High alumina cement is produced in a submerged combustion melter, cooled and ground.

A method of producing cement clinker and a second calcined material, wherein the cement clinker is produced in a first production line and the second calcined material is produced from a raw material in a second production line by carrying out the following procedures e) optionally drying the raw material in a dryer, g) calcining the optionally dried raw material in a rotary kiln to obtain the second calcined material, wherein the sensible heat of a hot gas in the first production line is used as a heat source in the calcining step g) for calcining the raw material, and wherein the rotary kiln exhaust gas coming from the calcining step g) is introduced into the first production line for the secondary combustion of the rotary kiln exhaust gas.

A method of producing cement clinker and a second calcined material, wherein the cement clinker is produced in a first production line and the second calcined material is produced from a raw material in a second production line by carrying out the following procedures e) optionally drying the raw material in a dryer, g) calcining the optionally dried raw material in a rotary kiln to obtain the second calcined material, wherein the sensible heat of a hot gas in the first production line is used as a heat source in the calcining step g) for calcining the raw material, and wherein the rotary kiln exhaust gas coming from the calcining step g) is introduced into the first production line for the secondary combustion of the rotary kiln exhaust gas.

A CO.sub.2 separation/recover method in cement production exhaust gas has a step of harmful component removal that removes an acidic component and a harmful component from exhaust gas discharged from a cement production facility; and a step of CO.sub.2 separation and recover that separates and recovers CO.sub.2 by bringing the exhaust gas from which the acidic component and the harmful component are removed into contact with a CO.sub.2 absorption material, so that the acidic component and the harmful component are removed before separating and recovering CO.sub.2, resulting in deterioration of the absorbing ability of the CO.sub.2 absorption material being suppressed; and the cement production exhaust gas can be appropriately disposed.

Embodiments relate to an apparatus for descaling a vessel. The apparatus includes a frame having a frame top and a frame bottom, the frame including a longitudinal axis running from the frame top to the frame bottom. The apparatus includes an outrigger stabilizing assembly attached to the frame. The outrigger stabilizing assembly has a plurality of arms configured to extend and retract radially with respect to the longitudinal axis to abut against a wall of the vessel. The apparatus includes a turret attached to the frame bottom. The apparatus includes a hammer assembly pivotally attached to the turret. The hammer assembly has an extendable and retractable boom pivotally attached to the turret. The boom has first and second ends, and there is a reciprocating hammer pivotally attached to the second end of the boom.

Generating methane by adding hydrogen to CO.sub.2 in exhaust gas discharged a from cement production facility or CO.sub.2 that is separated and recovered from the exhaust gas, and using the methane as an alternative fuel to fossil fuel such as coal, petroleum, natural gas and the like, by methanation of CO.sub.2 in the exhaust gas from the cement production facility that includes exhaust gas originated from lime stone not from the fossil oil and effectively utilizing it, it is possible to reduce usage of the fossil fuel, suppress CO.sub.2 originated from energy, and improve an effect of reducing greenhouse gas.

Generating methane by adding hydrogen to CO.sub.2 in exhaust gas discharged a from cement production facility or CO.sub.2 that is separated and recovered from the exhaust gas, and using the methane as an alternative fuel to fossil fuel such as coal, petroleum, natural gas and the like, by methanation of CO.sub.2 in the exhaust gas from the cement production facility that includes exhaust gas originated from lime stone not from the fossil oil and effectively utilizing it, it is possible to reduce usage of the fossil fuel, suppress CO.sub.2 originated from energy, and improve an effect of reducing greenhouse gas.

A method and system for producing nano-active powder materials. The method can be used with a reactor system comprising stages in which input particles flow under gravity progressively through stages of the reactor. A powder injector first stage in which ground input precursor powder is injected into the reactor. An externally heated preheater stage may be in the reactor, in which the precursor powder is heated to a temperature of calcination reaction. An externally heated calciner stage in the reactor, in which primary precursor volatile constituents can be rapidly removed calcination reactions as a high purity gas stream to produce the desired nano-active product. A post-processing reactor stage in which there is a change of the gas stream composition to produce the desired hot powder product by virtue of the nano-activity of the first powder material. A powder ejector stage in which the hot powder product is ejected from the reactor.

A method and system for producing nano-active powder materials. The method can be used with a reactor system comprising stages in which input particles flow under gravity progressively through stages of the reactor. A powder injector first stage in which ground input precursor powder is injected into the reactor. An externally heated preheater stage may be in the reactor, in which the precursor powder is heated to a temperature of calcination reaction. An externally heated calciner stage in the reactor, in which primary precursor volatile constituents can be rapidly removed calcination reactions as a high purity gas stream to produce the desired nano-active product. A post-processing reactor stage in which there is a change of the gas stream composition to produce the desired hot powder product by virtue of the nano-activity of the first powder material. A powder ejector stage in which the hot powder product is ejected from the reactor.

An expansion constraint assembly can be attached to the exterior of a kiln cylinder. The expansion constraint assembly may include an outer constraining structure, an inner circular structure, and support structures extending between the inner circular structure and the outer constraining structure. The support structures may extend at an offset angle away from a radial direction of the outer constraining structure. The expansion constraint assembly may also include additional rings disposed between the inner circular structure and the outer constraining structure. The expansion constraint assembly can constrain asymmetric expansion of the kiln cylinder, for example, by relieving uniform expansion as a rotational shift, while restraining asymmetric expansion via tensile and compressive stresses in inter-connecting members.