphalt and cement industries. Initial size reduction achieves market-specific gradation to liberate fused particles, followed by magnetic separation for the recovery of ferrous and non-ferrous metals. The aggregate material undergoes density separation to remove organic contaminants and heavy metal-bearing particles across size-specific fractions. Finally, a targeted wash cycle using neutral pH water reduces the chloride concentrations of the final aggregate product. This multi-stage process produces a reclaimed aggregate with controlled absorption, loss on ignition, and contaminant levels, enabling its safe and effective use in encapsulated construction applications.