5 results about "Calcium silicide" patented technology

The invention belongs to the field of smelting, and particularly relates to a smelting method for improving cleanliness of austenitic stainless steel. The method comprises the following steps: melting raw materials in an electric furnace, and tapping; carrying out AOD (argon oxygen decarburization) refining; and LF refining. The method comprises the following steps: controlling the contents of C and Si elements and the tapping temperature during tapping of molten raw materials in an electric furnace; the temperature of molten steel obtained through AOD refining is set, FeSi is used for primary reduction, the content of Si is controlled, reduction slag lime and fluorite are added for slagging in secondary reduction, the target requirement for alkalinity of reduction slag is controlled, aluminum particles are added, and the rest is reduced through calcium silicate blocks; in the LF refining process, CaSi powder is adopted for diffusion deoxidation, Al deoxidation is not used, the oxygen target is controlled, the white slag retention time is controlled, the argon feeding stirring time and the soft argon blowing time are controlled, and crane ladle pouring is carried out, so that the inclusion requirement of the current high-end 304 austenitic stainless steel can be met, and the inclusion is reduced to be smaller than or equal to 1.0 grade from the 1.5 grade or 2.0 grade.

The invention discloses a preparation method and application of a siloxyalkene-graphene composite aerogel for in-situ generation of silicon nitride, and belongs to the technical field of composite material preparation technologies and electrochemical energy storage materials. The method comprises the following steps: reacting purified calcium silicide with concentrated hydrochloric acid, washing, drying, and carrying out ultrasonic stripping to obtain silylene; dispersing the composite aerogel and graphene oxide, directionally freezing by liquid nitrogen, and freeze-drying to obtain composite aerogel; and carrying out heat treatment in an argon / ammonia gas atmosphere, and generating silicon nitride on the surface of the silylene in situ. According to the method, uniform compounding of silicon nitride and controllable construction of a three-dimensional porous structure are realized on the basis of topological chemical conversion and directional freezing technologies. The silicon nitride content in the obtained composite aerogel is 10-40%, and the composite aerogel has excellent structural stability and conductive network, can provide reversible capacity of 500-1000 mAh / g under 1.5 C multiplying power when being used as a lithium ion battery negative electrode material, and has good application prospects in the field of energy storage.

The application discloses a silicon-based solid high-density hydrogen storage material, a synthesis method and a hydrogen adsorption silicon method, wherein the synthesis method of the silicon-based solid high-density hydrogen storage material comprises the following steps: taking silicon chip cutting discarded silicon dust powder / silicon mud as a basic raw material, and obtaining silicon micro powder with nanometer size after cleaning and drying; the purity of the silicon micro powder is set to be 4.8N or more, the size is 50-200nm, and D50=80-130nm; the silicon micro powder is synthesized with calcium metal to form layered calcium silicide, specifically, the silicon micro powder is synthesized with calcium micro powder to form layered calcium silicide, then calcium ions existing between the layered calcium silicide layers are removed, and layered siliconene is obtained, and the density of the layered siliconene is 1.5g / cm 3 The silicon-based solid high-density hydrogen storage material, the synthesis method and the hydrogen adsorption silicon method provided by the application modify the basic crystal lattice structure of silicon material into a layered stacked siliconene structure, form a quasi-two-dimensional substance arranged in a honeycomb lattice plane, and have a wave mesoscopic / microscopic structure, and a large amount of hydrogen atoms can be adsorbed between the layers.

The invention discloses a silicon-based solid-state high-density hydrogen storage material, a synthesis method and a method for adsorbing silicon by hydrogen, and the synthesis method of the silicon-based solid-state high-density hydrogen storage material comprises the following steps: taking silicon chip powder / silicon sludge abandoned by cutting a silicon wafer as a basic raw material, cleaning and drying to obtain nano-sized silicon micro-powder; the purity of the silica powder is set to be 4.8 N or above, the size is 50-200 nm, and D50 is equal to 80-130 nm; the method comprises the following steps: synthesizing lamellar calcium silicide from silica powder and calcium metal, specifically synthesizing lamellar calcium silicide from silica powder and calcium powder, and then removing calcium ions existing between lamellar calcium silicide layers to obtain lamellar silylene with the density of 1.5 g / cm < 3 >. According to the silicon-based solid-state high-density hydrogen storage material, the synthesis method and the method for adsorbing silicon by hydrogen, a basic lattice structure of a silicon material is modified into a layered stacked silylene structure, a quasi-two-dimensional substance in honeycomb lattice plane arrangement is formed, the quasi-two-dimensional substance has a wave mesoscopic / microstructure, and a large number of hydrogen atoms can be adsorbed between layers of the quasi-two-dimensional substance.

The present application relates to the technical field of material preparation, and particularly relates to a preparation method of silicene / graphene composite material, which comprises the following steps: adding calcium silicide into acetonitrile, stirring to uniformly disperse the calcium silicide in the acetonitrile solution, then adding acetonitrile solution of transition metal inorganic salt into the solution under continuous stirring, filtering and collecting the sample after stirring for one to two weeks, washing the sample with acetonitrile for several times, and fully drying the obtained product to obtain the silicene; placing the prepared silicene in a tube furnace, heating the silicene to 500 DEG C at a rate of 5 DEG C / min under the mixed atmosphere of acetylene and argon, keeping the temperature for 2h, and naturally cooling to obtain the silicene / graphene composite material. The present application utilizes the weak oxidizability of transition metal ions, topologically converts the calcium silicide into silicene through the original site replacement reaction, further takes the metal element produced in the replacement reaction as a catalyst, and converts acetylene into graphene under heating condition, so that the preparation process of the silicene / graphene composite material is simplified.