Process for the preparation of hollow spherical glass particles comprising at least SiO.sub.2, Al.sub.2O.sub.3, and an alkali metal oxide, wherein the process comprises the preparation of precursor particles comprising at least SiO.sub.2, Al.sub.2O.sub.3, and an alkali metal oxide by mixing the starting materials, slurrying the starting materials with water followed by spry-drying and heat-treating the obtained precursor-particles at a temperature from 1000° C. to 1800° C., preferably from 1300° C. to 1600° C. by contacting the precursor particles with at least one naked flame.

A high-strength geopolymer hollow microsphere, a preparation method thereof and a phase change energy storage microsphere are provided, including: dissolving sodium hydroxide, sodium silicate and spheroidizing aid in water to form a solution A, and adding active powder to the solution A, stirring and uniformly mixing to form a slurry B, adding the slurry B to an oil phase, stirring and dispersing into balls, filtering to obtain geopolymer microspheres I, washing the geopolymer microspheres I, and then carrying out a high-temperature calcination to obtain the high-strength geopolymer hollow microspheres II; using the high-strength geopolymer hollow microsphere as a carrier, absorbing a phase change material into the carrier, and mixing a microsphere carrying the phase change material with an epoxy resin, adding a powder dispersant and stirring to disperse the microsphere, after the epoxy resin is solidified, screening the superfluous powder dispersant to obtain the phase energy storage microsphere.

A method of manufacture of a powder comprising, or consisting essentially of, microspheres, the method comprising: providing a feed powder; and applying at least one spheroidisation flame to the powder. The powder may be suitable for use in medical and/or non-medical applications.

Hollow microbeads of glass are produced during a number of operating phases in which an upwardly directed hot gas flow is produced in a firing chamber by firing a vertical furnace. The firing chamber is continuously charged with microparticles of a starting glass material and the microparticles are expanded in the hot gas flow into the hollow microbeads. Expanded hollow microbeads are discharged out of the firing chamber with the gas flow through a gas outlet at the upper end of the vertical furnace. Between successive operating phases there is respectively provided a charging break, during which the charging of the firing chamber with the microparticles is suspended. In these charging breaks, the microparticles remaining in the firing chamber are respectively removed from the firing chamber.

A process and a plant produce hollow microspheres made of glass. According to the process an aqueous suspension is prepared from starting materials containing glass powder and water glass, feedstock particles having a diameter between 5 μm and 300 μm, in particular between 5 μm and 100 μm, being produced from the suspension. The feedstock particles are mixed with a pulverulent release agent made of aluminum hydroxide in an intensive mixer. The mixture of feedstock particles and release agent is subsequently introduced into a firing chamber of a furnace. The feedstock particles expand in the firing chamber, at a firing temperature which exceeds the softening temperature of the glass powder, to form the hollow microspheres.

Apparatus and methods for forming and printing hollow bodies from amorphous materials to form three-dimensional objects are provided. Apparatus provide a hollow body forming and printing machine, and methods for determining a desired amount of impact deformation for the hollow spheres, including calculating specific characteristics of the hollow spheres and the amorphous material, deriving a target viscosity range, adjusting the apparatus to satisfy the target viscosity range, and using the apparatus to form a plurality of hollow spheres with controlled deformation.

Apparatus and methods for forming and printing hollow bodies from amorphous materials to form three-dimensional objects are provided. Apparatus provide a hollow body forming and printing machine, and methods for determining a desired amount of impact deformation for the hollow spheres, including calculating specific characteristics of the hollow spheres and the amorphous material, deriving a target viscosity range, adjusting the apparatus to satisfy the target viscosity range, and using the apparatus to form a plurality of hollow spheres with controlled deformation.

Apparatus and methods for forming and printing hollow bodies from amorphous materials to form three-dimensional objects are provided. Apparatus provide a hollow body forming and printing machine, and methods for determining a desired amount of impact deformation for the hollow spheres, including calculating specific characteristics of the hollow spheres and the amorphous material, deriving a target viscosity range, adjusting the apparatus to satisfy the target viscosity range, and using the apparatus to form a plurality of hollow spheres with controlled deformation.

Apparatus and methods for forming and printing hollow bodies from amorphous materials to form three-dimensional objects are provided. Apparatus provide a hollow body forming and printing machine, and methods for determining a desired amount of impact deformation for the hollow spheres, including calculating specific characteristics of the hollow spheres and the amorphous material, deriving a target viscosity range, adjusting the apparatus to satisfy the target viscosity range, and using the apparatus to form a plurality of hollow spheres with controlled deformation.

A high-strength geopolymer hollow microsphere, a preparation method thereof and a phase change energy storage microsphere are provided, including: dissolving sodium hydroxide, sodium silicate and spheroidizing aid in water to form a solution A, and adding active powder to the solution A, stirring and uniformly mixing to form a slurry B, adding the slurry B to an oil phase, stirring and dispersing into balls, filtering to obtain geopolymer microspheres I, washing the geopolymer microspheres I, and then carrying out a high-temperature calcination to obtain the high-strength geopolymer hollow microspheres II; using the high-strength geopolymer hollow microsphere as a carrier, absorbing a phase change material into the carrier, and mixing a microsphere carrying the phase change material with an epoxy resin, adding a powder dispersant and stirring to disperse the microsphere, after the epoxy resin is solidified, screening the superfluous powder dispersant to obtain the phase energy storage microsphere.