The invention provides a composition for glass, a glass, and a preparation method and application thereof. On an oxide basis, the composition for glass contains 45-64 wt % SiO.sub.2, 16-26 wt % Al.sub.2O.sub.3, 0.1-2 wt % MgO, 10-17 wt % Na.sub.2O, 0.5-15 wt % P.sub.2O.sub.5, and optionally 0-2 wt % TiO.sub.2. The glass prepared from the composition for glass has a higher chemical resistance, a higher strain point, and a higher compressive stress and depth of compressive stress layer formed on the glass surface, and the glass has a higher Young's modulus.

The invention provides a composition for glass, a glass, and a preparation method and application thereof. On an oxide basis, the composition for glass contains 45-64 wt % SiO.sub.2, 16-26 wt % Al.sub.2O.sub.3, 0.1-2 wt % MgO, 10-17 wt % Na.sub.2O, 0.5-15 wt % P.sub.2O.sub.5, and optionally 0-2 wt % TiO.sub.2. The glass prepared from the composition for glass has a higher chemical resistance, a higher strain point, and a higher compressive stress and depth of compressive stress layer formed on the glass surface, and the glass has a higher Young's modulus.

One aspect relates to a process for the preparation of a quartz glass body, including providing a silicon dioxide granulate, wherein the silicon dioxide granulate was made from pyrogenic silicon dioxide powder and the silicon dioxide granulate has a BET surface area in a range from 20 to 40 m.sup.2/g, making a glass melt out of silicon dioxide granulate in an oven and making a quartz glass body out of at least part of the glass melt. The oven has at least a first and a further chamber connected to one another via a passage. The temperature in the first chamber is lower than the temperature in the further chambers. On aspect relates to a quartz glass body which is obtainable by this process. One aspect relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing of the quartz glass body.

The present invention relates to a silver coated glass frit used in a paste composition for forming a solar cell electrode, a method for preparing the same, and a silver paste composition using a silver coated glass frit for a solar cell. More specifically, the present invention relates to: a method for preparing a silver-coated glass frit wherein a silver coated glass frit, in which silver (Ag) is coated on a surface of the glass frit, is prepared through a reduction reaction occurring by adding, to a first solution containing silver nitrate (AgNO3) mixed with a glass frit and an amine, a second solution containing a reductant, and during the preparation process, a silver (Ag) coating layer is more uniformly formed on the surface of the glass frit by controlling the acidity of the first solution and the reaction temperature in the reduction reaction, thereby achieving an improved specific surface area; a silver-coated glass frit prepared by the method; and a silver paste composition for a solar cell wherein the composition is prepared by using the sliver-coated glass frit, and thus has significantly improved sintering characteristics and electrical conductivity.

The present invention relates to a silver coated glass frit used in a paste composition for forming a solar cell electrode, a method for preparing the same, and a silver paste composition using a silver coated glass frit for a solar cell. More specifically, the present invention relates to: a method for preparing a silver-coated glass frit wherein a silver coated glass frit, in which silver (Ag) is coated on a surface of the glass frit, is prepared through a reduction reaction occurring by adding, to a first solution containing silver nitrate (AgNO3) mixed with a glass frit and an amine, a second solution containing a reductant, and during the preparation process, a silver (Ag) coating layer is more uniformly formed on the surface of the glass frit by controlling the acidity of the first solution and the reaction temperature in the reduction reaction, thereby achieving an improved specific surface area; a silver-coated glass frit prepared by the method; and a silver paste composition for a solar cell wherein the composition is prepared by using the sliver-coated glass frit, and thus has significantly improved sintering characteristics and electrical conductivity.

Methods and systems for treating mined sand to remove an impurity in accordance with the disclosure. An example method mined sand provides mined sand containing the impurity, contacting the mined sand with an aqueous treatment fluid comprising an ethoxylated alcohol and a sulfonic acid derivative, and drying the mined sand; wherein at least a portion of the impurity is removed from the dried mined sand after contact of the mined sand with the aqueous treatment fluid.

The invention relates to a process for the preparation of a glass-ceramic blank for dental purposes with lithium silicate as crystal phase, in which lithium silicate blanks that are no longer required and in particular residues thereof are used as starting material and which allows the production of a homogeneous starting glass within a short time.

One aspect relates to a process for the preparation of a quartz glass body. The process includes providing silicon dioxide particles, making a glass melt out of the silicon dioxide particles in an oven and making a quartz glass body out of at least part of the glass melt. The oven has a gas outlet through which gas is removed from the oven, wherein the dew point of the gas on exiting the oven through the gas outlet is less than 0° C. One aspect further relates to a quartz glass body which is obtainable by this process. One aspect further relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing of the quartz glass body.

One aspect relates to a process for the preparation of a quartz glass body including, providing a silicon dioxide granulate obtainable from a silicon dioxide powder, wherein the silicon dioxide granulate has a larger particle size than the silicon dioxide powder, making a 5 glass melt out of silicon dioxide granulate and making a quartz glass body out of at least part of the glass melt. The melting crucible has at least one inlet and at least one outlet. A least part of the glass melt is removed via the melting crucible outlet. One aspect further relates to a quartz glass body which is obtainable by this process. One aspect further relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing 10 of the quartz glass body.

A method for producing glass by removing coloring ions through reduction is described, as are products obtained by this method.