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50 results about "Elemental impurities" patented technology

Preparation method of high-purity quartz sand

The invention discloses a preparation method of high-purity quartz sand, and belongs to the technical field of mineral refining, and the preparation method comprises the following steps: crushing: crushing quartz sand crude ore into quartz sand particles; ultrasonic scrubbing: performing ultrasonic scrubbing on quartz sand particles; magnetic separation: selecting high gradient magnetic separatorfor three times magnetic separation of quartz sand fine sand; acid leaching: performing microwave heating quartz sand after flotation, then stirring and soaking with a 10% oxalic acid solution; flotation: mixing the quartz sand after acid leaching with water and putting into a flotation machine, adjusting the pH value in three steps, and using different collectors for flotation at the same time; drying and bagging: drying in a vacuum drying oven, and vacuum bagging after cooling. The preparation process is simple, reasonable and efficient in design; iron impurities in the quartz sand can be removed by ultrasonic scrubbing, multiple magnetic separation, microwave heating and acid leaching and flotation; the iron impurities in the prepared high-purity quartz sand are reduced to below 0.35 mg/kg; and the product has stable quality and high efficiency, and is suitable for large-scale popularization and application.
Owner:SICHUAN QINGCHUAN HONGYUAN STONE IND

Method and device for circulating hydrogen repurification

The invention provides a method and a device for circulating hydrogen repurification and relates to the field of polysilicon production. According to the method and device, the circulating hydrogen is subjected to adsorption and impurity removal to reduce the content impurities of boron and phosphorus in hydrogen from 10 ppba to 0.1 ppba. The specific steps are as below: first introducing circulating hydrogen into a hydrogen cooler for cooling; cooling the hydrogen to 0 to 30 DEG C; introducing hydrogen into a first-stage adsorption reaction column to adsorb and remove impurities mainly containing boron; introducing the circulating hydrogen after the first-stage adsorption into a hydrogen cryogenic device, cooling the hydrogen to -88 to -68 DEG C; and introducing the hydrogen to a second-stage adsorption reaction column to adsorb and remove impurities mainly containing phosphorus element. According to the invention, the circulating hydrogen adsorption reaction is employed for removal of harmful impurities of boron and phosphorus elements, so as to dramatically reduce the content of impurities including boron and phosphorus in hydrogen, and upgrade the quality of circulating hydrogen. The invention makes it possible to improve Siemens method for stable production of electronic grade polysilicon, and breaks the blockade of foreign technology. The process is simple, easy to operate, and has obvious effect of impurity removal.
Owner:YICHANG CSG POLYSILICON CO LTD

Method for separating iron element impurities from secondary aluminum melt through pulse current

The invention discloses a method for separating iron element impurities from secondary aluminum melt through pulse current, and belongs to the technical field of secondary aluminum melt purification.The method comprises the following steps that the secondary aluminum alloy melt with the iron element content exceeding the standard is placed in a crucible, two electrodes and a pulse power supply are connected and inserted into the aluminum melt in parallel, pulse current is continuously applied until corresponding time, and corresponding pulse parameters are selected according to the volume andthe temperature of the melt, wherein the pulse current treatment parameter range comprises the parameters that the frequency is 20 - 50kHz, the voltage is 1 - 100V, the current density is 0.1 - 700A/cm<2>, and the action time is 1 - 10h. According to the method, an Al element and a Fe element in the melt are subjected to electromigration in different directions under the action of the pulse current, so that the Al element and the Fe element are enriched at the positive electrode and the negative electrode respectively, and the purpose of purifying the aluminum melt is achieved; according tothe method for separating the iron element impurities from the secondary aluminum melt through the pulse current, the aluminum melt can be subjected to pulse current treatment under the condition thatno neutralizing element is added to pollute the melt, the iron impurity elements in the aluminum melt are separated, and the melt is purified; and the method is easy to operate, efficient and free ofpollution, the iron removal efficiency is greatly improved, and the requirement of current industrial green development planning is met.
Owner:UNIV OF SCI & TECH BEIJING

