A ceramsite produced by using a river/lake/sea sludge and seashell powder as raw materials and a preparation method thereof are provided. The ceramsite is made of the following raw materials in parts by weight: 15-50 parts of shell powder, 5-15 parts of kaolin, 1-5 parts of peat ash, 15-30 parts of siliceous shale, 15-40 parts of furnace slag, 10-20 parts of fly ash, 15-40 parts of zeolite, 10-30 parts of river/lake/sea sludge, and 10-25 parts of peat. The shell powder is pulverized to a particle size of 60-200 mesh in fineness. A content of silica in the siliceous shale is 87.0%-89.5%. The preparation method of the ceramsite includes the following steps: taking raw materials, pulverizing, stirring, granulating, calcining, and naturally cooling, so as to obtain the ceramsite.

A ceramsite produced by using a river/lake/sea sludge and seashell powder as raw materials and a preparation method thereof are provided. The ceramsite is made of the following raw materials in parts by weight: 15-50 parts of shell powder, 5-15 parts of kaolin, 1-5 parts of peat ash, 15-30 parts of siliceous shale, 15-40 parts of furnace slag, 10-20 parts of fly ash, 15-40 parts of zeolite, 10-30 parts of river/lake/sea sludge, and 10-25 parts of peat. The shell powder is pulverized to a particle size of 60-200 mesh in fineness. A content of silica in the siliceous shale is 87.0%-89.5%. The preparation method of the ceramsite includes the following steps: taking raw materials, pulverizing, stirring, granulating, calcining, and naturally cooling, so as to obtain the ceramsite.

Provided herein are methods and compositions utilizing one or more cementitious replacement materials, one or more alkaline activating materials, and, optionally one or more bonding materials and/or one or more setting time enhancer materials. The one or more cement precursors comprises one or more of non-radioactive nuclear waste; swarf, insoluble hydroxide of carbonate salts, radioactive wastes, petroleum coke, spent solvent wastes, electroporating and other metal finishing wastes, dioxin-bearing wastes, chlorinated aliphatic hydrocarbons production, wood preserving wastes, petroleum refinery wastewater treatment sludges, multisource leachate, organic chemicals manufacturing waste, pesticide manufacturing waste, petroleum refining waste, human pharmaceuticals manufacturing waste; veterinary pharmaceuticals manufacturing waste; inorganic pigment manufacturing waste; inorganic chemicals manufacturing waste; explosives manufacturing waste; iron and/or steel production waste; primary aluminum production waste; secondary lead processing waste; ink formulation waste; coking waste; or a combination thereof. The one or more alkaline activating agents comprises potassium silicate, potassium hydroxide, sodium hydroxide, sodium silicate, calcium hydroxide, magnesium hydroxide, reactive magnesium oxide, calcium chloride, sodium carbonate, silicone dioxide, sodium aluminate, calcium sulfate, sodium sulfate, or dolomite, or a combination thereof. The system comprises a vertical impact mill.

Provided herein are methods and compositions utilizing one or more cementitious replacement materials, one or more alkaline activating materials, and, optionally one or more bonding materials and/or one or more setting time enhancer materials. The one or more cement precursors comprises one or more of non-radioactive nuclear waste; swarf, insoluble hydroxide of carbonate salts, radioactive wastes, petroleum coke, spent solvent wastes, electroporating and other metal finishing wastes, dioxin-bearing wastes, chlorinated aliphatic hydrocarbons production, wood preserving wastes, petroleum refinery wastewater treatment sludges, multisource leachate, organic chemicals manufacturing waste, pesticide manufacturing waste, petroleum refining waste, human pharmaceuticals manufacturing waste; veterinary pharmaceuticals manufacturing waste; inorganic pigment manufacturing waste; inorganic chemicals manufacturing waste; explosives manufacturing waste; iron and/or steel production waste; primary aluminum production waste; secondary lead processing waste; ink formulation waste; coking waste; or a combination thereof. The one or more alkaline activating agents comprises potassium silicate, potassium hydroxide, sodium hydroxide, sodium silicate, calcium hydroxide, magnesium hydroxide, reactive magnesium oxide, calcium chloride, sodium carbonate, silicone dioxide, sodium aluminate, calcium sulfate, sodium sulfate, or dolomite, or a combination thereof. The system comprises a vertical impact mill.

