A two-component mortar system, which includes a component A; and a component B, which is in aqueous-phase for initiating a curing process. Component A comprises water, aluminous cement, at least one plasticizer, and at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid, and a phosphoric acid. Component B includes an initiator, at least one retarder, at least one mineral filler, and water.

A fastening system for chemically fastening an anchor, the fastening system including a chemical anchor that is a ready-for-use two-component mortar system based on albuminous cement, and an anchor rod comprising an attachment region and an anchoring region. The anchor rod is insertable into a borehole and has a profiled section including a plurality of expansion sections disposed axially in a row which are conically shaped.

A fastening system for chemically fastening an anchor, the fastening system including a chemical anchor that is a ready-for-use two-component mortar system based on albuminous cement, and an anchor rod comprising an attachment region and an anchoring region. The anchor rod is insertable into a borehole and has a profiled section including a plurality of expansion sections disposed axially in a row which are conically shaped.

An inorganic mortar system for a chemical fastening of an anchor in a mineral surface includes calcium sulfate, a component A, and a component B for initiating a curing process. Component A includes water, aluminous cement, at least one plasticizer, and at least one blocking agent selected from phosphoric acid, metaphosphoric acid, phosphorous acid, and a phosphonic acid. Component B includes an initiator, at least one retarder, at least one mineral filler, and water. Component A is also a curable composition.

An inorganic mortar system for a chemical fastening of an anchor in a mineral surface includes calcium sulfate, a component A, and a component B for initiating a curing process. Component A includes water, aluminous cement, at least one plasticizer, and at least one blocking agent selected from phosphoric acid, metaphosphoric acid, phosphorous acid, and a phosphonic acid. Component B includes an initiator, at least one retarder, at least one mineral filler, and water. Component A is also a curable composition.

A method of preparing a unique foundry premix composition that has a low bulk density of 30-45 lbs/ft.sup.3 and contains fine particles with an average particle size of 85-100 μm is described. The unique foundry premix composition is produced by using specially designed assemblies of mechanical equipment with improved efficiency so that the premix can be prepared at a site closer to a foundry. As a result, increase in premix density caused by handling and shipping across a long distance from a traditional premix manufacturing facility to a foundry can be suppressed; transportation cost can be saved; and safety would be of less concern. The use of the foundry premix composition to prepare a sand molding medium for casting molded articles is also described.

Cement compositions containing a hydraulic cement, a synthetic phyllosilicate (e.g. Laponite®), and silica flour. The cement compositions may optionally include other additives such as an expandable agent, a defoamer, and a fluid loss controller. Cement slurries and wellbore cements made therefrom are also specified. The inclusion of the synthetic phyllosilicate has enhanced the mechanical strength, improved the density homogeneity, as well as decreased the permeability of the wellbore cement, making it suitable for cementing oil and gas wells under high pressure and high temperature (HPHT) conditions.

Cement compositions containing a hydraulic cement, a synthetic phyllosilicate (e.g. Laponite®), and silica flour. The cement compositions may optionally include other additives such as an expandable agent, a defoamer, and a fluid loss controller. Cement slurries and wellbore cements made therefrom are also specified. The inclusion of the synthetic phyllosilicate has enhanced the mechanical strength, improved the density homogeneity, as well as decreased the permeability of the wellbore cement, making it suitable for cementing oil and gas wells under high pressure and high temperature (HPHT) conditions.

A multi-slug staged method for plugging a fractured formation includes: determining an average opening of fractures around a well as D, an average particle size of bridging particles for first-stage plugging as D.sub.1 that is slightly less than D, and average particle sizes of plugging particles for second to last-stage plugging as D.sub.2-D.sub.n, where D.sub.n is small enough to form a tight plugging layer; and sequentially injecting a plugging slurry only containing the bridging particles having the average particle size of D.sub.1, plugging slurries containing the plugging particles having the average particle sizes of D.sub.2-D.sub.n-1, and a plugging slurry containing the plugging particles having the average particle size of D.sub.n into the fractures to achieve the fractured formation plugging.

A multi-slug staged method for plugging a fractured formation includes: determining an average opening of fractures around a well as D, an average particle size of bridging particles for first-stage plugging as D.sub.1 that is slightly less than D, and average particle sizes of plugging particles for second to last-stage plugging as D.sub.2-D.sub.n, where D.sub.n is small enough to form a tight plugging layer; and sequentially injecting a plugging slurry only containing the bridging particles having the average particle size of D.sub.1, plugging slurries containing the plugging particles having the average particle sizes of D.sub.2-D.sub.n-1, and a plugging slurry containing the plugging particles having the average particle size of D.sub.n into the fractures to achieve the fractured formation plugging.