In order to address the technical problem of allowing an unshaped refractory material using a spinel-containing alumina cement to provide further improved corrosion resistance and slag infiltration resistance while reducing the occurrence of crack/peeling, an unshaped refractory material is provided which comprises a refractory raw material mixture having a particle size of 8 mm or less, with the refractory raw material mixture having an alumina cement at least a part of which is a spinel-containing alumina cement, and, with respect to 100 mass % of the refractory raw material mixture, the alumina cement contains CaO in an amount of 0.5 to 2.5 mass %, and the spinel-containing alumina cement contains spinel in an amount of 3.5 to 10.5 mass %.

A composition configured to be mixed with cement, and associated systems and methods are disclosed herein. In some embodiments, the composition includes at least 10% by weight lime particles, and at least 35% by weight pozzolan particles. Properties of the composition can include a magnesium oxide concentration of at least 0.5%, and an iron oxide concentration of at least 0.5-2.0%, an aluminum oxide concentration of 2-8%, a silicon dioxide concentration of 20-40%, a potassium oxide concentration of 20,000-30,000 ppm, and a sodium oxide concentration of 10,000-20,000 ppm. In some embodiments, the lime-based cement extender composition, or product, is combined with cement to produce a cement blend for use in the mining industry as mine backfill.

The present invention corresponds to a cement formulation based on sulfoaluminate comprising a specific Ye'elimite crystal proportion having enhanced mechanical resistance, setting and low CO2 emission features. A concrete obtained when mixing said formulation with water and gypsum is further described, having a superior performance at initial ages compared to concrete obtained from Portland cement.

The present invention comprises a product. The product comprises a first mineral in particulate form and having a first pozzolanic reactivity and a second mineral in particulate form and having a second pozzolanic reactivity greater than the first reactivity, wherein the surface of at least some of the particles of the first mineral is at least partially covered with particles of the second mineral. A method of making the composition of the present invention is also disclosed.

A low-calcium silicate cement consists of calcium oxide, silica, alumina, and iron oxide. A preparation method of the low-calcium silicate cement consists of: subjecting raw materials to crushing, joint grinding and uniform mixing to obtain a low-calcium silicate cement raw meal; calcining the above low-calcium silicate cement raw meal at 1050-1300? C. for 30-90 min, and cooling to obtain low-calcium silicate cement clinker; and levigating the above low-calcium silicate cement clinker till a specific surface area is 400-500 m.sup.2/Kg, thereby obtaining a low-calcium silicate cement.

A method for producing a composite insulating mineral block, includes providing a mineral masonry block including at least one cell with walls having a water absorption rate of less than 5 g/(m.sup.2.Math.s) at 10 minutes, and filling the cell with a mineral cement foam, wherein a cement used to produce the mineral cement foam has an aluminum oxide content of less than 20% by weight of the cement.

A cementitious binder, includes a hydraulic binder; a first siliceous based material, which has a (SiO.sub.2)/(Al.sub.2O.sub.3) ratio by weight greater than 2.5; a second siliceous based material, which is different from the first siliceous based material and has (a) a (SiO.sub.2)/(Al.sub.2O.sub.3) ratio by weight greater than 10 and (b) a BET specific surface area greater than 5 m.sup.2/g; and an aluminum based material, which has a (SiO.sub.2)/(Al.sub.2O.sub.3) ratio by weight lower than 2.5, wherein 0.09<Al.sub.EFF/(Al.sub.EFF+Si.sub.EFF)<0.28, where Al.sub.EFF=molar content of alumina in the hydraulic binder, and Si.sub.EFF=molar content of silica in the first siliceous based material for particles having a size lower than 3 m+molar content of silica in the second siliceous based material.

Disclosed is a composition including an amorphous calcium aluminate with a final lime:alumina molar ratio between lower and upper limits. The amorphous calcium aluminate is a combination including at least: a first amorphous calcium aluminate with a first lime to alumina molar ratio, strictly lower than the lower limit of the predetermined range; and a second amorphous calcium aluminate with a second lime to alumina molar ratio, strictly higher than the upper limit of the predetermined range. The combination includes a first amount of the first amorphous calcium aluminate and a second amount of the second amorphous calcium aluminate, the first and second amounts being determined in such a way that the final lime to alumina molar ratio of the amorphous calcium aluminate, corresponding to the average of the first and second lime to alumina molar ratios weighted by the first and second amounts, is within the predetermined range.

A low-calcium silicate cement, comprising: based on the total mass of oxides as 1, 50-60% of calcium oxide, 30-45% of silica, 2-6% of alumina, and 1-4% of iron oxide. A preparation method of the low-calcium silicate cement comprises: subjecting raw materials to crushing, joint grinding and uniform mixing to obtain a low-calcium silicate cement raw meal; calcining the above low-calcium silicate cement raw meal at 1050-1300? C. for 30-90 min, and cooling to obtain low-calcium silicate cement clinker; and levigating the above low-calcium silicate cement clinker till a specific surface area is 400-500 m.sup.2/Kg, thereby obtaining a low-calcium silicate cement.

The present invention comprises a product. The product comprises a first mineral in particulate form and having a first pozzolanic reactivity and a second mineral in particulate form and having a second pozzolanic reactivity greater than the first reactivity, wherein the surface of at least some of the particles of the first mineral is at least partially covered with particles of the second mineral. A method of making the composition of the present invention is also disclosed.