Abstract: The invention relates to brownish, brown to black colored borosilicate glasses which have stepped grades of transmission in the NIR range or are fully non-transmitting. The borosilicate glass, primarily the borosilicate glass 3.3, is melted with defined additives of titanium carbide and/or metallic silicon. The glasses produced in accordance with the invention are to be used as filters, glass vessels and/or decorative colored glass in construction and for decorating because of their absorption/transmission characteristics. On the other hand, the glasses produced in accordance with the invention can also be used as absorbers in solar technology when the light transmissibility in the NIR/IR range is sufficiently low.

Abstract: Borosilicate glass weak in boric acid having a high chemical stability with an alkali resistance according to DIN 52 322 of LBK-Class 1, a thermal expansion .alpha..sub.20/300 between 4.0 to 5.3.times.10.sup.-6 K.sup.-1, a ratio .alpha.'/.alpha. of thermal expansion coefficients above T.sub.g (.alpha.') to below T.sub.g (.alpha.) of 4 to 8, a glass transformation temperature between 500.degree. C. and 600.degree. C., high radiation transmittance and a UV transmission .tau..sub.250 nm/1 mm of 0 to 70% or .tau..sub.300 nm/1 mm of 0 to 91% of the composition in percent by weight on oxide basis of: SiO.sub.2 >75; B.sub.2 O.sub.3 1 to <9; Al.sub.2 O.sub.3 3 to 6; Li.sub.2 O 0 to 4; Na.sub.2 O 0 to 8; K.sub.2 O 0 to 6; MgO 0 to 3; CaO 0 to 3; BaO 0 to 2; SrO 0 to 2; ZnO 0 to 3; ZrO.sub.2 0 to 3; SnO.sub.2 0 to 3; SnO 0 to 3; TiO.sub.2 0 to 2; CeO.sub.2 0 to 2; Fe.sub.2 O.sub.3 0 to 1; with SiO.sub.2 +B.sub.2 O.sub.3 >83; SiO.sub.2 :B.sub.2 O.sub.3 >8; SiO.sub.2 +Al.sub.2 O.sub.3 +ZrO.sub.2 >83; Li.

Abstract: An apparatus for decomposing difficultly soluble substances and oxidizing organic wastes which contain difficultly soluble substances, in which the substances and/or wastes are reacted with at least one hot acid, and from apparatus which heat losses are compensated. The apparatus comprises a ring-shaped reaction vessel including at least one horizontally extending region and at least one vertically extending region. A feeder is connected to the vertically extending region for the addition to the reaction vessel of substances and/or wastes, acid, and gas. A degasificaton zone is connected to the horizontally extending region.