525results about How to "High chemical purity" patented technology

The invention relates to an Al2O3-SiC-C castable material for a slag line of a main trough of a large blast furnace and a preparation method thereof. The castable material comprises an aggregate, a matrix, a bonding agent, an antioxidant and an admixture; wherein, the aggregate comprises corundum grains and carborundum grains; the matrix comprises ball pitch, flake graphite, corundum fine powder, a-Al2O3 ultrafine powder, silicon powder and carborundum ultrafine powder; the bonding agent is aluminate cement; the antioxidant is a compound of aluminium powder and silicon powder; the admixture comprises a water reducing agent and a detonation suppressor. The castable material is prepared by the steps of mixing various raw materials evenly, adding water, stirring, casting molding, maintaining and drying. The castable material has strong anti-slag corrosion and anti-scour capabilities, good high temperature resistance, abrasion resistance and thermal shock resistance, slight reheating change and long service life.

The invention relates to the technical field of lubricating grease, in particular to organic silicon lubricating grease and a preparation method thereof. The organic silicon lubricating grease comprises the following components in percentage by mass: 10 to 80 percent of base oil, 1 to 30 percent of modifier and 5 to 25 percent of thickening agent. The organic silicon lubricating grease has the advantages of wide application range, excellent dielectric property, insulating property, sealing property, thermal stability, shockproof property and lubricating property, and obvious improvement on lubricating property and thermal stability particularly.

The present invention relates to a preparation method of high-purity aluminium oxide powder body. It is characterized by that it adopts aluminium sheet whose purity is 99.9999% and organic alkal; and makes them be mutually reacted in hot water bath to obtain the precipitate of aluminium hydroxide, then the precipitate is calcined at 1100-1200deg.C and ground so as to obtain high-purity ultrafine aluminium oxide powder body. The described organic alkal; includes any one of choline, hexamethohydrotetramine and dopamine.

The invention relates to a preparation method of ternary system material, in particular to a preparation method of lithium cobalt nickel manganese oxide ternary system material for lithium ion batteries. The invention applies ensured ternary system material salt as raw material. After needed matching weight, by means of eve dissolving and mixing, a composite metal oxide prepared by a spray-roasting method is used as a fore body. The fore body is mixed with a lithium-source compound according to the substance amount of 1:1-1.5, and then roasting is carried out at the temperature of 700 to 1000 degrees centigrade to obtain the ternary system material. The tail gases, such as vapor, acidic gas, generated in the spray-roasting process are absorbed by a washing tower to obtain acid. The invention has the advantages of advanced technique, stable production, low cost, no waste water discharge, environmental protection, high product purity, even granularity, high crystallinity, etc.

The present invention relates to a process for efficiently producing an optically active 2-bromocarboylic acid and an optically active 2-sulfonyloxycarboxylic acid, which are important in the production of medicinal compounds and so forth. An optically active 2-sulfonyloxycarboxylic acid ester is subjected to deprotection under acid conditions to obtain an optically active 2-sulfonyloxycarboxylic acid. A metal bromide is caused to act on the acid to brominate it with configuration inversion at position 2 to thereby produce an optically active 2-bromocarboxylic acid. The resultant optically active 2-bromocarboxylic acid is isolated/purified by subjecting it to a step in which the acid is crystallized and separated as a salt with a base. Thus, an optically active 2-bromocarboxylic acid having a high chemical purity and high optical purity can be produced.

A preparation method of a high-stability high-purity extra-coarse tungsten carbide powder contains the following steps of: (1) grinding a high-purity extra-coarse tungsten carbide powdered raw material with its chemical purity being greater than or equal to 99.98 wt%, and carrying out size grading to obtain the required average granularity and a high-purity extra-coarse tungsten powder according to the particle size distribution; (2) carrying out carbon addition by the use of carbon black according to the total carbon content of the obtained tungsten carbide powder being 6.13+/-0.05%, followed by ball milling and mixing to obtain a ball-milling mixture; (3) filling the obtained ball-milling mixture into a graphite boat and a carbide furnace, and carrying out high-temperature carbonization at 1600-2500 DEGC for the carbonization time of 1-10 hours; and (4) carrying out coarse crushing on the obtained carbonized material, followed by grinding and crushing, and carrying out size grading to obtain the high-purity extra-coarse tungsten carbide powder. The method provided by the invention can be adopted to produce the high-purity extra-coarse tungsten carbide powder with good crush resistance, morphology and structure and excellent thermal stability. The high-purity extra-coarse tungsten carbide powder is used to prepare an extra-coarse crystal cemented carbide product with high performance.

