Showing papers on "Jet mill published in 1989"

Process and apparatus for coating fine powders

Abstract: There is disclosed a process for coating fine powder of a metal, a ceramic, a plastic or an organic pigment with a metal or a ceramic comprising: (a) dispersing particles of said fine powder into primary particles by fluid jet mill treatment in an inert atmosphere; (b) heating the dispersed fine powder in an inert atmosphere under reduced pressure; (c) placing the heated powder in an evacuable rotary barrel sputtering chamber, forming a fluidized bed by rotating the barrel at a low speed and coating said fluidized powder by sputtering as the barrel is being rotated. By this process, fine powders of metals, ceramics and plastics having a particle diameter of 0.1-10µm can be uniformly coated by a metal or a ceramic. There is also provided an apparatus therefor.

Process for micronizing solid matter in jet mills

Abstract: A process for micronizing solid matters in a jet mill, wherein the solid matters are brought into the jet mill across an injector and wherein the micronization takes place, if necessary, in the presence of milling aids and/or dispersing agents, wherein the solid matters are forcibly supplied to the injector and an apparatus for carrying out the process, the apparatus comprising a dosing means, a forcible entry means, and injector and a jet mill.

Production of fine fused spherical silica

Abstract: PURPOSE: To obtain fine fused spherical silica in good yield by melting a silica raw material with a frame formed by combustion of a combustible gas and oxygen and introducing a cooling gas into a flame-forming zone. CONSTITUTION: A silica raw material is melted with a flame formed by combustion of a combustible gas and oxygen to produce fused spherical silica. In the process, a cooling gas is introduced into a frame-forming zone. The silica raw material used is preferably natural or synthetic silica of a as high a purity as possible. Purified quartzite, quartz sand, rock crystal, etc., are cited as the natural silica and silica which is a hydrolyzate of an organosilicate, such as ethyl silicate, prepared by hydrolyzing a silicon halide or neutralizing an aqueous solution of an alkali silica, etc., is cited as the synthetic silica. The above- mentioned silica raw materials are finely pulverized in a desired pulverizer, such as ball mill or jet mill. In most cases, the average particle diameter is ≤10μ, preferably within the range of 2-8μ. COPYRIGHT: (C)1990,JPO&Japio

Dispersion, comminution or deagglomeration and classification of solids

Abstract: Solids are dispersed, comminuted or deagglomerated and classified in a single piece of equipment, a classifier jet mill representing a combination of a jet mill and a spiral flow classifier.

Sinterable SI3 N4 powders containing sintering additives and a process for their preparation

Abstract: Sinterable Si3 N4 powder containing Si3 N4 particles and sintering additives wherein Si3 N4 particles have an average particle size of less than 1 μm, contain no particle having a diameter greater than 100 μm, have a total content of metallic impurities less than 1000 ppm and an iron content of less than 200 ppm, and wherein the sintering additives are uniformly distributed throughout the powder is prepared by co-grinding pulverulent sintering additive and Si3 N4 containing less than 1000 ppm metallic impurities in a spiral jet mill.

Manufacture of electrostatic charge image developing toner

Abstract: PURPOSE:To bring out the pulverizing ability and the energy efficiency of a pulverizing device to their utmost and to manufacture a toner capable of forming an image high in density and small in fog with a correct consumption of the toner by finely pulverizing the crude toner with high impact by using a jet mill, and further giving comparatively low impact to it as compared with the first impact for a short time. CONSTITUTION:The crude material to be pulverized 1 is fed to a first classifying means 2, the classified particles larger than a prescribed particle size range 3 is fed to a high impact pulverizing means 4, the pulverized particles are again fed to the means 2, the finer particles are fed to a low impact treating means 5, the treated particles are fed to a second classifying means 6, and classified into particles finer than a prescribed size range 7 and particles in the prescribed size range 8. The jet mill is used for the means 4, and the low impact treatment is executed, for example, by giving impact to the particles between a rotor and a liner, thus permitting deterioration of the image density due to the high impact pulverization to be covered by the low impact treatment, and an image high in density to be obtained, and both of the treatment capacity of the device and the energy efficiency to be enhanced.

