39results about How to "Meet high purity requirements" patented technology

The invention discloses cotton pulp for electrolytic capacitor paper. The cotton pulp has the following indexes: the degree of polymerization is 900-950; the electrolyte absorbability is guaranteed while the necessary mechanical strength is guaranteed, and the electric conductivity is smaller than or equal to 1.5 ms / m; the content of water-soluble chloride is smaller than or equal to 10 ppm; the ash content is smaller than 0.08%; the content of iron is smaller than or equal to 10 ppm; the requirement for high purity of an electrolytic capacitor is met, influence of impurities on performance of an electrolyte and electrode foil is eliminated, and the high purity is the main mark for differing the electrolytic capacitor paper from other paper. The invention further discloses a technology of the cotton pulp. The technology comprises a step of early processing of cotton linter and a step of late processing.

The invention discloses a preparation method of high-purity zinc phosphide, comprising the following steps: 1) quartz tube pretreatment, 2) batching, 3) tube sealing, 4) high-temperature synthesis, 5) product treatment, the invention uses high-purity phosphorus and high-purity Zinc direct conversion and production of high-purity zinc phosphide, the main reaction process occurs after the temperature reaches the melting point of zinc, actually belongs to the reaction between steam, belongs to the direct synthesis of elements, the requirements for the form of raw materials are not very strict, and the raw materials have not been processed , to meet the requirements of high purity, the present invention controls the internal pressure of the tube through temperature control operations such as slow temperature rise, constant temperature, and slow temperature drop, and distributes the length of the heating area and condensation area of ​​the synthetic quartz tube to successfully control the phosphorus vapor pressure in the quartz tube to achieve a large amount of The safe synthesis of zinc phosphide; through the control of the length of the condensation area and the heating area, a higher yield of the product is achieved. The product is used in the application fields of optoelectronic device production, diffusion source, and nanomaterials.

The invention discloses a nitrogen control method for carburizing gear steel. The nitrogen control method comprises the steps of converter smelting, LF ladle refining, VD vacuum refining and continuous casting. In the present invention, the molten steel in the ladle is softly blown after the converter is tapped, the manganese nitride alloy is added to the molten steel during the soft blowing process, and nitrogen is blown into the molten steel during the refining process of the LF ladle, so as to effectively improve the content of the molten steel in the molten steel. Nitrogen content; degassing and de-inclusion during VD vacuum refining. The nitrogen control method of the carburized gear steel of the present invention can realize precise control of the nitrogen content in the carburized gear steel, so as to have a better effect of refining grains. The high cleanliness of the carburized gear steel is realized, and the cleanliness requirements are met; the nitrogen control method of the present invention can be realized by simply improving the preparation process of the existing carburized gear steel, and has the advantages of low cost of process improvement and easy popularization. Advantage.

The invention discloses a preparation method of high-purity micron-sized spherical silica micropowder. The preparation method comprises the following steps: firstly, providing a precursor solution containing silicon; secondly, adding the precursor solution into an oil phase containing an emulsifier and then stirring to obtain a mixed solution; thirdly, adding a basic catalyst into the mixed solution, standing and ageing, washing precipitate with a mixture of a solvent and water, and then drying to obtain silica microspheres, wherein the precursor solution containing the silicon is one or a mixture of two or more of Si(OR)4, ethyl silicate 40, ethyl silicate 32 and SiR2(OR1)3, and R, R1 and R2 are C1-3 alkyl groups which are independent of one another. The silica microspheres disclosed by the invention have the advantages that the purity is excessively-high and the contents of all metal impurities are below 0.2 ppm; in addition, the preparation method disclosed by the invention is easy to operate and products in the preparation process are easy to treat; and particle sizes of the finally-obtained silica microspheres are 0.3 to 0.4 [mu]m.

The invention discloses a purification method of isopropyl alcohol for a liquid chromatography-mass spectrometer. The method is characterized in that impurities in a raw material isopropyl alcohol are removed through processes such as modified active carbon adsorption and the like so as to obtain isopropyl alcohol for a liquid chromatography-mass spectrometer. By the purification method of isopropyl alcohol for a liquid chromatography-mass spectrometer, isopropyl alcohol with purity being greater than or equal to 99.99 wt% can be obtained. The method meets high-purity requirement of a liquid chromatography-mass spectrometer. Therefore, isopropyl alcohol obtained after purification can be applied in the field of liquid chromatography-mass spectrometers, and the application range of isopropyl alcohol is broadened.

The invention provides a low thermal conductivity gold material, a preparation method thereof, and a gold utensil. The low thermal conductivity gold material includes elemental Au, Q and elemental V, wherein Q includes elemental Ti and / or elemental Cr, and the weight content of elemental Au is ≥ 99.99%. On the one hand, the weight content of elemental Au is more than or equal to 99.99%, and the material gold has a high purity, which meets the high purity requirements of precious metal products. On the other hand, the material also includes elemental Q and elemental V, as smaller doping element components, which promotes better low thermal conductivity of the material. At the same time, the mechanical properties of the material, such as hardness, are better, and the use effect is better.

The invention discloses a synthesis method for bromoacetaldehyde diethyl acetal. The synthesis method for bromoacetaldehyde diethyl acetal is composed of the following process steps: (1) catalytic bromination reaction: stirring and dissolving raw materials, namely paracetaldehyde, a copper catalyst, concentrated sulphuric acid and absolute ethyl alcohol, cooling by an ice-salt bath, then slowly dropwise adding elementary-substance bromine in a reaction kettle, and reacting for 1-1.5 hours at minus 5-0 DEG C to obtain the ethanol solution of bromoacetaldehyde; (2) acetalation reaction: pouring an inorganic dehydrant in the ethanol solution of bromoacetaldehyde, which is obtained in the last step, heating to 35-40 DEG C, reacting for 5-6 hours while preserving heat, then adding ice water, reacting for 15-20 minutes, adding sodium carbonate to neutralize the reaction solution, stirring, standing to layer, separating out an organic layer, extracting a water layer by dichloroethane twice, mixing organic phases, carrying out reduced pressure distillation to recover a solvent, then carrying out reduced pressure distillation, and collecting fractions at 65-68 DEG C to obtain high-purity bromoacetaldehyde diethyl acetal. The synthesis method for bromoacetaldehyde diethyl acetal disclosed by the invention is available in raw materials, few in reaction steps, low in cost, high in product purity, and stable in quality.