Apparatus and method for preparing high-purity lithium fluoride

The invention discloses an apparatus for preparing high-purity lithium fluoride, wherein the apparatus comprises a reaction kettle, a condensation reflux device, a grinding device and a tail gas absorption device. The invention further provides a method for preparing high-purity lithium fluoride, wherein the method comprises: 1) carrying out a mixing reaction on lithium carbonate solid particles and a hydrofluoric acid liquid in a reaction kettle to form a lithium fluoride-hydrofluoric acid-lithium carbonate mixed slurry, hydrogen fluoride and carbon dioxide gas; 2) conveying the lithium fluoride-hydrofluoric acid-lithium carbonate mixed slurry to a grinding device, and grinding; and 3) conveying the grinded mixed slurry to the reaction kettle, continuously carrying out a reaction, makingthe hydrogen fluoride and the carbon dioxide gas generated by the reaction enter a condensation reflux device, and carrying out condensation reflux on the hydrogen fluoride. According to the present invention, with the apparatus and the method, the reaction process can be completely carried out, the problem of separation of carbon dioxide from hydrogen fluoride in the tail gas of the lithium fluoride synthesis process is solved, no other elemental impurities are introduced during the reaction, and the obtained lithium fluoride has high purity.
Owner:GUIZHOU INST OF TECH +1

Purifying method of aluminum nitride powder, aluminum nitride powder prepared by method and application of aluminum nitride powder

InactiveCN110697665AHigh purityPromote sintering synthesisNitrogen compoundsCarbon impuritiesAluminium powder
The invention relates to a purifying method of aluminum nitride powder, and the method comprises the following steps: (1) putting an aluminum nitride powder raw material containing carbon impurities into a container, putting the container into a sintering furnace, and vacuumizing to discharge impurity gas in the furnace; and (2) introducing carbon dioxide gas into the sintering furnace, and then performing sintering treatment to obtain the aluminum nitride powder. The invention also relates to the aluminum nitride powder prepared by the method and application of the aluminum nitride powder inpreparation of aluminum nitride ceramics. The method breaks through the limitation of the traditional carbon discharge process; new oxygen element impurities are not introduced, carbon impurities which are not completely reacted in the nitridation reaction are removed, and the high-purity aluminum nitride powder can be obtained; the high-purity aluminum nitride powder can effectively promote sintering synthesis of aluminum nitride ceramic and finally effectively improve the performance such as the heat conductivity of an aluminum nitride ceramic product, and therefore the high-purity aluminumnitride powder has wide application prospects in the field of manufacturing of heat dissipation substrates and circuit substrates, especially large-scale integrated circuit substrates.
Owner:AEROSPACE INST OF ADVANCED MATERIALS & PROCESSING TECH

Method for preparing boron carbide powder by adopting organic carbon source

The invention provides a method for preparing boron carbide powder by adopting an organic carbon source. The method comprises the following steps: respectively dissolving zinc nitrate hexahydrate and dimethylimidazole in a solvent methanol; respectively heating the solutions, and continuously performing magnetic stirring; pouring the zinc nitrate hexahydrate solution into the dimethylimidazole solution, and performing mixing and standing; carrying out centrifugal separation to obtain a ZIF-8 white precipitate, washing the white precipitate with methanol, drying the washed ZIF-8 powder, and performing grinding; performing pyrolysis in an argon atmosphere to obtain nano-porous carbon; dissolving boric acid H3BO3 and nano porous carbon in deionized water, carrying out ultrasonic dispersion, then carrying out rotary evaporation, drying in a drying oven, performing grinding, and performing sieving with a 100-mesh sieve; and performing calcining to obtain boron carbide. According to the preparation method disclosed by the invention, the NPC which does not contain Zn element impurities and can retain uniform particle size and an ordered nanopore structure can be obtained by optimizing a pyrolysis process of the ZIF-8 powder, such as pyrolysis temperature and heat preservation time.
Owner:JINGDEZHEN CERAMIC INSTITUTE

Method for detecting element impurities in tigecycline for injection

The invention provides a method for detecting element impurities in tigecycline for injection. The detection method comprises the following steps: preparing a linear standard solution of each elementimpurity; preparing an internal standard solution; preparing a sample to be detected, redissolving tigecycline for injection with purified water to form an aqueous solution, and mixing the aqueous solution with a diluent to form a to-be-detected sample, wherein the diluent is a mixed solution of HNO3, purified water and a gold standard solution in a volume ratio of (1-3): (97-99): 0.02, and the concentration of the gold standard solution is 1000 [mu] g/mL; drawing a standard curve; sample detection: mixing the to-be-detected sample and the internal standard solution, introducing the sample anddetecting by using an inductively coupled plasma mass spectrometer to obtain the response values of each element; and converting to obtain the impurities of each element in tigecycline for injectionaccording to the response value obtained by sample detection and the standard curve. The diluent ensures the dissolution performance of the element impurities so that the content of the impurities ofeach element can be detected by one method.
Owner:瀚晖制药有限公司