Provided herein are methods and compositions utilizing one or more cementitious replacement materials, one or more alkaline activating materials, and, optionally one or more bonding materials and/or one or more setting time enhancer materials. The one or more cement precursors comprises one or more of calcareous sludge; paper pulp, biomass flyash; bag house dust; biomass sludge; filter cakes from bio industry's and wastewater treatment; bio ash; biomedical ash; agricultural ash; sugar cane bagasse; rice husk ash; palm oil fuel ash; oxygen furnace slags; plant stalks; bio char; starch; pyrophyllite; or a combination thereof. The one or more alkaline activating agents comprises potassium silicate, potassium hydroxide, sodium hydroxide, sodium silicate, calcium hydroxide, magnesium hydroxide, reactive magnesium oxide, calcium chloride, sodium carbonate, silicone dioxide, sodium aluminate, calcium sulfate, sodium sulfate, or dolomite, or a combination thereof. The system comprises a vertical impact mixer.

Provided herein are methods and compositions utilizing one or more cementitious replacement materials, one or more alkaline activating materials, and, optionally one or more bonding materials and/or one or more setting time enhancer materials. The one or more cement precursors comprises one or more of calcareous sludge; paper pulp, biomass flyash; bag house dust; biomass sludge; filter cakes from bio industry's and wastewater treatment; bio ash; biomedical ash; agricultural ash; sugar cane bagasse; rice husk ash; palm oil fuel ash; oxygen furnace slags; plant stalks; bio char; starch; pyrophyllite; or a combination thereof. The one or more alkaline activating agents comprises potassium silicate, potassium hydroxide, sodium hydroxide, sodium silicate, calcium hydroxide, magnesium hydroxide, reactive magnesium oxide, calcium chloride, sodium carbonate, silicone dioxide, sodium aluminate, calcium sulfate, sodium sulfate, or dolomite, or a combination thereof. The system comprises a vertical impact mixer.

A method for accelerating the strength of cement involves providing an activated fly ash processed to increase the surface area of the fly ash and reacting the activated fly ash with a polycarboxylate heteropolymer that acts as a catalyst to produce a pozzolanic cementitious material having as much as a 28% increase in strength (e.g., compressive strength). In one embodiment, the heteropolymer includes hydrophilic and hydrophobic components that assist in providing an optimal equilibrium for the formation of cementitious structures. The increase in strength permits reducing the amount of Portland cement mixed with the pozzolanic cementitious material to as little as 30% by weight, thus achieving a significant cost reduction.

A method for accelerating the strength of cement involves providing an activated fly ash processed to increase the surface area of the fly ash and reacting the activated fly ash with a polycarboxylate heteropolymer that acts as a catalyst to produce a pozzolanic cementitious material having as much as a 28% increase in strength (e.g., compressive strength). In one embodiment, the heteropolymer includes hydrophilic and hydrophobic components that assist in providing an optimal equilibrium for the formation of cementitious structures. The increase in strength permits reducing the amount of Portland cement mixed with the pozzolanic cementitious material to as little as 30% by weight, thus achieving a significant cost reduction.

A method for separating hydrated concrete paste from aggregate includes the steps of providing a feedstock comprising waste concrete with a D10?0.1 mm and a D90?100 mm, passing the feedstock, a water containing liquid and carbon dioxide into a fragmentation vessel, where the wet feedstock is subjected to electric-pulse fragmentation, withdrawing fragmented solid material from the fragmentation vessel, separating the fragmented solid material from admixed liquid phase, separating the fragmented solid material into a fine fraction with a maximum particle size of 250 ?m to provide the carbonated recycled concrete paste and a coarse fraction, recycling the coarse fraction into the fragmentation vessel and/or discharging the coarse fraction as clean aggregate, use of the recycled concrete paste obtained thereby as supplementary cementitious material or filler.

A method for separating hydrated concrete paste from aggregate includes the steps of providing a feedstock comprising waste concrete with a D10?0.1 mm and a D90?100 mm, passing the feedstock, a water containing liquid and carbon dioxide into a fragmentation vessel, where the wet feedstock is subjected to electric-pulse fragmentation, withdrawing fragmented solid material from the fragmentation vessel, separating the fragmented solid material from admixed liquid phase, separating the fragmented solid material into a fine fraction with a maximum particle size of 250 ?m to provide the carbonated recycled concrete paste and a coarse fraction, recycling the coarse fraction into the fragmentation vessel and/or discharging the coarse fraction as clean aggregate, use of the recycled concrete paste obtained thereby as supplementary cementitious material or filler.