Showing papers on "Jet mill published in 1981"

Method for the production of micropowders from cellulose ethers or cellulose

Abstract: A method for the production of micropowders from cellulose ethers or cellulose comprising (a) subjecting a cellulose ether or a cellulose having a fine-fiber, cottony or woolly structure to a consolidation or embrittlement sufficient whereby in one mill pass through a jet mill under standard conditions 98% by weight of the consolidated or embrittled material charged is recovered as a powder of less than 100μ, and (b) subjecting the consolidated or embrittled material to a grinding step producing a size reduction sufficient that a grain size distribution with at least 90% by weight of less than 125μ is attained.

Production of dispersion of organic azonitrile fine particle

Abstract: PURPOSE:To easily produce titled dispersion useful as an initiator for suspension polymerization, by carrying out the production in the presence of a dispersant and in an atmosphere of an inert gas. CONSTITUTION:In producing an aqueous dispersion of an organic azo type polymerization-initiating compound such as 2,2'-azobisiso-butyronitrile or 2,2'-azobis(2, 4-dimethylvaleronitrile), in which dispersion, a major portion of said azo type compound is present in the form of fine particles having a particle diameter of about 10mu or below, said compound which is solid at ordinary temperature or below is pulverized into particles, particle diameter <=10mu, by a jet mill or the like. Then, the aqueous dispersion is prepared by dispersing the resulting fine particles into water in the presence of a dispersant such as polyethyleneimine, polyvinylpyrrolidone, methyl cellulose, carboxylmethyl cellulose, gum arabic or carrageenan in an atmosphere of an inert gas by the use of a homogenizer or a kneader.

A Consideration of the Differential Grinding of Quartz and Feldspar in Weathered Granite

Abstract: An experimental study has been made to obtain the compressive strength and Martens scratching hardness of quartz, alkali feldspar and plagioclase particles. These minerals were sorted from weathered granite according to the weathering degree. The compressive strength and hardness of weathered plagioclase particles showed a prominent decrease due to argillization against the unweathered ones as compared with the other two minerals. The different behaviour of the compressive strength and hardness of each mineral suggests that the abrasive grinding mechanism may be more effective than compressive one for differential grinding.Laboratory scale mill tests were carried out with the samples of weathered granite by using pot mill, jet mill and hammer mill. The results of the differential grinding show that pot mill was more effective than jet and hammer mills in the amount of grinding for plagioclase particles.

Dry manufacture of uranium dioxide powder with superior sinterability

Abstract: PURPOSE:To economically manufacture the titled uranium dioxide powder by a dry process by reducing uranium trioxide formed by fluidized thermal decomposition and pulverizing the resulting uranium dioxide with a jet mill. CONSTITUTION:Uranyl nitrate is thermally decomposed in a fluidized bed, and the resulting uranium trioxide is reduced in a hydrogen atmosphere at about 500-900 deg.C in a fluidized bed type reducing furnace to form uranium dioxide. This uranium dioxide is pulverized with a jet mill pulverizer using air as carrier gas to obtain uranium dioxide powder having superior sinterability and suitable for manufacturing nuclear fuel pellets. The ratio of oxygen/uranium is preferably adjusted to about 2.05-2.12 in the above-mentioned jet mill pulverization.

Fine milling of fused mullite and mullite-corundum

Abstract: Milling time during the fine grinding of fused mullite and mullite-corundum powders in a vibromill instead of a ballmill can be reduced by a factor of five The addition of sulfite lye or ethyl silicate in amounts of 01% reduces by a factor of 12–18 the vibromilling time, but iron pickup is increased Grinding in a jet mill causes the specific surface to be much less than milling in a vibromill; the capacity for sintering such powders is impaired