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215results about How to "Low impurity content" patented technology

Foundry waste sand regeneration and reuse method and device

A foundry waste sand regeneration and reuse method comprises the following steps: pretreatment of waste sand: the original waste sand is removed with waste garbage through a closed grid unloader, removed with waste iron through a suspension type magnetic separator, removed with large-particle waste sand through a linear vibrating screen, and removed with waste scrap ions through a cut-through magnetic separator, and then enters a waste sand storage tank for storage; cleaning of waste sand: the pretreated waste sand is conveyed to a cleaning area through a sand pump, is introduced to the sand-water separator to remove part of water, then enters a scrubbing-cleaning combined tank for scrubbing and cleaning, enters a buffering concentration tank for sedimentation and concentration, and finally enters a dewatering screen to get rid of part of the water; drying: after the above processing, the waste sand is subjected to low-temperature drying or high-temperature roasting to obtain reclaimed sand, then the reclaimed sand is put into a regeneration sand tank for storage; lamination of regenerated sand: the measured regenerated sand is heated to a certain temperature through a heater, and is put into a precoated sand blender together with adhesive to mix evenly, then the mixture is cooled to room temperature to obtain the precoated sand, and the precoated sand is put into a bucket for storing finished sand.
Owner:广西兰科资源再生利用有限公司

Method for extracting high-purity steviol glycosides from stevia rebaudiana

The invention relates to a method for extracting high-purity steviol glycosides from stevia rebaudiana. The method comprises the following steps: (1) soaking a ground stevia rebaudiana raw material into water, and adding a cellulase preparation for enzymolysis; (2) carrying out heating extraction and centrifugation, and filtering, so as to obtain stevia rebaudiana enzyme extraction liquid; (3) carrying out water-bath heating on the stevia rebaudiana enzyme extraction liquid, adding an inorganic salt flocculating agent, stirring, flocculating, carrying out centrifugation, and filtering, so as to obtain stevia rebaudiana edulcorated liquid; (4) carrying out decolorization adsorption on the stevia rebaudiana edulcorated liquid by virtue of a macroporous adsorption resin column, carrying out elution through eluent, carrying out nanofiltration, and concentrating, so as to obtain a stevia rebaudiana concentrated liquid; and (5) carrying out silica-gel column chromatography and elution on the stevia rebaudiana concentrated liquid, collecting each fraction, concentrating, and drying, so as to obtain multiple high-purity steviol glycosides products. The purity of the products obtained by virtue of the method can reach up to 98.4%, and the final yield is more than 90%; the residual amounts of ethanol and ethyl ester are low, so that the method is environmentally friendly and safe; the method is simple in process, high in operability, low in energy consumption and cost and applicable to industrial production.
Owner:HUNAN HUACHENG BIOTECH

Preparing method for ball-like metal magnetically soft alloy powder

The invention relates to a preparing method for ball-like metal magnetically soft alloy powder, and belongs to the technical field of powder preparing. The method comprises the steps that raw materials of a metal magnetically soft alloy are weighed and mixed according to the weight ratio, intermediate-frequency induction smelting is adopted, and the molten alloy is prepared into an alloy casting strip through a thin-strip continuous casting technology; the alloy casting strip is placed into a crushing device, and the alloy casting strip is crushed into particle powder under the inert gas shielding condition; the crushed powder is placed into a shaping treatment device to be shaped, ball-like powder with the regular shape is obtained, the powder is subjected to annealing heat treatment, and fine powder is prepared through screening and collecting. According to the method, the uniformity of alloy powder components can be obviously improved, meanwhile, the powder wrapping insulating and pressing forming are facilitated through the prepared ball-like single-crystal particle powder, the uniformity degree of a soft magnetism powder core pressing insulating layer and the mechanical strength obtained after pressing forming can be obviously improved, the probability of damage of the insulating layer in the powder pressing forming process is greatly reduced, and accordingly the application field of the soft magnetism powder core is greatly enlarged.
Owner:有研增材技术有限公司

