Abstract: Alkali-resistant glass fibres for use as reinforcement in cementitious products are formed from a composition comprising, in weight percentages:______________________________________ SiO.sub.2 55 to 75% R.sub.2 O 11 to 23% ZrO.sub.2 6 to 22% Cr.sub.2 O.sub.3 0.1 to 1% Al.sub.2 O.sub.3 0.1 to 7% Rare earth oxides + TiO.sub.2 0.5 to 16% ______________________________________where R.sub.2 O is any one or more of Na.sub.2 O, K.sub.2 O or Li.sub.2 O, the content of TiO.sub.2 does not exceed 10%, and the total of the components recited above amounts to at least 88% by weight of the glass, the glass having been melted under non-oxidizing conditions such that all or a substantial proportion of the chromium in the glass is in the trivalent state.Cementitious products incorporating such fibres, e.g. in a proportion of 3 to 6 weight %, can be made using a Magnani-type asbestos cement machine or by a "spray-up" method.

Abstract: A range of borosilicate glass compositions which are capable of sealing effectively to nickel iron alloys containing up to approximately 52% nickel to form a hermetic seal resistant to thermal shock breakage. The glass is in the composition range percent by weight of:SiO.sub.2 : 55-66Al.sub.2 O.sub.3 : 4.5-10Na.sub.2 O: 0-4K.sub.2 O: 3.5-7B.sub.2 O.sub.3 : 19.0-26.0TiO.sub.

Abstract: This invention is directed to the production of glazes exhibiting an earthenware appearance which are particularly suitable for decorating ceramic dinnerware. The glaze composition consists essentially of about 4-8% by weight SnO.sub.2 and 4-8% by weight TiO.sub.2, the total SnO.sub.2 +TiO.sub.2 being about 10-14%, and about 0.025-0.04% by weight MnO.sub.2 incorporated into a base frit consisting essentially, as analyzed in weight percent on the oxide basis, of about______________________________________ SiO.sub.2 37-49 Al.sub.2 O.sub.3 4-7 B.sub.2 O.sub.3 6.5-11 ZrO.sub.2 0-1.75 Na.sub.2 O 1.75-3.5 K.sub.2 O 0.75-2.5 PbO 21-32 CdO 0-0.75 CaO 1-9 TiO.sub.2 0-0.35 F 0-0.6 ______________________________________The fired glaze contains crystallites of rutile and cassiterite.

Abstract: The instant invention is concerned with the production of spontaneous opal glasses exhibiting tints ranging from ivory-through-beige-through-tan-to-brown, depending upon the shade sought, and demonstrating a Fe.sup.+3 reading between about 6.5-9 consisting essentially, expressed in weight percent on the oxide basis, of about______________________________________ SiO.sub.2 64.5 .+-. 2.0 Al.sub.2 O.sub.3 6.25 .+-. 0.5 Na.sub.2 O 3.0 .+-. 0.5 K.sub.2 O 3.0 .+-. 0.5 MgO 1.25 .+-. 0.3 B.sub.2 O.sub.3 4.5 .+-. 0.7 F 3.25 .+-. 0.5 CaO 14.5 .+-. 1.0 NiO 0.02 - 1.

Abstract: Alkali-resistant glass fibres, in the form of continuous-filament for use as reinforcement in cementitious products, or in the form of glass wool, are given enhanced alkali resistance by the incorporation of ThO.sub.2. The fibres are formed from a glass composition comprising, in weight percentages:______________________________________ SiO.sub.2 50 to 75% ThO.sub.2 + ZrO.sub.2 5 to 30% with ThO.sub.2 at least 0.4% R.sub.2 O 0 to 25% R'O 0 to 40% R.sub.2 O + R'O 10 to 40% Rare earth oxides 0 to 20% ______________________________________the content of ThO.sub.2 being at least 1% when the content of ZrO.sub.2 is less than 6% but not exceeding 9.5% when ZrO.sub.2 exceeds 8%, where R.sub.2 O represents Na.sub.2 O, K.sub.2 O or LiO.sub.2, with K.sub.2 O not exceeding 10% and Li.sub.2 O not exceeding 5% and R'O represents one or more of MgO, CaO, SrO, BaO, ZnO and MnO.

Abstract: The instant invention is directed to the production of spontaneous opal glass compositions which limit the generation of CaF.sub.2 and crystals having a xonotlite structure therein when heat treated at temperatures higher than the annealing point, but lower than the softening point of the glass. The glasses consist essentially, as analyzed in weight percent on the oxide basis, of about:______________________________________ SiO.sub.2 64.5 .+-. 2.0 Al.sub.2 O.sub.3 6.25 .+-. 0.5 Na.sub.2 O 3.0 .+-. 0.5 K.sub.2 O 3.0 .+-. 0.5 MgO 1.25 .+-. 0.3 B.sub.2 O.sub.3 4.5 .+-. 0.7 F 3.25 .+-. 0.5 CaO 14.5 .+-. 1.

Abstract: Disclosed are various ceramic frits which have a unique combination of low solubility, low-melting temperature, and freedom from lead oxide. They are formed from selected compositions in the alkali--ZnO--Al.sub.2 O.sub.3 --B.sub.2 O.sub.3 --P.sub.2 O.sub.5 --SiO.sub.2 --TiO.sub.2 --F system.

Abstract: The present invention is concerned with the production of spontaneous opal glasses which, after thermal tempering, demonstrate a dense coloration ranging from ivory through yellow-beige to tan to a grayish-brown appearance, consisting essentially, by weight on the oxide basis, of 8-9% Na.sub.2 O, 2-2.5% K.sub.2 O, 5-6.5% CaO, 8-10% ZnO, 1-2% B.sub.2 O.sub.3, 10-11% Al.sub.2 O.sub.3, 3-4% F, 0.005-0.1% NiO, 0-2% CeO.sub.2, 0-4%TiO.sub.2, 0.5-6% CeO.sub.2 +TiO.sub.2, 0-0.5% As.sub.2 O.sub.3, and 57-61% SiO.sub.2.

Abstract: This invention is directed to the production of spontaneous essentially non-crystalline opal glasses exhibiting a very dense, milky-white appearance and excellent resistance to weathering and attack by alkaline detergents consisting essentially, expressed in weight percent on the oxide basis, of 2-5% K.sub.2 O, 4-10% Na.sub.2 O, 4.5-12% RO, wherein RO consists of 0-3% MgO, 0-6% CaO, 0-8% SrO, and 0-11% BaO, 4-9% B.sub.2 O.sub.3, 6-15% Al.sub.2 O.sub.3, 0-5% TiO.sub.2, 51-66% SiO.sub.2, 1-6% P.sub.2 O.sub.5, and 1-5% F.