411 results about "Alumina composite" patented technology

The invention provides a preparation method of an alumina composite nickel-cobalt lithium manganate ternary material. The preparation method comprises the following steps: (1), preparing liquor A; (2), preparing liquor B; (3), installing and configuring a reaction flask; (4), adding the liquor A and the liquor B into the reaction flask to participate in hybrid reaction; (5), preparing liquor C, and adding into the flask for reaction; (6), obtaining a precursor by suction-filtering, washing and drying; and (7), mixing and roasting the precursor with a lithium source to prepare the alumina composite nickel-cobalt lithium manganate ternary material. The preparation method disclosed by the invention has the beneficial effects that firstly, liquid-phase coating is adopted, production preparation period is short, efficiency is high, and coating and dispersing are uniform; secondly, the coating layer alumina on the surface of the ternary material is a film with an amorphous structure, so that charging and discharging voltage difference is reduced, multiplying power performance and high-performance performance of the material are improved; and thirdly, characteristics of a solid-liquid phase interface among an anode material, electrolyte and a diaphragm are improved by alumina film-coating, so that velocity and efficiency of electrochemical reaction are improved.

The invention discloses a silica-alumina composite carrier and a method for preparing the same. The composite carrier is prepared from a silicon hydroxide-aluminum hydroxide gel serving as a raw material by using a super-solubility micelle method. Because the gel contains a surfactant and hydrocarbon components, silica nanoparticles and alumina nanoparticles formed after dehydration of polymerized silicon hydroxide and aluminum hydroxide still have rod-like basic structures after shaping and roasting, and the nanoparticles are disorderly stacked into a frame structure. The composite carrier has large pore volume, large aperture, high porosity, large orifices on outer surface and high pore penetrability, and particularly for high molecules, the carrier can prevent a catalyst from becoming inactivated due to blockage of the orifices, contribute to increasing the deposition of impurities and prolong the operating period of the catalyst because the carrier does not have orifices similar to ink bottle-shaped orifices. The composite carrier can be used in catalytic reactions comprising high molecular reactants or products.

Provided is the following magnetic carrier. The magnetic carrier maintains high developing performance even when the number of sheets to be output is large. Its charge-providing performance hardly reduces even when toner or an external additive is spent on the magnetic carrier. In addition, the magnetic carrier is strong in resistance against standing. The magnetic carrier includes a magnetic carrier core and a resinous coating layer formed on a surface of the magnetic carrier core, in which the resinous coating layer contains a resin composition and silica-alumina composite particles.

The invention discloses a preparation method of a carbon nanotube-alumina composite reinforced magnesium-based composite material, which relates to the manufacture of magnesium-based alloy by using a casting method. The preparation method comprises the steps of: step 1, calcining and reducing raw materials of ferric nitrate nonahydrate and alumina in the ratio of (0.07-1.00):1 to obtain an iron / alumina composite catalyst, and finally, performing catalytic pyrolysis reaction by using the mixed gas of nitrogen gas and ethylene in the volume ratio of (6-12):1 for uniformly dispersing carbon nanotubes on the surface of the alumina, so as to prepare a carbon nanotube-alumina composite reinforced phase; and step 2, adding the carbon nanotube-alumina composite reinforced phase to a molten magnesium base material, and stirring and casting to prepare the carbon nanotube-alumina composite reinforced magnesium-based composite material, wherein the added carbon nanotube-alumina composite reinforced phase accounts for 1-15% of the molten magnesium base material by mass percentage. According to the invention, the defect of a magnesium-based alloy texture in the magnesium-based composite material produced in the prior art is overcome, the excellent enhancing effect of the carbon nanotubes in a magnesium matrix can be brought into full play, and the comprehensive performance of the magnesium-based composite material is ensured to be enhanced.

Wide mesoporous alumina composites are produced by an “in situ reaction” route comprising agglomeration of an alumina powder that is capable of rehydration together with a second reactive powder such as carbonate. In one method of production, the powders are fed to a rotating forming device that is continuously sprayed with liquid under conditions to form particulates. The discharging beads are then subjected to curing and thermal activation to produce the final catalyst or adsorbent. The alumina participates in a pore altering process involving the carbonate component upon formation of hydroxycarbonate intermediates such as Dawsonite. Large fraction of the pore volume of the final product consists of wide mesopores in the 15-50 nanometers range. The alumina composites exhibit a characteristic trimodal pore structure that includes also small micro-meso pores and macropores larger than 200 nanometers.