A two-layer ceramic composite material, wherein the first predominantly load-bearing layer is an oxidic, carbon-free fiber-reinforced ceramic layer which is made by a colloidal process. The second predominantly thermally insulating layer is an oxide-ceramic foam. The colloidal process produces carbon-free oxide ceramics which, because of their high purity, have low dielectric losses in the entire usage temperature range. In addition, the colloidal process provides a simple and cost-effective production method.

The invention relates to a device and a method for dynamically preparing heterocavity bacterium cellulose materials. The device comprises a thermometer hole, an acid liquor and alkali liquor adding hole, a handle, a venting hole, a pH meter hole, a nutrition supplement hole, a rotating shaft, a fermentation tank, a motor, a water bath device and a mould. The preparation method comprises the following steps of: inoculating bacterium cellulose strains into a fluid nutrient medium to be propagated and then transferring to a fermentation device provided with specific shape moulds for later dynamic disturbance cultivation, and then obtaining the heterocavity cellulose materials after the cultivation step. The size and the shape of the heterocavity BC (Bacterium Cellulose) materials prepared by utilizing the invention are controllable, and the moulds of the fermentation device can be detached to be reused. The preparation method has the advantages of simple and convenient implementation, low cost and high production efficiency, and is suitable for industrialization production. The heterocavity BC materials can be widely applied to cavity organ succedaneums of artificial vessels, nerve fiber conduits and the like, and can be used as food packing materials, such as meat sausage wrappers, jelly wrappers and the like.

The invention belongs to the powder metallurgy field and particularly relates to a preparation method of free-cutting water-atomized steel powder. The method comprises the following steps of smelting, water atomization and reduction. The method provided by the invention is characterized in that the S content in the steel powder is controlled by adding high sulfur iron alloy. The method comprises the following operation steps: 1) smelting; 2) performing the water atomization technology; and 3) reducing. The free-cutting water-atomized steel powder prepared by the method comprises the following chemical components in percentage by weight: 0.10-0.20% of C, 0.20-0.35% of Si, 0.10-0.30% of Mn, 0-0.01% of P, 0.30-0.45% of S, 1.1-1.5ppm of [o] and balance of Fe and inevitable impurities. The water-atomized steel powder has the following beneficial effects: the used steel scrap raw material has low cost, the cutting property can be effectively improved, the service life of the cutting tool can be increased, and the steel powder is suitable for large-scale powder metallurgical products.

The invention discloses escherichia coli for efficiently producing L-alanine by fermentation, and belongs to the technical field of microbial metabolic engineering. Coding genes for a synthesis route for byproducts acetic acid, formic acid, alcohol, succinic acid and lactic acid on a chromosome of escherichia coli CGMCC No.10628 provided by the invention are deleted, and the chromosome dadX gene is replaced as an alanine dehydrogenase gene, wherein the coding genes comprise ackA-pta, pflB, adhE, frdA and idhA. The recombinant bacterium is fermented for 26 hours to produce 106g/L or more than 106g/L L-alanine with high optical purity and high chemical purity at 28-45 DEG C; and in the whole fermentation process, the production strength reaches 4.27g/L.h or more.

The invention provides a 4 - dihydroxy boryl - L-phenylalanine preparation method which is as follows: reacting amino terminal-protected (S) - 4 -halogeno phenylalanine shown as the formula (I) with a boriding agent and an organic lithium compound to obtain a reaction mixture containing amino terminal-protected (S) - 4 - dihydroxy boryl phenylalanine shown as the formula (II) with R being a protective group; separating the reaction mixture to obtain the amino terminal-protected (S) - 4 - dihydroxy boryl phenylalanine; and de-protecting the amino terminal-protected (S) - 4 - dihydroxy boryl phenylalanine to obtain 4 - dihydroxy boryl - L-phenylalanine.

The present invention relates to preparation process of magnesium compound, and is especially preparation process of magnesia for silicon steel. The present invention produces silicon steel level magnesia through a bittern-sodium carbonate process, which includes reaction of refined magnesium chloride solution and refined sodium carbonate solution at 65-85 deg.c for 5-15 min to produce basic magnesium carbonate, curing, filtering and calcining at 1100+/-50 deg.c for 2.0+/-0.5 hr. Thus produced silicon steel level magnesia has high purity, small average grain size, good coating performance, high adhesivity and other features, and the preparation process is simple and low in cost.

The invention relates to a radiation crosslinked polyethylene tube, which has a stereoscopic netted cross-linking molecular structure, and the process comprises: extruding the mixture in a finite proportion of polyvinyl resin, anti-oxidizing agents and stearic acid salt lubricating agents as raw materials in the temperature of less than 235 Deg. C to get the tubes by a tube extruder, then radiating by electron-beams to get the product. The components of the said raw materials is with a proportion of polyvinyl resin of 98.5-99.0 wt%, anti-oxidizing agents of 0.1-0.6 wt% and stearic acid salt lubricating agents of 0.5-1.0 wt%, and the degree of molecular crosslinking in the inner of the said tubes is more than 60 %.

