Spherical balls and their manufacture

• US 4,446,207 A
• Filed: 12/16/1981
• Issued: 05/01/1984
• Est. Priority Date: 03/31/1978
• Status: Expired due to Fees

• Current Assignee: Spafi-- Societe Anonyme de Participations Financieres et Industrielles M Beigbeder
• Original Assignee: Saint-Gobain Isover (Compagnie De Saint-Gobain)
• Inventors: Aymard, Pierre, Dewitte, Jean
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): BUFFALOW, EDITH
• Application Number:
  US06/331,390
• Time in Patent Office: 867 Days
• Field of Search: 264/15, 264/5, 65/21.1, 65/21.3, 501/33, 428/426, 428/402, 428/406
• US Class Current: 428/402
• CPC Class Codes: C03B 19/104 by rolling, e.g. using revolving cylinders, rotating discs, rolls
• CPC Class Codes: C03B 5/14 in revolving cylindrical furnaces C03B5/02 takes precedence
• CPC Class Codes: C03C 10/00 Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
• CPC Class Codes: C03C 10/0045 containing SiO2, Al2O3 and MgO as main constituents
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/2996 Glass particles or spheres

Abstract

A process of forming glass balls by treatment of particulate vitreous material and a second material comprising carbon material and a carbonated salt. The process is carried out at a temperature, for the particular particulate vitreous material, which corresponds to a viscosity of from about 10⁶ to about 10³.5 poises with mixing and agitation.

The apparatus includes a furnace having a tube (4) adapted to rotate about an horizontal or inclined axis, delivery means (10, 12, 14) to the tube for the materials to be treated, and heating means (8, 20) for heating the tube and the bed of material from both an external and internal location.

Claims

1. A product formed of a particulate ceramizable glass material having a granular dimension of about 1 to about 3.5 mm and a substantially rounded, spherical shape by a thermal treatment within a temperature range of from about 950°

to about 1200°

C., said material having a crystallization rate of at least 30%, essentially in the form of wollastonite α and

β

, and a resistance to crushing of at least 4,000 bars.

2. The product of claim 1 wherein said material is formed to a ball having a diameter of from about 0.8 to about 3 mm.

3. The product of claim 1 wherein said material has an instantaneous viscosity from about 10⁶ to about 10³.5 poises within said temperature range.

4. The product of claim 1, 2 or 3 wherein said material has a composition (by weight percent) of