13results about How to "Low reduction temperature" patented technology

The invention discloses a honeycomb core-shell structure composite material nano-catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalyst materials. The method comprises the following steps: adding small-grain ZSM-5 zeolite into a NaBH4 aqueous solution, heating, stirring and drying; grinding, pickling and drying the dried product, and then grinding again to obtain modified small-grain ZSM-5 zeolite; the preparation method comprises the following steps: dissolving Ni (NO3) 2.6 H2O, Cu (NO3) 2.3 H2O, Co (NO3) 2.6 H2O and urea into a mixed solvent, and magnetically stirring; transferring the obtained mixed solution into a reaction kettle, adding the modified small-grain ZSM-5 zeolite powder, sealing, heating, and cooling at room temperature; and washing the obtained solid material with deionized water and ethanol, centrifuging, and sequentially drying and calcining the centrifuged material to obtain the product. The catalyst provided by the invention has excellent performance in hydrogen production through methanol decomposition.

The invention relates to the technical field of nano powder material preparation, in particular to a method for preparing molybdenum powder based on a spray granulation precursor and the molybdenum powder. The method for preparing the molybdenum powder comprises the steps that ammonium molybdate and a pore forming agent are dissolved in ultrapure water at the room temperature, and mixed slurry is obtained; carrying out spray granulation treatment on the mixed slurry to obtain composite powder particles containing the pore-forming agent and ammonium molybdate; the composite powder particles are placed in an oxygen-containing atmosphere to be roasted, and superfine nano molybdenum trioxide is obtained; placing the superfine nano molybdenum trioxide in a hydrogen atmosphere for primary reduction treatment to obtain superfine molybdenum dioxide powder; and the superfine molybdenum dioxide powder is subjected to second-stage reduction treatment, the superfine molybdenum powder is obtained, and the reduction conditions of the first-stage reduction treatment and the second-stage reduction treatment are different. According to the preparation method, the superfine molybdenum powder with good uniformity and dispersity can be prepared.

The invention relates to a CO2 catalytic conversion catalyst and a preparation method and application thereof.The preparation method of the catalyst comprises the steps that a silicon source, an aluminum source and an inorganic acid aqueous solution are weighed to form white sol, then centrifugation, washing and drying are conducted, white silicon-aluminum composite oxide powder is obtained, a binder is added, rolling ball forming is conducted, and a silicon-aluminum composite oxide carrier precursor is obtained; and weighing the first active component precursor, the second active component precursor and the auxiliary component precursor, loading the precursors on the silicon-aluminum composite oxide carrier precursor in a dipping manner, drying, and roasting to obtain the CO2 catalytic conversion catalyst. Compared with the prior art, the catalyst provided by the invention has the advantages of high activity, high selectivity, high stability and the like in the CO2 reverse water gas shift reaction.

The invention belongs to the technical field of organic chemical industry, and particularly relates to a method for preparing hexamethylenediamine through hydrogenation of 6-aminocapronitrile. Comprising the following steps: adding a 6-aminocapronitrile solution into a reaction kettle, activating a catalyst through hydrogen, transferring the activated catalyst into the reaction kettle under the protection of nitrogen, sealing, replacing air in the reactor with hydrogen, pressurizing to 1.5-8.0 Mpa, and stirring for reaction; after the reaction is finished, cooling to room temperature, taking a reacted mixture, and carrying out reduced pressure distillation to obtain hexamethylenediamine; the catalyst is an Al2O3 loaded copper-nickel-based catalyst. According to the method, the hexamethylenediamine is prepared by directly hydrogenating the 6-aminocapronitrile serving as the raw material without adding alkali or ammonia water, and the method is simple in production process, high in process safety, low in production cost, high in reaction conversion rate and yield, high in purity of the hexamethylenediamine and suitable for large-scale production.

