The present invention relates to a cement additive and a method for producing same, wherein carcinogens, including heavy metals such as hexavalent chromium and the like, generated from cement are removed while maintaining the strength and characteristic physical properties of cement. Moreover, the cement additive according to the present invention can provide cement that does not become oxidized by heat into hexavalent chromium.

A glass furnace including an additive-containing product including an additive selected from: phosphorus compounds other than glasses and vitroceramics, tungsten compounds other than glasses and vitroceramics, molybdenum compounds other than glasses and vitroceramics, iron in the form of metal, aluminum in the form of metal, silicon in the form of metal, and their mixtures, silicon carbide, boron carbide, silicon nitride, boron nitride, glasses including elemental phosphorus and/or iron and/or tungsten and/or molybdenum, vitroceramics including elemental phosphorus and/or iron and/or tungsten and/or molybdenum, and their mixtures, and having the following chemical analysis, exclusively of the additive, as a percentage by weight on the basis of the oxides: Cr.sub.2O.sub.32%, and Cr.sub.2O.sub.3+Al.sub.2O.sub.3+CaO+ZrO.sub.2+MgO+Fe.sub.2O.sub.3+SiO.sub.2+TiO.sub.290%, and Cr.sub.2O.sub.3+Al.sub.2O.sub.3+MgO60%, the content by weight of additive being in the range 0.01% to 6%.

The present invention relates to a cement additive and a method for producing same, wherein carcinogens, including heavy metals such as hexavalent chromium and the like, generated from cement are removed while maintaining the strength and characteristic physical properties of cement. Moreover, the cement additive according to the present invention can provide cement that does not become oxidized by heat into hexavalent chromium.

A glass furnace including an additive-containing product including an additive selected from: phosphorus compounds other than glasses and vitroceramics, tungsten compounds other than glasses and vitroceramics, molybdenum compounds other than glasses and vitroceramics, iron in the form of metal, aluminum in the form of metal, silicon in the form of metal, and their mixtures, silicon carbide, boron carbide, silicon nitride, boron nitride, glasses including elemental phosphorus and/or iron and/or tungsten and/or molybdenum, vitroceramics including elemental phosphorus and/or iron and/or tungsten and/or molybdenum, and their mixtures, and having the following chemical analysis, exclusively of the additive, as a percentage by weight on the basis of the oxides: Cr.sub.2O.sub.3?2%, and Cr.sub.2O.sub.3+Al.sub.2O.sub.3+CaO+ZrO.sub.2+MgO+Fe.sub.2O.sub.3+SiO.sub.2+TiO.sub.2?90%, and Cr.sub.2O.sub.3+Al.sub.2O.sub.3+MgO?60%, the content by weight of additive being in the range 0.01% to 6%.

Methods of producing cement using a spent hydrocarbon dehydrogenation catalyst are disclosed. A spent hydrocarbon dehydrogenation catalyst comprising alumina is processed to produce a processed raw material. The processed raw material is then used as a component for producing the cement. Compositions of cement including the processed raw material are disclosed.

A method and Bridge in a Provider Backbone Bridge Network, PBBN, for enabling frames from a Higher Layer Entity attached alternatively to a Provider Instance Port on an I-Component of a Backbone Edge Bridge or to a Customer Backbone Port on a B-Component of the Backbone Edge Bridge, to reach an intended entity in the PBBN. A Virtual Instance Port Service Access Point, VIP SAP, is configured for every VIP and every Higher Layer Entity configured on the I-Component. An Enhanced VIP Port Connectivity function utilizes the VIP SAP to tunnel customer-initiated Layer 2 Control Protocols, L2CPs. A Special Multiplexed SAP handles the frames of the Higher Layer Entity, and is assigned an I-SID value that is universally recognized to identify the L2CPs. A Service Instance Multiplex Entity utilizes the Special Multiplexed SAP to transfer frames between the Provider Instance Port or the Customer Backbone Port and the entity inside the PBBN.