14results about How to "Lower decomposition temperature" patented technology

The invention provides an epitaxial growth process for improving doping uniformity of n-type doped silicon carbide, and relates to the technical field of semiconductors. The method is based on a chemical vapor deposition growth technology; 11 to 20 gt; the silicon carbide epitaxial growth is carried out by taking silicon carbide with a 4-degree silicon surface in the direction as a substrate, taking trichlorosilane (TCS) and ethylene (C2H4) as growth sources and taking ammonia gas (NH3) as a doping source. Ammonia gas is adopted as an n-type dopant, the decomposition efficiency of the n-type dopant is close to 100% at the temperature of 700 DEG C or above, and the energy of N-H bond breakage of ammonia gas molecules is 390 KJ / mo which is far lower than 946 KJ / mo needed by N-N bond breakage of nitrogen molecules. Therefore, compared with a traditional doping source such as nitrogen, the ammonia gas has higher doping efficiency, residues of excessive nitrogen-containing precursors in the reaction chamber can be reduced, the memory effect is reduced, and thus more excellent in-chip uniformity and stable inter-chip repeatability of the epitaxial wafer are obtained. The selection range of the doping source is widened, the accurate control of the doping concentration is realized, and the stability of the doping concentration in the continuous growth process is improved.

The invention discloses a production method for producing low-alkalinity fluxed pellets from whole hematite limonite, which comprises the following steps: taking flue gas treatment by-product desulfurized fly ash and carbon-containing dedusting ash, feeding into a first batching bin, blanking according to a first preset proportion, feeding into a powerful mixer, mixing, and rolling at high pressure to obtain a first mixture; performing dry grinding or wet grinding on the hematite and limonite coarse powder to obtain hematite and limonite fine powder; the first mixture, hematite and limonite fine powder and bentonite are blanked according to a second preset proportion, and a second mixture is obtained; carrying out strong mixing and high-pressure roller milling on the second mixture, and pelletizing to form green pellets; and the green pellets sequentially enter a forced air drying section, an air draft drying section, a preheating section and a roasting section of a belt type roasting machine, and finally the all-hematite limonite low-alkalinity fluxed pellets are obtained. The method has the advantages that the pulverization phenomenon caused by the low bursting temperature of the drying section can be eradicated, the quality of green pellets is improved in the drying section, conditions are provided for liquid phase generation in the preheating and roasting sections, and the compressive strength of pellets is remarkably improved.

The invention relates to the technical field of silicon carbide ceramics, in particular to an in-situ induced low-temperature eutectic silicon carbide porous ceramic and a preparation method thereof. The material is prepared by mixing and sintering the following materials: silicon carbide, a synergistic sintering system, a dispersing agent, a plasticizer and water, wherein the synergistic sintering system comprises the following components: pregelatinized starch, a silicate mineral material, aluminum oxide, calcium carbonate, glass powder and rare earth oxide; the pregelatinized starch is adopted as an adhesive, the thermal decomposition behavior of the pregelatinized starch and the chemical reaction activity of the glass powder and the calcium carbonate form synergy in the process, seamless connection of the whole process from the room temperature to the sintering temperature is achieved, the sintering temperature is greatly reduced, meanwhile, the glue discharging step is omitted, and the silicon carbide porous ceramic product with good performance and few defects is obtained.

The invention relates to lightweight thermal insulation concrete and a preparation method, and relates to the field of building materials, the lightweight thermal insulation concrete comprises the following components by mass: 60-100 parts of cement, 5-10 parts of modified SEBS, 20-40 parts of fly ash, 30-60 parts of ceramsite, 0.5-1.5 parts of a compound foaming agent, 10-20 parts of a modified cellulose filler, 0.005-0.015 part of a foam stabilizer, 0.5-1.5 parts of a water reducer and 30-50 parts of water; the modified SEBS is prepared from the following raw materials: an SEBS body, itaconic acid and allyl glycidyl ether. The preparation method comprises the following steps: mixing and stirring cement, modified SEBS, fly ash and modified cellulose filler, adding ceramsite, and stirring to obtain a dry mixture; preparing a water reducing agent solution, and preparing a foaming agent dispersion liquid; adding water into the dry mixture, stirring, adding a water reducing agent solution, and stirring to obtain a wet mixture; and adding the foaming agent dispersion liquid into the wet mixture, and carrying out pressure foaming to obtain the lightweight thermal insulation concrete. The method has the effect of improving the thermal insulation performance and the anti-cracking performance of the concrete.