Preparation method for high-purity high-softening-point asphalt

ActiveCN105567275AHigh purityLow impurity contentWorking-up pitch/asphalt/bitumen by distillationWorking-up pitch/asphalt/bitumen by chemical meansQuinolineEvaporator
The invention relates to a preparation method for high-purity high-softening-point asphalt. The preparation method includes (1), adding low-QI high-purity impregnant asphalt into a stirring reaction kettle, continuously injecting air and nitrogen, stirring the asphalt, and performing air oxidation at the temperature of 180-330 DEG C for 10-30 hours; (2), adding the oxidized asphalt obtained from the step (1) into a scrapper film evaporator, and performing film distillation with the presence of nitrogen at the temperature of 320-360 DEG C under the vacuum negative pressure of 0.02MPa to remove light components to obtain the high-purity high-softening-point asphalt. The preparation method has the advantages that the softening point of the obtained high-purity high-softening-point asphalt reaches 250-300 DEG C, the coking value is larger than or equal to 75%, quinoline insoluble is less than or equal to 28%, volatiles are less than or equal to 36%, and toluene insoluble is more than or equal to 58%; impurity content is low, purity is high, production process is simple, energy conservation and environment protection are achieved, and the preparation method can be widely applied to lithium ion battery cathode material coating and carbon fiber production.
Owner:JINING CARBON GRP CO LTD +1

Method for producing feed-grade wet-process purified phosphoric acid and high-purity high-whiteness semi-hydrated gypsum

The invention discloses a method for producing feed-grade wet-process purified phosphoric acid together with high-purity high-whiteness semi-hydrated gypsum. The method includes following steps: subjecting raw phosphorite to smashing, grinding and flotation to obtain concentrate pulp, adding a metal ion inhibitor into the concentrate pulp, and filtering and separating after reaction to obtain pretreated phosphorite pulp; enabling phosphoric acid and the pretreated phosphorite pulp to be in extraction decomposition reaction, adding a compound purifying agent for defluorination and dearsenification, filtering and separating mixed pulp after reaction to obtain a filter cake I and filtrate I, adding monocalcium phosphate crystallization improver into the filtrate I for monocalcium phosphate cooling crystallization, filtering and separating to obtain crystallized monocalcium phosphate and filtrate II, enabling crystallized monocalcium phosphate and concentrated phosphoric acid to be in secondary extraction reaction, filtering and separating to obtain filtrate-the wet-process phosphoric acid, using hot water to wash the filter cake, and drying the filter cake to obtain semi-hydrated gypsum. By the method, concentration of the wet-process phosphoric acid is increased, impurity content is lowered, and the feed-grade wet-process phosphoric acid and high-purity high-whiteness semi-hydrated gypsum can be obtained.
Owner:SINOCHEM YUNLONG

Method for preparing mullite and co-producing polyaluminum chloride by using high-alumina fly ash

The invention provides a method for preparing mullite and co-producing polyaluminum chloride by using high-alumina fly ash. The method comprises the steps: activating the high-alumina fly ash in concentrated hydrochloric acid, carrying out liquid-solid separation, and carrying out washing, so as to obtain first washed solid and first washing liquid; subjecting the first washed solid to a desilicification reaction in a concentrated base solution, carrying out liquid-solid separation, and carrying out washing, so as to obtain second washed solid and second washing liquid; washing the second washed solid in dilute hydrochloric acid, carrying out liquid-solid separation so as to obtain third solid and third washing liquid, and washing the third solid by water, so as to obtain fourth solid and fourth washing liquid; carrying out aftertreatment on the fourth solid so as to obtain the mullite, and preparing the polyaluminum chloride from the first washing liquid and/or the third washing liquid. The mullite prepared by the method is low in impurity content, high in bulk density and low in water absorption rate, the polyaluminum chloride flocculant can be coproduced, the source of raw materials is wide, the process is simple, and the acid/base consumption is low, so that the method has good economic, social and environmental benefits.
Owner:INST OF PROCESS ENG CHINESE ACAD OF SCI

