Method for preparing raw materials for glass-making
AssigneeSaint-Gobain Vitrage
InventorPierre Jeanvoine
Life of this patent
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Abstract
The subject of the invention is a process for manufacturing compounds based on one or more silicates of alkali metals, such as Na and K and/or alkaline earth metals such as Ca, Mg, and/or on rare earths, such as Ce, optionally in the form of mixed silicates which combine alkaline-earth metals, such a Ca, with the alkali metal(s) and the rare earth(s), by conversion of silica and of halides, especially of one or more chlorides, or sulfate or nitrate, of the said alkali metals and/or of the said rare earths and/or of the said alkaline-earth metals, such as NaCl, KCl or CeCl4. The heat needed for the conversion is supplied, at least partly, by one or more submerged burners. The subject of the invention is also an apparatus for carrying out the process and for its use.
Claims18
Process for manufacturing compounds based on one or more silicates of alkali metals such as Na, K and/or alkaline-earth metals such as Ca, Mg and/or rare earths such as Ce, optionally in the form of mixed silicates which combine at least two of these elements, by the conversion of silica and of halides or sulfates or nitrates, especially of one or more chlorides, of the said alkali metals and/or of the said rare earth and/or of the said alkaline-earth metals, such as NaCl, KCl or CeCl4, characterized in that the heat necessary for this conversion is supplied, at least partly, by one or more submerged burners.
Process according to either of the preceding claims, characterized in that the submerged burner(s) is(are) fed with a fuel in the form of natural gas, fuel oil or hydrogen and/or in that solid-type or liquid type fuel, especially fuel containing carbon materials based on polymers, possibly chlorinated polymers, or based on coal, is supplied near the said burner(s).
Process according to one of the preceding claims, characterized in that the combustion created by the submerged burner(s) at least partly ensures stirring of the silica and of the halide(s).
Process according to one of the preceding claims, characterized in that the combustion created by the submerged burner(s) at least partly generates the water needed for the conversion.
Process according to one of the preceding claims, characterized in that the conversion also generates halogenated derivatives, especially utilizable chlorinated derivatives such as HCl or Cl2 or H2SO4.
Process according to one of the preceding claims, characterized in that the silicates) formed is(are) treated in order to make it(them) compatible with use as one or more vitrifiable batch materials for a glass furnace, the treatment comprising, in particular, a granulation step.
Apparatus for carrying out the process according to one of the preceding claims, characterized in that it comprises at least one reactor (1) equipped with one or more submerged burners (3) and at least one means for introducing silica and/or the halide(s) or nitrates or sulfates and optionnaly liquid type or solid type combustibles, below the level of the materials undergoing melting, especially in the form of one or more feed-screw batch chargers (6).
Process for obtaining glass containing silica and alkali-metal oxides, of the Na2O or K2O type and/or alkaline-earth metal oxides of the CaO or MgO type and/or rare-earth oxides of the CeO2 type, by melting vitrifiable materials in which the heat needed for the said melting comes at least partly from the submerged burner(s), characterized in that the vitrifiable materials containing alkali metals, of the Na or K type, or rare earths, of the Ce type or alkaline-earth metals, are at least partly in the form of halides, especially chlorides, of the said elements, such as NaCl, KCl or CeCl4.
Dependencies are inferred from the claim text.