The invention discloses a fireproof flame-retardant plastic and a preparation method thereof, and relates to the technical field of plastics. The modified flame retardant is innovatively added into the polyolefin plastic, so that efficient flame-retardant and fireproof effects are achieved. The modified flame retardant is prepared by coating and modifying layered hydroxides with prepolymers of 1, 2-diallyl phthalate and diallylmalonic acid when ferric nitrate and chromic nitrate are subjected to coprecipitation to generate layered hydroxides, and has the effects of inhibiting smoke diffusion and blocking oxygen, so that the flame-retardant and fireproof effects are realized, and meanwhile, the flame-retardant and fireproof effects are realized. When the plastic is subjected to shrinkage or external stress caused by high temperature, the layered structure can be used as a stress dispersion center, so that the plastic can still keep relatively good mechanical properties at high temperature, and a molecular skeleton of the polymer contains a plurality of rigid benzene rings, so that the stability in a high-temperature environment can be improved, and the flame-retardant and fireproof effects of the plastic can be enhanced.

The invention belongs to the technical field of fine chemical engineering, and particularly relates to a preparation method and application of a double-alkali metal magnesium aluminate spinel catalyst. The preparation method comprises the following steps: mixing pseudo-boehmite and magnesium nitrate, adding the mixture into water, uniformly mixing, adding a dispersing agent and a precipitating agent, stirring, standing, aging, crystallizing, centrifuging, washing, drying and roasting to obtain a spinel carrier MgAl2O4; the spinel carrier MgAl2O4, a modifier and water are subjected to a reaction, hydrothermal crystallization, centrifugation, washing, drying and roasting are performed, and the treated spinel carrier MgAl2O4 is obtained; and mixing lithium nitrate, calcium nitrate, a pre-precipitating agent and water, performing ultrasonic treatment, heating, concentrating and evaporating, performing equivalent-volume impregnation on the treated spinel carrier MgAl2O4, and performing hydrothermal reaction, centrifugation, washing, drying and roasting to obtain the Li2O-CaO / MgAl2O4 double-alkali metal magnesium aluminate spinel catalyst. The preparation method is simple, and the prepared catalyst is low in cost and high in catalytic activity.

The application provides a bacillus megaterium and application of the bacillus megaterium in preparation of nano selenium organic fertilizer for increasing selenium content of tea, and belongs to the technical field of microorganisms, wherein the bacillus megaterium NT2 is preserved in China Center for Type Culture Collection, and the preservation number is CCTCC NO:M 20251806; the bacillus megaterium NT2 has strong tolerance and reduction capacity to selenium elements, can survive in high-concentration inorganic selenium, and reduce the inorganic selenium into nano selenium, and has weak capacity to enrich arsenic, cadmium and lead; can be mixed with high-temperature calcination activated high-selenium rock powder to carry out mixed fermentation, to prepare a selenium source of nano selenium organic fertilizer, to increase the selenium content of tea while ensuring that the heavy metal content does not exceed the national standard. The bacillus megaterium provided by the application can reduce the toxicity of inorganic selenium in high-selenium rock and convert it into nano selenium, and can stably, safely and standardly produce selenium-rich tea, so that the heavy metal content of tea does not exceed the standard, and the application has a broad market prospect.

This invention discloses a small-diameter, high-flow-rate microporous chemical oxygen generator and its preparation method, relating to the field of chemical oxygen generator technology. The small-diameter, high-flow-rate microporous chemical oxygen generator comprises an ignition propellant and an oxygen-generating propellant. The oxygen-generating propellant has a pit for holding the ignition propellant. The raw materials of the oxygen-generating propellant, by mass percentage, include: sodium chlorate 55%–75%, catalyst 4%–10%, chlorine inhibitor 2%–8%, metal powder 4%–10%, pore-forming component 5%–20%, kaolin 4%–10%, and water 0.5%–2%, wherein the pore-forming component includes at least one of ammonium carbonate and ammonium bicarbonate. This invention increases the combustion surface of the oxygen-generating propellant by forming micropores on its surface and inside, achieving a large flow rate of oxygen within a limited volume. Furthermore, operators can determine whether the propellant is completely dried by observing the presence or absence of odor during the drying process, thereby ensuring product uniformity and the purity of subsequent oxygen.

This invention discloses a method for preparing calcium ferrite from iron-based solid waste through low-temperature catalytic decomposition of phosphogypsum, belonging to the field of comprehensive utilization of solid waste. The method involves mixing, granulating, and roasting raw materials, including iron-based solid waste and phosphogypsum, to obtain calcium ferrite-containing sintered material. The roasting process involves feeding the material onto a belt roaster, first performing reduction roasting under a reducing atmosphere, and then performing oxidative roasting under an oxidizing atmosphere. This method fully utilizes the mineral composition characteristics of iron-based solid waste and phosphogypsum from the steel industry. By controlling the temperature and atmosphere during the high-temperature solid-phase reaction, the method achieves the directional transformation of iron and calcium components in the two industrial solid wastes into calcium ferrite-based products, while effectively removing harmful elements, resulting in high-quality calcium ferrite products.