Three-way copper catalyst applied to synthesizing organic silicon monomer and preparation method thereof

The invention discloses a three-way copper catalyst applied to synthesizing organic silicon monomer and a preparation method of the three-way copper catalyst. The preparation method comprises the following steps of: crushing copper oxide to be with a granularity of 1-10 micrometers; using hydrogen and nitrogen decomposed by ammonia as reducing gases to reduce the copper oxide in a reduction furnace with the temperature of 200-450 DEG C into metal copper powder; filling the reduced metal copper powder into a fluidized bed, introducing an oxygen-nitrogen mixture with an oxygen pressure not more than 0.015 MPa through the bed bottom to oxidize the metal copper at the temperature of 100-250 DEG C for 2-7 hours, thus obtaining copper catalyst product including cuprous oxide, metal copper and copper oxide, wherein the copper catalyst product comprises the following components in percentage by weight: 20-40% of cuprous oxide, 40-80% of metal copper and 1-12% of copper oxide. According to the preparation method, the employed copper oxide material is low in impurity content, impurities are not introduced in the synthesis of organic silicon monomer, requirement on reaction equipment in the preparation process is simple, three wastes (waste gas, waste water and waste residues) are not generated in the process, and a mass of holes are generated due to the departure of oxygen after the copper oxide is employed to carry out reduction, so that the activity and selectivity of the catalyst are improved.
Owner:JINCHUAN GROUP LIMITED

Method for extracting beryllium from alexandrite-type beryllium concentrate with low enrichment ratio

The invention discloses a method for extracting beryllium from alexandrite-type beryllium concentrate with a low enrichment ratio, and aims to solve the problem of high impurity concentration in the leachate when alexandrite-type beryllium mineral is soaked in acid directly, which strongly influences the follow-up recycling of beryllium. The method comprises the procedures of concentrate pre-treatment, acidification and roasting, water immersion, impurity removing, extraction, and recycling. The method comprises the following particular steps: pretreating the beryllium concentrate using a hydrochloric acid solution 3-5 mol/L with the concentration of 3-5 mol/L; adding concentrated sulfuric acid into the pretreating material obtained in the step (1) according to the acid mineral ratio of 1:(0.8-1.2); performing acidification and roasting for 0.5-1.5 h; performing water immersion according to the liquid solid ratio of (2-3):1; removing impurity through coprecipitation; extracting; performing reextraction, adopting stripping agent with the concentration of 2-3 mol/L to reextract the loading organic phase obtained in the step (5), performing ammonia salting-out or thermal decomposition to obtain the end product. The method is simple and reliable; the industrialized production can be easily realized; the content of beryllium fluoride or beryllia is higher than 97%; the product quality is good; the recovery of beryllium is higher than 73%; the method is suitable for extracting beryllium from high-fluoride low-grade alexandrite-type beryllium mineral.
Owner:NORTHWEST RES INST OF MINING & METALLURGY INST

Method for removing heavy and light impurities in maleic anhydride system

The invention discloses a method for removing light impurities such as water, acetic acid and propylene and heavy impurities which can be condensed into tar in the maleic anhydride production field. According to two conventional technologies, a gas stripping column is arranged on the bottom of an absorption column so as to fill air for gas stripping, two switching coolers are arranged in front of the absorption column so as to respectively remove light and heavy impurities, and heavy impurities are condensed in the switching coolers in a practical operation process, so that cleaning is frequent and difficult; and the light impurities are subjected to gas stripping in the absorption column, so that the energy consumption is high, and the impurities cannot be thoroughly removed. According to the method, the gas stripping column is separately arranged, a column bottom is design to be conical, the light impurities are removed on the upper column part through air stripping, and the heavy impurities are removed on the column bottom through standing, so that the impurity content is effectively lowered, the product quality is improved, and an equipment blockage problem is solved; and moreover, the method is simple to operate and suitable for newly constructing and technologically reconstructing a solvent absorption maleic anhydride device, so that the economic benefit of the maleic anhydride production is greatly improved.
Owner:BEIJING QINTANG ENG CO LTD
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