A method is provided for leaching the metals while granulating molten matte, comprising the steps of feeding a molten matte as a falling stream into a granulation chamber, spraying a liquid jet on the stream of molten matte to atomize the matte, and cooling the matte particles thus formed. The liquid jet comprises an acid solution containing water and sulfuric acid so that the acid solution starts leaching metals from the molten matte when the liquid jet contacts the molten matte. Part of product solution from granulation can be circulated to liquid jets to increase the metal content in the solution and to reduce its acid con-tent.

A method is provided for leaching the metals while granulating molten matte, comprising the steps of feeding a molten matte as a falling stream into a granulation chamber, spraying a liquid jet on the stream of molten matte to atomize the matte, and cooling the matte particles thus formed. The liquid jet comprises an acid solution containing water and sulfuric acid so that the acid solution starts leaching metals from the molten matte when the liquid jet contacts the molten matte. Part of product solution from granulation can be circulated to liquid jets to increase the metal content in the solution and to reduce its acid con-tent.

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.

The invention relates to a blank for producing a dental molded part such as an inlay, onlay, crown or bridge, and to a method for producing the blank. To be able to machine a dental molded part, in particular one having thin wall thicknesses, from the blank without difficulty, the blank is designed to consist of a glass ceramic having a density of between 30 and 60% of theoretical density, and of glass-ceramic powder particles with a particle size distribution d.sub.90≦80 μm, lithium silicate crystals being present in an amount of 10 to 90% by volume.

Microspheres comprising a plurality of hollow microspheres, each of the plurality of hollow microspheres comprising a plurality of glass walls, and a plurality of hollow spaces, wherein the plurality of glass walls enclosing at least one of the plurality of hollow spaces, wherein the plurality of glass walls comprising a second glass, wherein the second glass comprising a processed first glass melt, wherein the processed first glass melt comprising a melt of a batch and a plurality of redox active group components capable of providing at least one of a plurality of redox reactions and a plurality of events in the second glass.

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.

Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods makes use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods makes use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

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.

Methods and apparatus are disclosed for producing seeds that are transformed into hollow spheres. A seed includes a core and a coating. Upon heating, the coating becomes viscous and expands responsive to an internal gas pressure created by the core. Example applications for the seeds and/or cores are disclosed, including bricks and other construction materials having the hollow spheres incorporated therein.