The invention discloses a preparation method of a wood vinegar substitute, and belongs to the technical field of biomass products. The preparation method of the pyroligneous liquor substitute provided by the invention comprises the following steps: pretreating straw powder with hydrochloric acid to obtain pretreated straw powder; and mixing the pretreated straw powder, an oxidizing agent aqueous solution and water, carrying out hydrothermal reaction, separating a solid phase from a liquid phase, and repeatedly freezing and thawing the obtained liquid phase to obtain the wood vinegar substitute. The straw powder is pretreated with hydrochloric acid, the overall crystallinity of the straw powder is reduced, the content of lignin, cellulose and hemicelluloses in original straw is changed, the straw powder can be decomposed into organic acid and other target substances at a low temperature, and the straw powder can be decomposed into organic acid and other target substances by combining with the oxidizing agent. The decomposition temperature of the lignin is selectively reduced, the decomposition of the straw powder at a relatively low temperature is finally realized, and the pyroligneous liquor substitute with relatively high acid content is obtained.

This invention relates to the field of rubber additive preparation technology, and provides a microcapsule for rubber foaming agents. By weight, it comprises the following raw materials: core material: 50-80 parts chemical foaming agent, 1-5 parts dispersant, and 100-200 parts deionized water; wall material: 20-40 parts methyl methacrylate monomer, 10-30 parts ethylene-octene copolymer emulsion grafted with maleic anhydride, 0.5-2 parts initiator, and an appropriate amount of pH adjuster. The apparatus includes a premixing tank, a main reactor, a secondary reactor, a dehydration chamber, a heating tank, and a heat exchange tank, all connected in series via a diaphragm pump. By employing a double-layer composite wall material—an inner layer of rigid and tough barrier and an outer layer of flexible and compatible material—the problem of easy breakage during mixing of traditional single-layer brittle wall materials is solved. The 70°C hot water discharged from the main reactor is cooled to 50°C by the heat exchange tank and supplied to the secondary reactor, achieving cascaded utilization of thermal energy. A reversing component allows for switching between heating, water replenishment, and cleaning pipelines, resulting in a compact structure and simple operation.

The present application relates to the field of catalysts, and specifically, provides a binuclear Ru-based ammonia cracking hydrogen production catalyst and its preparation method and application. The preparation method of the binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps: S1, mixing Ru metal precursor, solvent and ligand evenly to obtain a first solution; S2, adding a carrier to the first solution, mixing evenly to obtain a second solution; S3, transferring the second solution to an autoclave, reacting at 80-180°C for 6-24 hours, the pressure of the autoclave is 0.05-0.2MPa, and obtaining a third solution; S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 6-12 hours, and then drying to obtain a sample; S5, reducing the sample at 500-550°C for 1.5-2h under an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking hydrogen production catalyst. The catalyst prepared in this application has a high ammonia conversion rate at low temperatures.

The invention discloses a method for preparing foam metal through friction stir welding, and belongs to the technical field of foam metal material preparation, and the method comprises the following steps: an alloy plate is used as a raw material, and the plate is firstly machined to form a groove for filling foaming agent powder and foaming auxiliary powder; preparing foaming agent powder and foaming auxiliary powder according to a certain proportion, and mixing the powder to prepare a powder mixture; filling the powder mixture into a groove of an alloy plate, and preparing the alloy plate filled with the mixed powder into a welding plate by adopting a friction stir welding technology; the welded plate is subjected to multi-pass rolling to form a rolled plate; compared with the prior art, the method has the advantages that porosity control and pore diameter adjustment in the foaming process are facilitated, distribution and microstructure of foaming agent mixed powder can be remarkably improved, and formation of a pore structure is facilitated.

The application provides a resourceful treatment method of sodium chloride-containing waste and polyvinyl chloride waste, and belongs to the technical field of waste treatment. The resourceful treatment method comprises the following steps: mixing sodium chloride-containing waste, polyvinyl chloride waste, a promoter and a solid halogen agent, and performing calcination treatment to obtain calcined material; mixing the calcined material with water, and performing solid-liquid separation to obtain liquid material and solid material; the solid material is recovered promoter; and the liquid material is crystallized to obtain recovered sodium chloride. The resourceful treatment method can remove organic pollutants in the sodium chloride-containing waste, effectively fix the chlorine element in the polyvinyl chloride waste, prevent the chlorine element from escaping, and reduce the harm to the environment.