Abstract: The invention relates to a method of making a mineral melt comprising providing a circulating combustion chamber (1) which comprises an upper zone (2), a lower zone (3) and a base zone (4), injecting particulate fuel, particulate mineral material and primary combustion gas which has optionally an oxygen level of at least 25% by volume into the upper zone of the circulating combustion chamber so that the fuel undergoes pyrolysis in the upper zone to produce char, thereby melting the particulate mineral materials to form a mineral melt and generating exhaust gases, injecting secondary combustion gas which has optionally an Oxygen level of at least 25% by volume into the lower zone of the circulating combustion chamber so that the char combusts, thereby completing combustion of the fuel, and separating the mineral melt from the hot exhaust gases so that the hot exhaust gases pass though an outlet in the circulating combustion chamber and the mineral melt collects in the base zone.

Abstract: The present invention relates to a method of making mineral fibers, comprising providing a circulating combustion chamber (1) which comprises a top section (2), a bottom section (3) and a base section (4), injecting primary fuel, particulate mineral material and primary combustion gas into the top section of the circulating combustion chamber and combusting the primary fuel thereby melting the particulate material to form a mineral melt and generating exhaust gases, separating the mineral melt from the exhaust gases wherein the exhaust gases pass through an outlet (8) in the circulating combustion chamber and the mineral melt collects in the base section of the circulating combustion chamber, injecting secondary fuel, which comprises liquid or gaseous fuel, and secondary combustion gas into the bottom section of the circulating combustion chamber to form a flame in the bottom section which heats the melt, and flowing a stream of the collected melt through an outlet (15) in the base section to a centrifugal fi

Abstract: Particulate mineral material suitable for forming a fiberisable melt is melted in a flame formed by combustion of powdered carbonaceous fuel with preheated air and the particulate mineral material is then preheated, and the exhaust gases are subjected to NOx reduction, in a cyclone preheater (22).

Abstract: The present invention relates to a method of making mineral fibres, comprising providing a circulating combustion chamber (1) which comprises a top section (2), a bottom section (3) and a base section (4), injecting primary fuel, particulate mineral material and primary combustion gas into the top section of the circulating combustion chamber and combusting the primary fuel thereby melting the particulate material to form a mineral melt and generating exhaust gases, separating the mineral melt from the exhaust gases wherein the exhaust gases pass through an outlet (8) in the circulating combustion chamber and the mineral melt collects in the base section of the circulating combustion chamber, injecting secondary fuel, which comprises liquid or gaseous fuel, and secondary combustion gas into the bottom section of the circulating combustion chamber to form a flame in the bottom section which heats the melt, and flowing a stream of the collected melt through an outlet (15) in the base section to a centrifugal fi

Abstract: The present invention relates to a process for the production of mineral fibers and to an apparatus which can be used in such a process. In particular, the process of the present invention comprises: providing a furnace; charging to the furnace mineral materials which comprise iron oxides; melting the charged mineral materials in a reducing atmosphere, such that there is a base zone in the furnace in which molten iron collects, and a melt pool above the base zone where mineral melt collects; removing mineral melt from the furnace and converting it to mineral fibers; and removing molten iron from the base zone. During the process, an additive is released directly into the base zone of the furnace wherein the additive comprises one or more substances selected from oxidizing agents and non-reducing gases.

Abstract: The invention relates to a method of making a mineral melt comprising providing a circulating combustion chamber (1) which comprises an upper zone (2), a lower zone (3) and a base zone (4), injecting particulate fuel, particulate mineral material and primary combustion gas which has optionally an oxygen level of at least 25% by volume into the upper zone of the circulating combustion chamber so that the fuel undergoes pyrolysis in the upper zone to produce char, thereby melting the particulate mineral materials to form a mineral melt and generating exhaust gases, injecting secondary combustion gas which has optionally an Oxygen level of at least 25% by volume into the lower zone of the circulating combustion chamber so that the char combusts, thereby completing combustion of the fuel, and separating the mineral melt from the hot exhaust gases so that the hot exhaust gases pass though an outlet in the circulating combustion chamber and the mineral melt collects in the base zone.