Abstract: A method for removing a halogen series gas, which comprises bringing a halogen series gas comprising a halogen element or a halogen compound into contact with a granulated product, wherein the granulated product is obtained by granulating a powder of a hydrogencarbonate having a mean particle diameter of primary particles of from 10 to 500 &mgr;m, and has a mean particle diameter of from 0.

Abstract: A purification method for an alkali metal chloride, which comprises separating, from a mixture comprising one type of alkali metal chloride and other water-soluble inorganic salt, said other water-soluble inorganic salt, to purify said alkali metal chloride, wherein water or an aqueous solution of said alkali metal chloride is added to said mixture in such an amount that is sufficient to dissolve at least one type of said other water-soluble inorganic salt substantially in its entire amount and that is not sufficient to dissolve said alkali metal chloride substantially in its entire amount, thereby to dissolve said other water-soluble inorganic salt substantially in its entire amount, and the obtained slurry is subjected to solid-liquid separation to recover the solid component.

Abstract: An acid component-removing agent which comprises sodium hydrogencarbonate having a volume-based mean particle diameter of from 1 to 9 &mgr;m as measured by a laser diffraction and scattering method.

Abstract: A process for producing an alumina sol, which comprises stirring a dispersion of an alumina hydrate having a solid content of from 1 to 40 wt % at a pH of from 7 to 12 with an effective consumptive power of at least 0.5 kW/m3 for aggregation treatment, and then adding an acid thereto for peptization treatment.

Abstract: A sodium-based dechlorinating agent g is added to a flue gas G6; hydrogen chloride contained in this flue gas is removed as residue of dechlorination; the thus removed residue of dechlorination is dissolved by adding water i; water-insoluble constituents k are separated from the resulting aqueous solution j; and after adjusting pH of the aqueous solution l remaining after separation of the water-insoluble constituents k, mercury, dioxin and the like are removed and discharged. The sodium-based dechlorinating agent g is mixed with a hydrophilic anti-caking agent, with an angle of repose of 40° or more, a dispersibility of less than 50, and a floodability index value of less than 90. A mean particle diameter of sodium hydrogencarbonate is set within a range of from 2 &mgr;m to 30 &mgr;m. The hydrophilic anti-caking agent comprises silica, and is contained in an amount of 0.1 mass % or more in the sodium-based dechlorinating agent.

Abstract: A method for treating a gas containing a SO3 component, which comprises adding a sodium carbonate powder having a mean particle diameter of at most 20 &mgr;m to the gas to remove the SO3 component from the gas.

Abstract: Hollow aluminosilicate glass microspheres which are hollow glass microspheres having an average particle size of from 1 to 20 &mgr;m based on volume, an average particle density of from 0.20 to 1.50 g/cm3, a sphericity within a range of 1≦(long axial length/short axial length)<1.2 and a composition comprising from 30 to 85 mass % of SiO2, from 6 to 45 mass % of Al2O3, from 0 to 30 mass % of an alkali metal oxide, from 0 to 30 mass % of an alkaline earth metal oxide and from 0 to 1 mass % of B2O3, and which have a strength at 10 volume % collapse of at least 10% of the theoretical strength given by the formula 16.7×E×(t/2a)2.5, where E is the Young's modulus (unit: GPa) of the glass constituting the hollow glass microspheres, t is the thickness (unit: mm) of the shell of the hollow glass microspheres, and a is the hollow radius (unit: mm) of the hollow glass microspheres.

Abstract: A method for removing an acidic deposit containing a sulfur compound, which comprises contacting the acidic deposit with an aqueous solution of an alkali metal carbonate and/or an alkali metal hydrogencarbonate to remove it.

Abstract: It is an object of the present invention to obtain solid spherical silica particles having no depression or crack on the surface. The present invention provides a process for producing spherical silica particles, which comprises dispersing silica gel particles having an average particle size of from 0.05 to 3.0 &mgr;m in a mixed solution of an alkali silicate and an acid, spraying the dispersion to obtain droplets, and heating the droplets in a gas and gelating the mixed solution portion of an alkali silicate and an acid in the droplets.

Abstract: A process for producing an alumina sol, which comprises stirring a dispersion of an alumina hydrate having a solid content of from 1 to 40 wt % at a pH of from 7 to 12 with an effective consumptive power of at least 0.5 kW/m.sup.3 for aggregation treatment, and then adding an acid thereto for peptization treatment.

Abstract: A blasting medium composed of a granulated product which comprises a water-soluble inorganic salt as the main component and which has a weight average grain size of from 1 to 10 mm.

Abstract: A process for producing inorganic microspheres (solid spheres or hollow spheres), which comprises pulverizing a material by wet pulverization to an average particle size of at most 5 .mu.m to obtain a slurry of a pulverized powder material, spraying the slurry to form liquid droplets, and heating the liquid droplets to fuse or sinter the powder material to obtain inorganic microspheres.