The present invention discloses quartz pellets for silicon alloy production, wherein the quartz pellets contain SiO₂>96%, Al₂O₃<0.8%, and Fe₂O₃<0.8% by weight. The quartz pellets are approximately spherical in shape. When used for silicon alloy production, the quartz pellets and the carbonaceous reducing agent fall freely from the material tube and enter the surface of the ore-fired furnace. The large balls are quartz pellets, and the small balls are carbonaceous reducing agent pellets. The large and small balls are tightly packed and evenly distributed. When the furnace temperature is below 1700°C, no deflagration or explosion will occur. The quartz pellets have the characteristics of high reducibility, high explosion resistance, high specific surface area, high porosity in the pellets, low reduction starting temperature, energy saving and environmental protection, etc. The reducing atmosphere is good, and a large amount of reducing gas will enter the internal pores of the pellets to carry out microcirculation reaction, without stab fire phenomenon, and high heat energy conduction efficiency.

The present invention discloses a catalyst for preparing light olefins from synthesis gas, and a preparation method and application thereof. The catalyst for preparing light olefins from synthesis gas of the present invention has a χ-Fe5C2 crystal face, and the catalyst comprises a carrier and an active component, wherein the chemical formula of the active component is as follows in terms of atomic ratio: Fe 100 Mn a Cu b Cr c D d E e O x , D is selected from at least one of alkaline earth metals; E is selected from at least one of lanthanide rare earth elements; a is in the range of 30.0 to 120.0; b is in the range of 5.0 to 50.0; c is in the range of 1.0 to 30.0; d is in the range of 0.1 to 10.0; and e is in the range of 0.1 to 10.0. When the catalyst of the present invention is used for directly preparing light olefins from synthesis gas, it has the advantages of higher CO conversion rate, better selectivity of light olefins, and better catalyst stability.

The invention relates to the technical field of cyclopentadiene synthesis, in particular to a method for synthesizing cyclopentadiene from cyclopentanone. The method comprises the following steps: by taking cyclopentanone as a raw material, carrying out hydrodeoxygenation tandem dehydrogenation reaction in a fixed bed continuous reactor under the action of an AwBxCyOz type composite metal oxide catalyst or a C / ZnaAlbOc supported metal catalyst at the reaction temperature of 425-625 DEG C under the hydrogen pressure of 0.001 MPa, the molar ratio of hydrogen to cyclopentanone being (20-400): 1 and the weight hourly space velocity of cyclopentanone being 0.1-10h <-1 >, thereby obtaining cyclopentadiene. The method is simple in process route and environment-friendly, the catalyst is simple and convenient to prepare, and a more novel and efficient process route is provided for synthesizing cyclopentadiene from biomass-based cyclopentanone.

This invention discloses a method for extracting magnesium and phosphorus from high-magnesium phosphorus tailings through vacuum carbothermic reduction, relating to the field of high-magnesium phosphorus tailings reuse technology. The method involves uniformly mixing phosphorus tailings, silica, magnesite, and coke, pressing them into briquettes, calcining them to remove crystal water, and coking them to obtain pellets. The phosphorus tailings are high-magnesium phosphorus tailings with an MgO content of 16%–18%. The pellets are placed in a vacuum furnace, maintaining a vacuum of 10–100 Pa, and heated to 1200–1500°C, held for 30–60 minutes. The steam from the reaction is recovered, and the steam is condensed at 400–600°C to obtain crude magnesium. The partially cooled steam is then passed into a cold water tank to recover the precipitate, which is then filtered to obtain yellow phosphorus. This method effectively reuses high-magnesium phosphorus tailings and further recovers the difficult-to-refine phosphorus, allowing phosphorus and magnesium to be extracted and recovered in the same equipment and process. Simultaneously, it fully utilizes the calcium and fluorine as additives, lowering the reaction temperature and significantly reducing production costs.

The present invention relates to a CO 2 A catalytic conversion catalyst and a preparation method and application thereof. The preparation method of the catalyst comprises the following steps: firstly weighing a silicon source, an aluminum source and an inorganic acid aqueous solution to form a white sol, then centrifuging, washing and drying to obtain a white silicon-aluminum composite oxide powder, then adding a binder, rolling and forming a ball to obtain a silicon-aluminum composite oxide carrier precursor; then weighing a first active component precursor, a second active component precursor and an auxiliary component precursor, and loading them on the silicon-aluminum composite oxide carrier precursor by impregnation, drying and calcining to obtain a CO 2 Catalytic conversion catalyst. Compared with the prior art, the catalyst of the present invention has a 2 It has the advantages of high activity, high selectivity and high stability in the reverse water-gas shift reaction.

