2results about How to "Craft short" patented technology

The invention discloses a method for preparing a C / C-SiC composite material through multi-stage recovery of carbon / carbon composite material processing waste, and belongs to the technical field of C / C composite material preparation. The method comprises the following steps: carrying out multi-stage screening treatment on the carbon / carbon composite material processing waste, and screening and separating short carbon fibers and pyrolytic carbon powder; mixing the screened short carbon fibers and pyrolytic carbon powder with phenolic resin, industrial silicon powder and SiC powder, and preparing a fiber reinforced resin block in a mold pressing manner; and carrying out one-step continuous carbonization and ceramic heat treatment on the fiber reinforced resin block to finally obtain the C / C-SiC composite material. According to the method, high-added-value recycling of the C / C processing waste is achieved, the process is simple, the cost is low, operation is convenient and fast, the problems of resource waste and environmental pollution caused by existing waste treatment are solved, and the prepared C / C-SiC composite material is excellent in performance and can be widely applied to the fields of aerospace, high-end manufacturing and the like.

The application discloses a ruthenium-based ammonia synthesis catalyst, a preparation method thereof and application of the catalyst in catalytic synthesis of ammonia. The ruthenium-based ammonia synthesis catalyst comprises a high-entropy oxide carrier and a ruthenium active component supported on the carrier; the high-entropy oxide is a single solid solution phase formed by oxides of at least three of Mg, Ca, Sr and Ba and at least two of La, Ce, Pr, Nd and Sm. The preparation method comprises the following steps: mixing soluble salts corresponding to each metal constituting the high-entropy oxide with an organic foaming agent in water, evaporating and concentrating to form a gel, heat-treating the gel at 110-150 DEG C to make the gel foam, and obtaining a porous and fluffy solid precursor; grinding the solid precursor and performing joule heating treatment in a non-oxidizing atmosphere, instantaneously heating the solid precursor to 600-1200 DEG C within 10 seconds, keeping the temperature for 1-10 seconds, and then cooling to obtain the high-entropy oxide carrier; and supporting the ruthenium active component on the high-entropy oxide carrier to obtain the ruthenium-based ammonia synthesis catalyst.