A ceramic composition which can be used as a sintering aid includes 1-2 mol % of magnesium oxide (MgO), 5-15 mol % of aluminum oxide (Al.sub.2O.sub.3), 25-40 mol % of silicon dioxide (SiO.sub.2), 40-55 mol % of calcium oxide (CaO), 0.1-8 mol % of ferric oxide (Fe.sub.2O.sub.3), 0.1-2 mol % of sulfur trioxide (SO.sub.3) and 0.1-2 mol % of titanium oxide (TiO.sub.2). Alternatively, the ceramic composition includes 1-8 mol % of MgO, 5-15 mol % of Al.sub.2O.sub.3, 25-40 mol % of SiO.sub.2, 40-55 mol % of CaO, 0.1-8 mol % of Fe.sub.2O.sub.3, 0.1-2 mol % of SO.sub.3 and 0.9-2 mol % of TiO.sub.2.

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 method for recovering valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing belongs to the area of comprehensive recovery and high value utilization of metallurgical waste residue. In this method, cyanide tailings, bentonite, calcium chloride, coal powder and albite are mixed by ball milling according to certain weight ratio to get a mixture. After drying and roasting twice, dust is collected from the roasted ash, the obtained polymetallic ash is collected and treated. The secondary calcined material is cooled to obtain ceramsite. The invention volatilizes and recovers the valuable metal in the roasting and sintering process of cyanide tailings and directly prepares the ceramsite through reasonable batching, which achieves the effect of recycling cyanide tailings and high-value utilization, can create good economic and environmental benefits, and has significant effect of energy saving and consumption reduction.

A method for preparing ceramsite by using municipal sludge as raw material, including the following specific steps: drying; preparing ingredients including raw sludge, fly ash, kaolinite, steelmaking slag, zeolite, hematite, calcareous shale, waste incineration fly ash, Fe.sub.2O.sub.3, waste glass, calcium carbonate, sodium lauryl sulfate, and sodium benzoate; mixing and stirring uniformly, and putting the stirred materials into a granulating machine for granulation; drying and preheating the material pellets after granulation, and then quickly transferring to a sintering device for first sintering at a low temperature and then sintering at a high temperature; crushing large chunks of the cooled materials; and separating and screening the crushed materials. The method of the present invention reduces the generation of the large chunks of the cooled materials in the obtained ceramsite, thereby reducing the subsequent crushing work and saving energy consumption accordingly.

A method for recovering valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing belongs to the area of comprehensive recovery and high value utilization of metallurgical waste residue. In this method, cyanide tailings, bentonite, calcium chloride, coal powder and albite are mixed by ball milling according to certain weight ratio to get a mixture. After drying and roasting twice, dust is collected from the roasted ash, the obtained polymetallic ash is collected and treated. The secondary calcined material is cooled to obtain ceramsite. The invention volatilizes and recovers the valuable metal in the roasting and sintering process of cyanide tailings and directly prepares the ceramsite through reasonable batching, which achieves the effect of recycling cyanide tailings and high-value utilization, can create good economic and environmental benefits, and has significant effect of energy saving and consumption reduction.

The present invention relates to a non-spray-drying, dry-granulation process for making a ceramic particulate mixture comprising from 4 wt % to 9 wt % water, wherein at least 90 wt % of the particles have a particle size of from 80 m to 600 m, wherein the process comprises the steps of: (a) forming a precursor material; (b) subjecting the precursor material to a compaction step to form a compacted precursor material; (c) subjecting the compacted precursor material to a crushing step to form a crushed precursor material; and (d) subjecting the crushed precursor material to at least two air classification steps, wherein one air classification step removes at least a portion of the particles having a particle size of greater than 600 m from the crushed precursor material, and wherein the other air classification step removes at least a portion of the particles having a particle size of less than 80 m from the crushed precursor material.

The invention relates to a process for producing proppants, including the following steps: providing red mud, providing fly ash, producing a mixture from the red mud and the fly ash so that the mixture has a first moisture content in the range of 7 to 30 wt. %, producing a granular product from the mixture, and sintering the granular product.

There is provided synthetic proppants, and in particular polysilocarb derived ceramic proppants. There is further provided hydraulic fracturing treatments utilizing these proppants, and methods of enhance hydrocarbon recovery.

A ceramic for construction or technical applications, composed of at least one of Municipal Solid Waste Incinerator Bottom Ash (MSWIBA) and other recycled industrial solid waste and different methods of forming such ceramics. Various techniques illustrate how ceramics are formed using at least one of extrusion shaping, dry powder compaction and agglomeration, any of which can be preceded by a pre-treatment process of received feedstock.

A lightweight high-strength ceramsite, comprising solid raw materials and activator as the raw materials, which can be respectively expressed in parts by weight, the solid raw materials: 100 parts, the activator: 1-15 parts; wherein said solid raw materials comprise fly ash: 100 parts, high-alumina fly ash, bauxite and red mud: 6-18 parts, silica fume: 1-5 parts, surfactant: 0.1-3 parts, plasticizer: 6-24 parts; and said activator comprises alkali metal hydroxide: 5-20 parts and alkali metal silicate: 80-95 parts. The lightweight high-strength ceramsite product prepared has a density level of 700-1100 kg/m3 and cylindrical compressive strength of 10-20 MPa, and thus is not susceptible to damage.