The application discloses low-cost sulfidized nano zero-valent iron based on a pyrite oxidation-reduction path and application thereof. Low-cost sulfidized nano zero-valent iron is obtained by the mode of air oxidation and then hydrogen reduction of cheap pyrite powder in a tube furnace. By adjusting and controlling parameters such as oxidation temperature, oxidation time and reduction time, the low-cost lattice-doped sulfidized nano zero-valent iron with a median particle size of less than 300 nm and a zero-valent iron content of 70% is prepared, and the preparation cost is far lower than that of a laboratory liquid-phase synthesis method. The material can effectively degrade trichloroethylene and florfenicol, and has a small hydrogen production amount and a high electron efficiency. The preparation method is simple and easy to operate, and has a large-scale production prospect, and the degradation performance of pollutants is close to that of laboratory-prepared sulfidized nano zero-valent iron, so the material has a prospect of being applied to actual groundwater pollution remediation.

The invention discloses Cr3C2-Co composite powder and a preparation method of the Cr3C2-Co composite powder, the Cr3C2-Co composite powder is composed of two substances of Cr3C2 and Co, and the weight percentage of the Cr3C2 is 5-95%. The preparation method of the Cr3C2-Co composite powder is characterized in that a carbon thermal reduction oxide or an oxide precursor is adopted, and the preparation method comprises the following steps that S1, the oxide or the oxide precursor and carbon black or a precursor capable of being decomposed into the carbon black are subjected to ball milling and mixing under the protective atmosphere or in a wet milling medium, and mixed powder with refined particle size and uniform mixing is obtained; s2, drying in vacuum or N2; s3, carrying out high-temperature reaction in Ar and H2 or in vacuum; and S4, carrying out ball-milling crushing or jet milling, and carrying out size grading on the powder. Compared with traditional Cr3C2 powder, the preparation temperature of the Cr3C2-Co composite powder with the same granularity is 150-200 DEG C lower than that of traditional Cr3C2 powder, non-uniform growth of WC grains in WC-Co-based hard alloy can be more effectively inhibited, and the hardness, strength and toughness of the superfine / nanocrystalline hard alloy material are improved.

The invention relates to the technical field of preparation of metal composite powder, in particular to a preparation process of tungsten-copper alloy powder, which comprises the following steps: S1, precursor compounding: performing electrochemical replacement reaction on a tungsten-containing substance and a copper-containing substance in a liquid phase to prepare a tungsten-copper composite precursor suspension; s2, freeze drying: performing spray freeze drying on the tungsten-copper composite precursor suspension to obtain fluffy porous precursor powder; and S3, reduction: performing low-temperature heat treatment on the precursor powder in a reducing atmosphere to obtain the tungsten-copper alloy powder. According to the method, copper atoms are directly subjected to reduction deposition on active sites of tungsten by utilizing the characteristic that electrochemical replacement reaction is carried out spontaneously, compounding on the atomic scale is achieved, and compared with physical mixing and surface coating of a copper plating method in the prior art, the uniformity of tungsten-copper two-phase mixing is effectively improved.

The invention discloses a hydrogen production and suspension magnetization roasting coupling device and method. The hydrogen production and suspension magnetization roasting coupling device comprises a hydrogen production device, a suspension magnetization roasting device and a coupling connection assembly. According to the device, reduction gas with carbon monoxide and hydrogen as effective components is generated through an oxidation reaction under the pressurized non-catalytic condition, hematite, limonite and siderite are converted into ferromagnetic magnetite or maghemite under the reducing agent atmosphere condition, then high-grade and high-recovery-rate iron ore concentrate is obtained through magnetic separation, and efficient utilization of resources is achieved. The process flow is short, the load is convenient to increase and decrease, the operation flexibility is high, high fusion coupling of a hydrogen production system and a hydrogen-based mineral phase conversion system is realized, the method has the characteristics of wide raw material range, low gas production cost, low carbon, environment friendliness, high heat energy recycling rate, wide application range and the like, and a new way is provided for effectively developing and utilizing refractory ore resources.