Cement compositions for primary cementing of well bores where a liquid mixture of pre-hydrated cementitious particles are combined with cement particles to form a cement composition. The pre-hydrated cementitious particles are encapsulated with the hydration product and are capable of being stored in a liquid for one day or longer

An investment powder which is safer than conventional powders comprising tricalcium phosphate, and being substantially or entirely free of free silica in the respiratory portion yet providing an overall expansion at 750° C. of 1% or higher sufficient to prevent mould cracking during casting. A method of making a casting comprising forming a slurry by mixing a gypsum bonded investment powder with water, pouring the slurry into a stainless steel flask around a low melting point material model, allowing the slurry to set to define a mould, heating the mould to burn out the model and casting material into the mould wherein the stainless steel flask consists of a 400 series martensitic stainless steel.

An investment powder which is safer than conventional powders comprising tricalcium phosphate, and being substantially or entirely free of free silica in the respiratory portion yet providing an overall expansion at 750° C. of 1% or higher sufficient to prevent mould cracking during casting. A method of making a casting comprising forming a slurry by mixing a gypsum bonded investment powder with water, pouring the slurry into a stainless steel flask around a low melting point material model, allowing the slurry to set to define a mould, heating the mould to burn out the model and casting material into the mould wherein the stainless steel flask consists of a 400 series martensitic stainless steel.

The present disclosure provides a cementitious material and production method thereof. The method comprises steps of: (1) dry desulfurization and denitrification of a flue gas with a flue gas absorbent to give a by-product, wherein the flue gas absorbent comprises 10-23 parts by weight of a nano-sized metal oxide, 10-23 parts by weight of a micro-sized metal oxide, and 40-60 parts by weight of magnesium oxide, the nano-sized metal oxide being selected from one or more of the group consisting of SiO2, CaO, Fe2O3, Al2O3, CuO, V2O5 and MnO2, and the micro-sized metal oxide being selected from one or more of the group consisting of SiO2, CaO, Fe2O3, Al2O3, CuO, V2O5 and MnO2; and (2) uniformly mixing the by-product with magnesium oxide, an industrial solid waste and an additive to give the cementitious material.

The present disclosure provides a cementitious material and production method thereof. The method comprises steps of: (1) dry desulfurization and denitrification of a flue gas with a flue gas absorbent to give a by-product, wherein the flue gas absorbent comprises 10-23 parts by weight of a nano-sized metal oxide, 10-23 parts by weight of a micro-sized metal oxide, and 40-60 parts by weight of magnesium oxide, the nano-sized metal oxide being selected from one or more of the group consisting of SiO2, CaO, Fe2O3, Al2O3, CuO, V2O5 and MnO2, and the micro-sized metal oxide being selected from one or more of the group consisting of SiO2, CaO, Fe2O3, Al2O3, CuO, V2O5 and MnO2; and (2) uniformly mixing the by-product with magnesium oxide, an industrial solid waste and an additive to give the cementitious material.

Disclosed herein are embodiments of a coating composition for use in investment casting. The coating composition embodiments provide a solidified coat that can be as a mold for casting castable materials and that is easily removed from the casted material using water. The coating composition embodiments disclosed herein are reusable and are non-toxic and exhibit high thermal stability.

The present invention belongs to the field of composite materials, and particularly to a non-flowable quick-setting phosphate cement repair material with strong cohesive forces and the preparation method thereof. The material comprises the following raw materials in percentage by weight: 20% to 40% of sand, 5% to 12% of ammonium dihydrogen phosphate, 10% to 25% of magnesium oxide, 2% to 8% of fly ash, 30% to 60% of rubber powder, 6% to 10% of silica fume, 0.35% to 0.6% of a polycarboxylate high efficiency water-reducing agent, 1% to 5% of sodium silicate, 1.5% to 2% of a polypropylene fiber, 0.5% to 2% of a retarder, and 8% to 10% of water. The material is used as the repair material for the special positions of bottom boards of bridges or facades of buildings which are damaged, and the repair effect thereof is remarkable.

The present invention belongs to the field of composite materials, and particularly to a non-flowable quick-setting phosphate cement repair material with strong cohesive forces and the preparation method thereof. The material comprises the following raw materials in percentage by weight: 20% to 40% of sand, 5% to 12% of ammonium dihydrogen phosphate, 10% to 25% of magnesium oxide, 2% to 8% of fly ash, 30% to 60% of rubber powder, 6% to 10% of silica fume, 0.35% to 0.6% of a polycarboxylate high efficiency water-reducing agent, 1% to 5% of sodium silicate, 1.5% to 2% of a polypropylene fiber, 0.5% to 2% of a retarder, and 8% to 10% of water. The material is used as the repair material for the special positions of bottom boards of bridges or facades of buildings which are damaged, and the repair effect thereof is remarkable.

A composition for use in making a structural assembly board, a structural assembly made from the composition, and a method of making the structural assembly board is provided. The composition includes magnesium oxide; magnesium sulfate; and water. The composition includes reinforcing fibers. The composition and method of making the structural assembly board promote formation of 5MgO.MgSO.sub.4.2H.sub.2O to improve structural qualities of the structural assembly board.

A composition for use in making a structural assembly board, a structural assembly made from the composition, and a method of making the structural assembly board is provided. The composition includes magnesium oxide; magnesium sulfate; and water. The composition includes reinforcing fibers. The composition and method of making the structural assembly board promote formation of 5MgO.MgSO.sub.4.2H.sub.2O to improve structural qualities of the structural assembly board.