Abstract: Use is made of a high-speed agitator comprising vessel 2 rotated at a low speed and bladed agitating element 3 rotated at a high speed in direction reverse to that of the vessel 2, the bladed agitating element 3 having a rotary axis arranged parallel to, and located apart from, the rotary axis of the vessel 2. Petroleum residuum such as solvent deasphalting residuum is agitated together with a grinding auxiliary and water in the high-speed agitator so that the petroleum residuum is ground. Thereafter, a dispersant is added thereto to form a slurry and the viscosity thereof is adjusted to a given value. A stabilizer is further added thereto to obtain a stable slurry. The dispersant and the stabilizer may be placed in the high-speed agitator prior to the grinding of the petroleum residuum. Thus, there is provided a process in which a high-concentration petroleum residuum-water slurry with a desirable particle size distribution, being cheap and highly stable, can easily be obtained by a one-stage grinding.

Abstract: Disclosed is a method of producing water slurry of SDA asphaltene by dispersing residue resulting from solvent deasphalting of petroleum vacuum residue produced in refineries, which has low viscosity even at a high solid concentration and is stable for a long period of time, in industrial scale under stable operation. The method comprises a grinding step of grinding the SDA asphaltene with water in a grinding apparatus in the presence of a dispersing agent, followed by a stabilizing step of stirring the resulting slurry to stabilize it. In the grinding step a suitable amount of a thickener such as carboxymethyl cellulose is added. Grinding is preferably carried out at a temperature not higher than 80.degree. C. Jacketed ball mills are conveniently used. In the stabilizing step a stabilizer such as Attapulgus clay is added after stirring the slurry to decrease viscosity thereof and stirring is continued.

Abstract: Electrolytes are attached to fluorescent particle surfaces to prevent open spots in cathode-ray tube coatings dried at high temperatures. Electrolytes that are sulfates, nitrates, or chlorides of alkali or alkaline-earth metals are added to a liquid suspension of fluorescent particles which have passed through a cleaning step. Electrolytes are added to the suspension to make the conductivity of the clear top liquid greater than 30 .mu..OMEGA..sup.-1 cm.sup.-1. The fluorescent particle preparation process is finished with a final dehydration and drying step.

Abstract: In a cathode-ray tube phosphor, a layer consisting of a substantially uniform SiO.sub.2 film or an organic film consisting essentially of at least one type of a polymer selected from the group consisting of an acrylic resin, gelatin, alginic acid, chitosan, and a urea resin is formed as a first layer on the surface of a phosphor particle, and a layer containing at least one type of a metal selected from the group consisting of Zn, Al, and an alkali earth metal and at least one member selected from the group consisting of a colloidal silica, an alumina sol, and a titania sol each having a particle size of 50 nm or less is formed as a second layer on the first layer. This phosphor is excellent in oxidation resistance and dispersibility.

Abstract: A cathode-ray tube phosphor is manufactured by coating, on the surfaces of phosphor particles, a mixture of a metal alginate containing at least one type of a metal selected from the group consisting of Zn, Al, and an alkali earth metal and at least one type of a water-soluble binder selected from the group consisting of gum arabic, gelatin, polymethacrylamide, and polyvinyl alcohol.

Abstract: A method of reclaiming a phosphor from a recovered phosphor slurry containing carbon, a bichromate, and polyvinyl alcohol, comprises, (a) a decomposition treatment step of adding an alkali to the recovered phosphor slurry after the slurry is heated to prepare a phosphor suspension having an alkali concentration of 0.5N or less in the slurry, and adding an oxidizing agent in an amount of 1.0 to 20.0 wt % with respect to a dry solid component of the suspension, (b) a weak acid treatment step of separating a phosphor from the suspension, and adding a weak acid to a suspension obtained by adding water to the separated phosphor, thereby adjusting a pH to be 3.0 to 5.0, and (c) a surface treatment step of treating the surface of the phosphor separated from the suspension.

Abstract: In a phosphor for a cathode-ray tube, a composition containing SiO.sub.2 and at least one element selected from the group consisting of indium, zirconium, and antimony is adhered on the surfaces of phosphor particles.