Method for the activation of a carrier for a polymerization catalyst, and a catalyst component obtained using the method

Abstract: The invention relates to the improving of the particle structure of carrier compounds for polymerization cata-lysts, and thereby to the improving of the activity of the entire catalyst, by jet grinding one or more carrier com-pounds (4), or a mixture of the same, in a grinding chamber in which one or more gas jets (2) transport particles (4) of the material to be ground finely, at such a force against each other and/or against one or more anvils (5) of the jet mill that the particles are pulverized into a fine-ly-divided chemically active carrier.

Sinterable Si3N4 powder and a process for its preparation

Abstract: Sinterable Si3N4 powder having an average particle size of less than 1 mu m, wherein no individual particle has a diameter greater than 100 mu m, the total content of metallic impurities of the powder is less than 1000 ppm and the iron content is less than 200 ppm is produced by grinding agglomerated Si3N4 in a spiral jet mill.

Production of ceramic superconducting material

Abstract: PURPOSE:To densify a superconducting material and to improve a critical current density in producing the superconducting material by subjecting a raw material of oxide-based superconducting substance blended in a superconducting substance composition to kneading-calcining-grinding-molding and sintering, by specifying the grinding and sintering methods. CONSTITUTION:Each oxide powder blended in a superconducting composition is repeatedly calcined and ground until a single phase of superconducting mate rial is obtained and the powder is finally ground in an anhydrous organic disper sion medium by a ball mill or jet mill to give fine powder having =3mu, uniform denseness is not sufficient and high critical current density JC can not be attained. The sintering condition should be made to select a lower temperature side than the above-mentioned range if the particle size of the fine powder before the sintering is small and uniform. But if the sintering temperature is <900 deg.C, sintering is insufficient and JC is extremely lowered.

Crystallite size and residual microstrain analysis on shock-modified and jet-milled LaB sub 6 powders

Abstract: Lanthanum boride powder compacts have been subjected to controlled, quantitative high pressure shock loading at peak pressures from 5-22 GPa Separated samples of the same powdered material have also been jet-milled under various conditions The broadened x-ray diffraction profiles of these materials processed using the two techniques have been analyzed to determine the coherent crystallite size and the residual lattice strain The particle size distributions of the jet-milled powders were also analyzed by sedigraph measurements Equivalency of shock loading and jet-milling has been shown under certain processing conditions

Purification of 2-chloro-6-methylaminopyridine

Abstract: PURPOSE:To readily purify the title compound in an approximately quantitative recovery ratio, by grinding the title compound obtained by reaction between 2,6-dichloropyridine and methylamine in the presence of water into <= specific particle diameter or grinding to the specific particle diameter and washing with water. CONSTITUTION:2-Chloro-6-methylaminopyridine obtained by reaction between 2,6-dichloropyridine and methylamine is ground in the presence of water into <=500mum average particle diameter, preferably 5-500mum or ground into the particle diameter and washed with water to give 2-chloro-6-methylaminopyridine industrially and advantageously. Dry grinding method using jet mill or wet grinding method using sand mill may be used as the grinding method.

Grinding of gelatin, resin film, resin coat and coating material

Abstract: PURPOSE:To make it possible to use gelatin as a part of a resin film, a resin coat or a coating component by uniformly and finely grinding gelatin without detriment to its characteristic properties, by grinding a powdery or particulate gelatin with a jet mill and classifying the product of grinding to form a powder of a specified fine particle diameter CONSTITUTION:Powdery or particulate gelatin is preferably preground to form a powder or particles of a mean particle diameter of 100mum, and then ground with a jet mill operated with, for example, low-temperature air of-15 degC, and the obtained product of grinding is classified to obtain a gelatin powder or a particle diameter finer than 6mum

A method for the activation of a carrier for a polymerization catalyst

Abstract: The invention relates to the improving of the particle structure of carrier compounds for polymerization cata­lysts, and thereby to the improving of the activity of the entire catalyst, by jet grinding one or more carrier com­pounds (4), or a mixture of the same, in a grinding chamber in which one or more gas jets (2) transport particles (4) of the material to be ground finely, at such a force against each other and/or against one or more anvils (5) of the jet mill that the particles are pulverized into a fine­ly-divided chemically active carrier.