A high-strength and toughness cast aluminum-silicon alloy and its preparation method and application

Provided in the present invention are a high strength and ductility casted aluminum-silicon alloy, a manufacturing method for same, and applications thereof. The aluminum-silicon alloy consists of the following components in terms of mass percent: Si 7-8%, Mg 0.4-0.5%, Fe 0.1-0.2%, Ti 0.1-0.2%, Sr 0.01-0.02%, La 0.03-0.06%, Ce 0.02-0.04%, and the remainder is Al and unavoidable elemental impurities. The manufacturing method comprises the smelting of an aluminum-silicon alloy liquid, refinement and modification, refining for gas removal and impurity removal, casting, and a solution ageing treatment. The present invention, by optimizing the content of elemental Si and Mg, refining and modifying an α-Al crystallite, a β-Fe iron-rich phase, and an eutectic Si phase, allows the α-Al dendritic crystal to be converted into fine equiaxed crystallites, allows the acicular and flaky β-Fe iron-rich phase and the eutectic Si phase to be converted into a fine granular or short rod form, and eliminates the hazards posed by the acicular and flaky β-Fe iron-rich phase and the eutectic Si phase on the strength, plasticity, and fracture toughness of the aluminum-silicon alloy. The casted aluminum-silicon alloy of the present invention is provided with high strength, great plasticity, and excellent fracture toughness and is applicable in casting various force-bearing structural parts, such as vehicular lightweight structural parts.
Owner:GUANGDONG INST OF NEW MATERIALS

A method for separating iron element impurities by pulse current in recycled aluminum melt

The invention relates to a method for separating impurities of iron element by pulse current in recycled aluminum melt, which belongs to the technical field of purification of recycled aluminum melt. Place the secondary aluminum alloy melt with excessive iron content in the crucible, connect the two electrodes with the pulse power supply and insert them into the aluminum melt in parallel, continue to apply the pulse current until the corresponding time, and select the corresponding pulse according to the volume and temperature of the melt parameter. Pulse current processing parameter range: frequency 20~50kHz, voltage 1~100V, current density 0.1~700A / cm 2 , Action time 1min ~ 10h. The method utilizes the electromigration of Al elements and Fe elements in the melt in different directions under the action of a pulse current to enrich them at the positive electrode and the negative electrode respectively, so as to achieve the purpose of purifying the aluminum melt. The invention can carry out pulse current treatment on the aluminum melt without adding any neutralizing element to pollute the melt, so as to realize the separation of iron impurity elements in the aluminum melt and purify the melt. The method is simple, efficient, and pollution-free, greatly improves the efficiency of iron removal, and meets the requirements of the current industrial green development plan.
Owner:UNIV OF SCI & TECH BEIJING

Semiconductor substrate structure and manufacturing method thereof

The invention relates to the technical field of semiconductor integrated circuit manufacturing, in particular to a semiconductor substrate structure comprising an N-type buried layer and a manufacturing method of the semiconductor substrate structure. The base structure comprises a P-type substrate layer, wherein N-type element impurities are doped into a buried layer region in the P-type substrate layer to form an N-type buried layer; a P-type epitaxial layer which is deposited on the P-type substrate layer, wherein the concentration of P-type impurities in the P-type epitaxial layer is a second concentration; a P-type epitaxial barrier layer is formed between the P-type substrate layer and the P-type epitaxial layer, wherein the P-type epitaxial barrier layer is used for preventing N-type element impurities from evaporating into the P-type substrate layer from the N-type buried layer; the P-type impurity concentration of the P-type epitaxial barrier layer is a first concentration; the first concentration of the P-type impurities in the P-type epitaxial barrier layer is greater than the second concentration of the P-type impurities in the P-type epitaxial barrier layer. The methodis used for manufacturing the substrate structure. According to the invention, the problem that the P-type epitaxial layer is neutralized and even inverted when the bipolar NPN transistor is manufactured in the prior art can be solved.
Owner:HUA HONG SEMICON WUXI LTD
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