The invention provides a low density cement composition. The composition includes a cement component, a glass sphere component, a bentonite component, a fine calcium carbonate component, a medium calcium carbonate component, a silica sand component, and a silica flour component.

A powder adhesive composition having cement, a dispersible polymer powder; and at least 10% volume of the powder adhesive is an expanded perlite. The cement is at a ratio of between 600-1000% of the mass of the expanded perlite. The powder adhesive composition is an adhesive, and the adhesion strength of the adhesive, is over 0.4 MPa, after 28 days, and after water immersion for at least 20 days.

A powder adhesive composition having cement, a dispersible polymer powder; and at least 10% volume of the powder adhesive is an expanded perlite. The cement is at a ratio of between 600-1000% of the mass of the expanded perlite. The powder adhesive composition is an adhesive, and the adhesion strength of the adhesive, is over 0.4 MPa, after 28 days, and after water immersion for at least 20 days.

A variety of systems, methods and compositions are disclosed, including, in one method, a method of cementing may comprise: providing a cement composition comprising a hydraulic cement, water, and a functionalized polyethyleneimine retarder; placing the cement composition in a selected location; and allowing the cement composition to set.

A variety of systems, methods and compositions are disclosed, including, in one method, a method of cementing may comprise: providing a cement composition comprising a hydraulic cement, water, and a functionalized polyethyleneimine retarder; placing the cement composition in a selected location; and allowing the cement composition to set.

A method for conditioning an acid waste by cementation, wherein the acid waste is chosen among liquids having a pH of no more than 4, semi-liquids having a pH of no more than 4, solids of which the partial or full dissolution in water leads to a solution or suspension having a pH of no more than 4, and mixtures thereof, which method comprises the steps of: a) preparing a cement paste having as components at least: a magnesium phosphate cement and the acid waste, and b) hardening the cement paste thus obtained, and is characterised in that in step a), the cement paste is prepared without subjecting beforehand the acid waste to any treatment consisting in reducing the acidity thereof.

A method for conditioning an acid waste by cementation, wherein the acid waste is chosen among liquids having a pH of no more than 4, semi-liquids having a pH of no more than 4, solids of which the partial or full dissolution in water leads to a solution or suspension having a pH of no more than 4, and mixtures thereof, which method comprises the steps of: a) preparing a cement paste having as components at least: a magnesium phosphate cement and the acid waste, and b) hardening the cement paste thus obtained, and is characterised in that in step a), the cement paste is prepared without subjecting beforehand the acid waste to any treatment consisting in reducing the acidity thereof.

A karst channel type water inrush efficient-blocking ultra-high expansion grouting material, preparation, methods and application thereof, the grouting material includes macromolecule polymer particles A and a cross-linking solidifying fluid B, wherein the macromolecule polymer particles A are an inlaid type core-shell structure, primary macromolecule water-absorbent resin serves as an inner core, part of a gelling catalyzer is attached to an the inner core surface forming a shell, and the gelling catalyzer permeates the inner core forming an inlaid structure; before use, the macromolecule polymer particle A and the cross-linking solidifying fluid B are stirred; and then obtained mixed liquid is used as the grouting material to be injected into a fracture of a rock mass fracture zone. By means of the grouting material, high-pressure large-flow karst water inrush can be efficiently treated, the blocking efficiency of water inrush is improved, and major underground engineering construction of China is further facilitated.

A karst channel type water inrush efficient-blocking ultra-high expansion grouting material, preparation, methods and application thereof, the grouting material includes macromolecule polymer particles A and a cross-linking solidifying fluid B, wherein the macromolecule polymer particles A are an inlaid type core-shell structure, primary macromolecule water-absorbent resin serves as an inner core, part of a gelling catalyzer is attached to an the inner core surface forming a shell, and the gelling catalyzer permeates the inner core forming an inlaid structure; before use, the macromolecule polymer particle A and the cross-linking solidifying fluid B are stirred; and then obtained mixed liquid is used as the grouting material to be injected into a fracture of a rock mass fracture zone. By means of the grouting material, high-pressure large-flow karst water inrush can be efficiently treated, the blocking efficiency of water inrush is improved, and major underground engineering construction of China is further facilitated.

A cement slurry composition, containing hydraulic cement, water, and from 1 to less than 4% of an organically modified nanoclay. A method for cementing a high pressure high temperature well by pumping the cement composition of claim 1 between a casing and a formation of a well bore to fill a gap between the casing and the formation, and allowing the cement to harden.