32 results about "Cryptocrystalline" patented technology

The invention relates to the technical field of nanometer preparation, in particular to a method for peeling off graphite to obtain graphene based on a shear force machine. The method comprises the specific steps that 5-1*10<9> mg of one or more of massive crystalline graphite, crystalline flake graphite, cryptocrystalline graphite, expanded graphite and highly oriented pyrolytic graphite are weighed, 50-5*10<6> mL of water and a mixing solvent with 10 or smaller carbon atom alcohol are added, the uniformly-mixed solution is placed into the shear force machine for performing peeling for 0.3-120 h, standing is performed, the centrifuging speed is 100-10000 rpm / min, and post-treatment is performed, so that graphene is obtained. The preparation method is mild in condition, the reaction is green, adopted raw materials and solvents are simple, no liquid waste pollution exists, large-scale preparation can be performed, and the method has the application prospect for producing graphene.

The invention discloses a lithium ion battery cathode material and a preparation method thereof, which lower the cost of the lithium ion battery cathode material and improve the high-energy density thereof. The lithium ion battery cathode material takes more than one of natural crystalline graphite, natural cryptocrystalline graphite and natural crystalline vein graphite as matrixes, a non-graphitic carbon material is coated outside the matrixes, and the coated particles are compounded with a conductive material. The preparation method of the lithium ion battery cathode material comprises thefollowing steps of mixing and drying a liquid phase, carbonizing, carrying out high-temperature treatment and compounding. Compared with the prior art, the graphite with lower carbon content is takenas a raw material to greatly reduce the raw material cost; by adopting a hot air drying mode, the preparation process is simplified and a coating layer is more solid and compact; and by adopting lower carburizing temperature and the temperature for high-temperature heat treatment, energy consumption is reduced, and product cost is further lowered.

The invention discloses a soil improvement agent suitable for grounding works in high soil resistivity environments, which comprises the following components in percentage by weight: 14-18wt% of modified starch super absorbent resin with the molecular weight of 20,000-40,000, 42-52wt% of 150-200 meshed cryptocrystalline graphite powder, 26-38wt% of calcium-magnesium-based soil gelling agent (calcium-magnesium-based bentonite), 2-4wt% of calcium-aluminum-based soil affinity agent (calcium-aluminum hydroxide mixture), 1-3wt% of soil blowing agent (sodium silicate), 1-3wt% of zinc metal preservative, and 1-3wt% of lanthanide rare earth metal slag. The soil improvement agent disclosed by the invention utilizes the water absorption characteristic of the super absorbent resin to achieve the purpose of preservation of soil moisture, utilizes the electrical conductivity of the graphite material to reduce the contact resistance between the metal conductors and soil, adds a soil gelling agent and other components to result in a more compact and stable transition conducting layer, adds the lanthanide rare earth metal slag to enhance the electrical conductivity, and adds the zinc metal preservative to prolong the service life. The soil improvement agent is especially suitable for soil improvement in geological environments with high soil resistivity and extremely-droughty geological environments.

The invention discloses a method for purifying aphanitic graphite flotation concentrate. The method includes steps of (1), removing reagents by means of ultra-fine grinding; (2), carrying out two-section heating rinsing and concentrating on the aphanitic graphite flotation concentrate; (3), soaking the aphanitic graphite flotation concentrate in acid at the constant temperatures of 90 DEG C for 1 hour; (4), removing impurities by means of reverse flotation. The method has the advantages that the aphanitic graphite flotation concentrate with the carbon (C) content of 85-90% is used as a raw material and is treated by the aid of processes for 'removing the reagents by means of ultra-fine grinding, carrying out the two-section heating rinsing and concentrating, soaking the aphanitic graphite flotation concentrate at the constant temperatures of 90 DEG C for 1 hour and removing the impurities by means of reverse flotation' for characteristics of small particle sizes of graphite crystals in the aphanitic graphite flotation concentrate, stable properties at the normal temperatures, good inherent flotability, the residual flotation reagents on the surfaces of minerals and the like, and accordingly high-purity graphite concentrate with the carbon (C) content higher than 99% can be obtained.

The invention discloses steel for a bearing ring of a large-size shield tunneling machine and a heat treatment method thereof. The steel consists of the following elements in percentage by weight: 0.41-0.45 percent of C, 0.17-0.37 percent of Si, 0.60-0.80 percent of Mn, 0.90-1.20 percent of Cr, 0.15-0.25 percent of Mo, 0.50-0.70 percent of Ni, less than or equal to 0.015 percent of P, less than or equal to 0.003 percent of S, less than or equal to 0.00018 percent of H, less than or equal to 0.0015 percent of O and the balance of Fe and normal impurities. The experiment steel subjected to alloying design has good hardenability, the hardening layer depth can be over 40mm in the end quenching experiment and is 30mm higher than that of 42CrMo; the bearing ring of the large-size shield tunneling machine is wholly subjected to quenched-tempered heat treatment, and after the surface is subjected to induction hardening, the surface hardening layer texture is cryptocrystalline martensite, and the matrix structure is tempered sorbite; the surface has high hardness and has the average value of 58.5-60.3HRC; the core has good toughness, the impact toughness AKv value at the temperature of 20 DEG C below zero is over 106J; and the steel has proper hardness, and the average value of the hardness is 272-283HB. Meanwhile, a control process window of an actual production cooling medium is wide, and the cooling speed is over 10 DEG C per second. Therefore, the requirement on the comprehensive mechanical property of the steel for the bearing ring of the large-size shield tunneling machine can be met.