A free-flowing powder composition includes at least one substrate having pores and an external surface between said pores, said surface functionalized with at least one accelerator for a hydraulic setting composition, said accelerator being liquid, hygroscopic, or deliquescent, and wherein after 15 minutes of immersion of free-flowing powder composition in water at 20° C. at least 80% in weight of said accelerator is solubilized, said free-flowing powder composition being immersed in an amount of water sufficient so that the saturation concentration of said accelerator cannot be reached. There is also a method for preparing said free-flowing powder composition. The use of said free-flowing powder composition as an additive for mortar or concrete composition provides an accelerating effect, an anti-ageing effect and an anti-dusting effect. A dry mortar or concrete composition includes a hydraulic binder, said free-flowing powder composition and a granulate, wet mortar or concrete composition and hardened body obtained therefrom.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source (e.g. in an amount between 4-27 wt %) and a metal salt additive (in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil. The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source (e.g. in an amount between 4-27 wt %) and a metal salt additive (in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil. The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

Methods of wellbore cementing are provided. A method of cementing may comprise calculating a lime to silica correlation for two or more cementitious components of a cement composition; and adjusting a concentration of at least one of the cementitious components such that the lime to silica correlation meets or exceeds a target.

Methods of wellbore cementing are provided. A method of cementing may comprise calculating a lime to silica correlation for two or more cementitious components of a cement composition; and adjusting a concentration of at least one of the cementitious components such that the lime to silica correlation meets or exceeds a target.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

The invention relates to a method and furnace allowing the use of filter earth (diatomaceous earth) waste, in which the organic material is removed using the method of the application. The furnace comprises a container in which the industrial waste is deposited, and a folding table is used to transport the material. The invention also includes an agitator with a base, used to lower blades and remove the treated material. The gases generated are collected by an extractor which includes a cooling jacket and are subsequently sent to an absorber system in which they are neutralized. Said device and method are used to obtain lightweight materials with low porosity and high compression strength, rendering solid granular industrial waste that is dangerous to the environment suitable for use in the construction or mechanical industries.

The invention relates to a method and furnace allowing the use of filter earth (diatomaceous earth) waste, in which the organic material is removed using the method of the application. The furnace comprises a container in which the industrial waste is deposited, and a folding table is used to transport the material. The invention also includes an agitator with a base, used to lower blades and remove the treated material. The gases generated are collected by an extractor which includes a cooling jacket and are subsequently sent to an absorber system in which they are neutralized. Said device and method are used to obtain lightweight materials with low porosity and high compression strength, rendering solid granular industrial waste that is dangerous to the environment suitable for use in the construction or mechanical industries.

The invention relates to a method and furnace allowing the use of filter earth (diatomaceous earth) waste, in which the organic material is removed using the method of the application. The furnace comprises a container in which the industrial waste is deposited, and a folding table is used to transport the material. The invention also includes an agitator with a base, used to lower blades and remove the treated material. The gases generated are collected by an extractor which includes a cooling jacket and are subsequently sent to an absorber system in which they are neutralized. Said device and method are used to obtain lightweight materials with low porosity and high compression strength, rendering solid granular industrial waste that is dangerous to the environment suitable for use in the construction or mechanical industries.