A method of fabrication of arsenic glass, comprising forming pellets of an arsenic-containing glass-forming mixture comprising arsenic in a range between about 30 and about 50% w/w and glass forming elements, and melting the pellets by direct heating to a temperature in a range between about 950 and about 1250° C.

A heating tank has a bottom assembly with at least one bottom radiant emitter and a bottom ceramic glass material on an inner surface of the tank, the bottom radiant emitter being configured to deliver infrared energy to the bottom ceramic glass material. The tank has four side assemblies, each of the side assemblies including at least one side radiant emitter and a side ceramic glass material on an inner surface of the tank, the side radiant emitters being configured to deliver infrared energy to the respective side ceramic glass materials. The heating tank can rapidly and efficiently heat materials such as metal and glass.

The invention relates to a process for preparing a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, ii.) Making a glass melt from the silicon dioxide granulate in a melting crucible, and iii.) Making a quartz glass body from at least a part of the glass melt, wherein the melting crucible is comprised in an oven and is made of at least one material comprising tungsten or molybdenum or a combination thereof. The invention further relates to a quartz glass body which can be obtained by this process. Further, the invention relates to a light guide, an illuminant and a formed body, each of which can be obtained by processing the quartz glass body further.

The invention relates to a process for preparing a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, ii.) Making a glass melt from the silicon dioxide granulate in a melting crucible, and iii.) Making a quartz glass body from at least a part of the glass melt, wherein the melting crucible is comprised in an oven and is made of at least one material comprising tungsten or molybdenum or a combination thereof. The invention further relates to a quartz glass body which can be obtained by this process. Further, the invention relates to a light guide, an illuminant and a formed body, each of which can be obtained by processing the quartz glass body further.

The present disclosure provides a solidifying method of a radionuclide. The solidifying method of the radionuclide includes operations of: providing a low melting point glass including Bi.sub.2O.sub.3, B.sub.2O.sub.3, ZnO and SiO.sub.2; providing a glass mixture mixing a mixture to be treated containing a hydroxide of radionuclide and BaSO.sub.4 and the low melting point glass; and heating the glass mixture.

Provided is a method for manufacturing an infrared-transmissive lens having an excellent surface quality. A method for manufacturing an infrared-transmissive lens includes firing a preform of a chalcogenide glass in an inert gas atmosphere to obtain a fired body and then subjecting the fired body to hot press molding.

The present invention provides for synthesizing high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation using a two-zone furnace and multiple fining steps. The top and bottom zones are initially heated to the same temperature, and then a temperature gradient is created between the top zone and the bottom zone. The fining and cooling phase is divided into multiple steps with multiple temperature holds.

The present invention provides for synthesizing high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation using a two-zone furnace and multiple fining steps. The top and bottom zones are initially heated to the same temperature, and then a temperature gradient is created between the top zone and the bottom zone. The fining and cooling phase is divided into multiple steps with multiple temperature holds.

A high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation made using a sealed ampoule with chemical components enclosed inside, a two-zone furnace, a convection heating/mixing step, and multiple fining steps. Initially, the sealed ampoule is oriented vertically within the two-zone furnace and heated to melt the chemical components contained within, and a temperature gradient is created between the top zone and the bottom zone such that the bottom zone has a higher temperature. This temperature gradient causes convection currents within the viscous liquid until it is sufficiently mixed due to the convective flow. Then the temperature gradient is reversed such that the top zone now has a higher temperature and the convective flow ceases. The furnace temperatures are then reduced over a period of time, with holds at multiple temperatures for fining and cooling to form a solid glass.

A high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation made using a sealed ampoule with chemical components enclosed inside, a two-zone furnace, a convection heating/mixing step, and multiple fining steps. Initially, the sealed ampoule is oriented vertically within the two-zone furnace and heated to melt the chemical components contained within, and a temperature gradient is created between the top zone and the bottom zone such that the bottom zone has a higher temperature. This temperature gradient causes convection currents within the viscous liquid until it is sufficiently mixed due to the convective flow. Then the temperature gradient is reversed such that the top zone now has a higher temperature and the convective flow ceases. The furnace temperatures are then reduced over a period of time, with holds at multiple temperatures for fining and cooling to form a solid glass.