The invention discloses self-crosslinking acrylate emulsion and a preparation method thereof. The self-crosslinking acrylate emulsion is prepared from (methyl) acrylate monomer, a functional monomer, a crosslinking monomer, a crosslinking agent, an emulsifying agent A, an emulsifying agent B, a buffering agent, an initiator, an oxidizer, a reducer and deionized water, wherein the reducer is an FF6M macromolecule polymerization novel reducer produced by a Bruegmann company in Germany, the emulsifying agent A is an emulsifying agent AEROSOL A-501 produced by a Cytel company in America, and the emulsifying agent B is an emulsifying agent AEROSOL MA-80 produced by the Cytel company in America; the preparation method of the self-crosslinking acrylate emulsion comprises pre-emulsification, emulsification and post treatment. A superfine glass fiber separating plate made by adopting the self-crosslinking acrylate emulsion is low in potassium hypermanganate reduzate content, high in liquid absorption speed, high in amount of absorbed liquid and excellent in performance.

A method of selectively preparing a chiral 2S-amino alcohol useful in preparation of an amide sulfonated or acylated with alkyl, substituted aryl or substituted heteroaryl is described. The method involves reacting a di-tert-butyl diazene-1,2-dicarboxylate with a (4S)-4-benzyl-3-[(S)-trifluoromethyl-alkyl substituted alkanoyl]-1,3-oxazolidin-2-one to afford a di-tert-butyl 1-(1S,2S)-([(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate. This dicarboxylate is then reduced to yield di-tert-butyl 1-(1S,2S)-[trifluoromethyl-alkyl substituted alkyl]hydrazine-1-(hydroxymethyl)-1,2-dicarboxylate. The resulting product is deblocked with an acid to yield the acid addition salt of (2S,3S)-trifluoro-hydrazino-methyl alkan-1-ol. The acid addition salt of (2S,3S)-trifluor-2-hydrazino-methyl alkan-1-ol is hydrogenated in the presence of a suitable metal catalyst to yield the amino alcohol (2S,3S)-2-amino-trifluoro-methyl alkan-1-ol HCl.

A Strain producing dynamic controlling recombinant strain and a method for preparing D-lactic acid with the recombinant strain belong to the technical field of genetically engineered agricultural microorganisms. The recombinant strain is named (Escherichia coli)B0013-070B, and is preserved in the China center for type culture collection, and the preservation number is CCTCCNO:M2012071. A lactate dehydrogenase gene promoter ldhAp in the genome of the strain is replaced with a culture environment/nutritional factors control-type promoter. Through the utilization of the recombinant strain, fermentation is conducted for 28 to 40 hours in stages at 25 to 50 DEG C, and the level of producing D-lactic acid reaches 12.5%; the optical purity lives up to 99.9%; and the chemical purity reaches to 98.4%. The dynamic controlling to the D-lactic acid dehydrogenase encoding gene expression on D-lactic acid high-producing strain B0013-070 chromosomes is conducted, so that the gene expression is controlled only through changing the fermentation temperature during the D-lactic acid production process to achieve the purpose of efficiently synthesizing D-lactic acid through taking glucose as a raw material. After simple modification, the invention can be used for producing important microbial metabolites in other industries.

The present invention is broadly directed to novel compounds useful for the synthesis of biologically active compounds, including taxane derivatives, and convergent processes for the preparation of these taxane derivatives and their intermediates.

The invention relates to a multipurpose polyester film and a preparation method thereof. The preparation method adopts a biaxial orientation technique and comprises the following steps: 1. preparation of functional assistants; 2. precrystallization and drying; 3. melt extrusion: the precrystallized and dried PET (polyethylene terephthalate) slices and the functional assistants are heated and molten by an extruder, and the melt is uniformly delivered to a die head for slab casting under the push of extrusion pressure; 4. slab casting: the uniform and stable melt from the extrusion system runs on rotating quenching rollers through the die head to form an amorphous slab; 5. longitudinal stretching and lateral stretching: the cast slab is subjected to longitudinal stretching after entering a longitudinal stretching machine, and subjected to lateral stretching after entering a lateral stretching machine; and 7. pulling, slicing, corona treatment, rolling and inspection. The method has wide application range, such as environment-friendly films, twist wrap films, high-brightness films, insulation films, capacitive films, car protecting films, bronzing films, aluminizing films and composite packaging films.