A method for forming a glass frit for additive manufacturing includes providing a mixture having at least one silicon (Si) compound, at least one calcium (Ca) compound, and at least one zirconium (Zr) compound; melting the mixture at a temperature of at least 1400° C.; cooling the mixture to room temperature to obtain the glass frit including at least 50 wt. % SiO.sub.2, at least 30 wt. % CaO, and at least 10 wt. % ZrO.sub.2.

Glass manufacturing methods disclosed herein include delivering a molten glass to a melting vessel, and melting the batch materials to produce a molten glass comprising less than about 20 ppm CrO.sub.3. Glass articles produced by these methods are also disclosed herein.

Glass manufacturing methods disclosed herein include delivering a molten glass to a melting vessel, and melting the batch materials to produce a molten glass comprising less than about 20 ppm CrO.sub.3. Glass articles produced by these methods are also disclosed herein.

A method for producing hollow glass microspheres includes preparing an aqueous suspension of starting materials including finely ground glass and waterglass. Combustible particles are produced from the suspension and are mixed with an AlO(OH)-containing pulverulent release agent. The mixture of combustible particles and release agent is introduced into a combustion chamber of a furnace where it is expanded at a combustion temperature which exceeds the softening temperature of the finely ground glass, to form the hollow microspheres. Hollow glass microspheres produced according to the method are also provided.

A method for producing hollow glass microspheres includes preparing an aqueous suspension of starting materials including finely ground glass and waterglass. Combustible particles are produced from the suspension and are mixed with an AlO(OH)-containing pulverulent release agent. The mixture of combustible particles and release agent is introduced into a combustion chamber of a furnace where it is expanded at a combustion temperature which exceeds the softening temperature of the finely ground glass, to form the hollow microspheres. Hollow glass microspheres produced according to the method are also provided.

A method for producing a solid electrolyte, comprising: grinding raw materials comprising lithium sulfide and phosphorus sulfide in a hydrocarbon solvent, optionally comprising stirring a slurry comprising the raw materials and the hydrocarbon solvent in a reaction vessel, and optionally, circulating the slurry through a connecting pipe, wherein the method is carried out in an apparatus comprising the grinder, the reaction vessel and the connecting pipe that connects the grinder and the reaction vessel.

A method for producing a solid electrolyte, comprising: grinding raw materials comprising lithium sulfide and phosphorus sulfide in a hydrocarbon solvent, optionally comprising stirring a slurry comprising the raw materials and the hydrocarbon solvent in a reaction vessel, and optionally, circulating the slurry through a connecting pipe, wherein the method is carried out in an apparatus comprising the grinder, the reaction vessel and the connecting pipe that connects the grinder and the reaction vessel.

A method of producing glass using submerged combustion melting is disclosed. The method includes introducing a vitrifiable feed material into a glass melt contained within a submerged combustion melter. The glass melt contained in the melter has a redox ratio defined as a ratio of Fe.sup.2+ to total iron in the glass melt. The method further includes combusting a combustible gas mixture supplied to each of the submerged burners to produce combustion products, and discharging the combustion products directly into the glass melt. Still further, the method includes adjusting the redox ratio of the glass melt by controlling one or more operating conditions of the submerged combustion melter selected from (1) an oxygen-to-fuel ratio of the combustible gas mixture supplied to each of the submerged burners, (2) a residence time of the glass melt, and (3) a gas flux through the glass melt.

A method of producing glass using submerged combustion melting is disclosed. The method includes introducing a vitrifiable feed material into a glass melt contained within a submerged combustion melter. The glass melt contained in the melter has a redox ratio defined as a ratio of Fe.sup.2+ to total iron in the glass melt. The method further includes combusting a combustible gas mixture supplied to each of the submerged burners to produce combustion products, and discharging the combustion products directly into the glass melt. Still further, the method includes adjusting the redox ratio of the glass melt by controlling one or more operating conditions of the submerged combustion melter selected from (1) an oxygen-to-fuel ratio of the combustible gas mixture supplied to each of the submerged burners, (2) a residence time of the glass melt, and (3) a gas flux through the glass melt.

Both a hydraulic (wet) separation process and a dry separation process are used in combination to recover sand, bentonite clay and organics from foundry waste created during operation of a green sand foundry. These recovered ingredients are then recycled for reuse in making additional green sand molds.