The invention related to photocatalytic material field, and discloses a metal-doped amorphous carbon nitride photocatalytic material and the preparation method thereof. The method comprises: (1) mixing the nitrogen-rich organic matter with the metal salt; (2) calcining the mixture obtained in step (1) to obtain the photocatalytic material; the nitrogen-rich organic matter is selected from one or more of melamine, dicyandiamide, monocyanamide, thiourea, urea, hexamethylenetetramine, and biuret; the metal salt is selected from one or more of an alkali metal salt, an alkaline earth metal salt, and a transition metal salt. The method is simple, efficient, low-cost, requires no external catalyst, organic solvent and protective reagent, and does not require pretreatment of raw materials, and is a preparation method favorable for large-scale commercial production.

Provided are a heating furnace and a graphite production method both of which allow a carbonization step and a graphitization step to be consecutively performed. The heating furnace is a heating furnace for producing graphite from a polymeric material, and includes a heating furnace body for subjecting the polymeric material to heat treatment. The heating furnace body includes a closed vessel for containing the polymeric material. A gas outlet pipe is connected to the closed vessel, the gas outlet pipe being for letting, out of the heating furnace body, a pyrolytic gas generated from the polymeric material.

Provided are a heating furnace and a graphite production method both of which allow a carbonization step and a graphitization step to be consecutively performed. The heating furnace is a heating furnace for producing graphite from a polymeric material, and includes a heating furnace body for subjecting the polymeric material to heat treatment. The heating furnace body includes a closed vessel for containing the polymeric material. A gas outlet pipe is connected to the closed vessel, the gas outlet pipe being for letting, out of the heating furnace body, a pyrolytic gas generated from the polymeric material.

Provided herein are systems for carbonation curing and CO.sub.2 mineralization of concrete composites and methods of manufacturing a carbonated concrete composite. A method of manufacturing a carbonated concrete composites includes contacting concrete with CO.sub.2-containing gas streams in the carbonation reactor having a gas stream inlet and an outlet to provide optimal gas flow distribution and gas velocity. The concrete precursor includes a binder, one or more aggregates, and water. A gas stream is received at the carbonation reactor. The gas stream includes carbon dioxide. The concrete precursor is maintained at a suitable temperature in the carbonation reactor to thereby react the concrete precursor with the gas stream to produce carbonate minerals in the carbonated concrete composite.

Provided herein are systems for carbonation curing and CO.sub.2 mineralization of concrete composites and methods of manufacturing a carbonated concrete composite. A method of manufacturing a carbonated concrete composites includes contacting concrete with CO.sub.2-containing gas streams in the carbonation reactor having a gas stream inlet and an outlet to provide optimal gas flow distribution and gas velocity. The concrete precursor includes a binder, one or more aggregates, and water. A gas stream is received at the carbonation reactor. The gas stream includes carbon dioxide. The concrete precursor is maintained at a suitable temperature in the carbonation reactor to thereby react the concrete precursor with the gas stream to produce carbonate minerals in the carbonated concrete composite.

An installation for the conversion of uranium hexafluoride (UF.sub.6) to uranium dioxide (UO.sub.2) comprises a hydrolysis reactor (4) for the conversion of UF.sub.6 into uranium oxyfluoride powder (UO.sub.2F.sub.2), a pyrohydrolysis furnace (6) for converting the UO.sub.2F.sub.2 powder supplied by the reactor (4) into UO.sub.2 powder, a supply device (8) comprising reagent injection ducts (10) for the injection of UF.sub.6, water vapor or H.sub.2, and a control system (16) designed to control the supply device (8) so as to supply at least one of the reagent injection ducts (10) with a neutral gas during a shut-down or start-up phase of the conversion installation.

An installation for the conversion of uranium hexafluoride (UF.sub.6) to uranium dioxide (UO.sub.2) comprises a hydrolysis reactor (4) for the conversion of UF.sub.6 into uranium oxyfluoride powder (UO.sub.2F.sub.2), a pyrohydrolysis furnace (6) for converting the UO.sub.2F.sub.2 powder supplied by the reactor (4) into UO.sub.2 powder, a supply device (8) comprising reagent injection ducts (10) for the injection of UF.sub.6, water vapor or H.sub.2, and a control system (16) designed to control the supply device (8) so as to supply at least one of the reagent injection ducts (10) with a neutral gas during a shut-down or start-up phase of the conversion installation.

A method of making N-(2,4-dinitrophenyl)-4-nitrobenzamide from a mixture of 2,4-dinitroaniline, 4-nitrobenzoyl chloride, and solid acid catalyst in an organic solvent, wherein the solid acid catalyst is not soluble in the organic solvent, the solid acid catalyst being an acidic clay, an ion exchange resin, a beta zeolite, a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer, or some mixture of these.

A method of making N-(2,4-dinitrophenyl)-4-nitrobenzamide from a mixture of 2,4-dinitroaniline, 4-nitrobenzoyl chloride, and solid acid catalyst in an organic solvent, wherein the solid acid catalyst is not soluble in the organic solvent, the solid acid catalyst being an acidic clay, an ion exchange resin, a beta zeolite, a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer, or some mixture of these.

A facility for producing a composite material that includes carbon nanotubes. The facility includes a reaction chamber with an injection device for injecting an active gas mixture (for the growth of the carbon nanotubes) into the interior volume thereof. A transport device is to transport a substrate into the reaction chamber to form the composite material. The injection device may transport the active gas mixture in a first direction into the interior volume. A circulation device is to circulate the active gas mixture, and may transport the active gas mixture into the interior volume in a second direction that is different from the first direction. The circulation device may adopt a first configuration of injection of the active gas mixture into the interior volume of the chamber, and a second configuration of extraction of the active gas mixture from the interior volume.