The present invention relates to a process for producing a boron containing glass, comprising melting raw materials including boron compounds in a submerged combustion melter (11), withdrawing flue gases from said melter and recovering heat from said flue gases in appropriate heat recovery equipment prior to release into the environment.

The present invention relates to a process for producing a boron containing glass, comprising melting raw materials including boron compounds in a submerged combustion melter (11), withdrawing flue gases from said melter and recovering heat from said flue gases in appropriate heat recovery equipment prior to release into the environment.

The invention provides methods of making man-made vitreous fibres (MMVF), comprising incorporating metallic aluminium into the mineral charge, with the benefit of reduced shrinkage of consolidated MMVF products.

The invention provides methods of making man-made vitreous fibres (MMVF), comprising incorporating metallic aluminium into the mineral charge, with the benefit of reduced shrinkage of consolidated MMVF products.

The invention provides a method to form a melt for making man-made vitreous fibres, in which mineral raw material is melted in a gas-fired cyclone furnace and the mineral charge comprises a material that comprises metallic aluminium.

The invention provides a method to form a melt for making man-made vitreous fibres, in which mineral raw material is melted in a gas-fired cyclone furnace and the mineral charge comprises a material that comprises metallic aluminium.

A submerged combustion melter is arranged with a melting chamber, which may be cylindrical, and at least five submerged combustion burners.

A submerged combustion melter is arranged with a melting chamber, which may be cylindrical, and at least five submerged combustion burners.

The invention relates to a method of making a mineral melt, the method comprising providing a circulating combustion chamber which comprises an upper zone, a lower zone and a base zone, injecting primary particulate fuel and particulate mineral material and primary combustion gas into the upper zone of the circulating combustion chamber, thereby at least partially combusting the primary particulate fuel and thereby melting the particulate mineral material to form a mineral melt and generating exhaust gases, injecting into the lower zone of the circulating combustion chamber, through at least one first burner, secondary combustion gas and gaseous fuel and secondary particulate fuel, wherein the secondary combustion gas and gaseous fuel and secondary particulate fuel are injected via a single first burner, wherein the amount of secondary combustion gas injected via each first burner is insufficient for stoichiometric combustion of the total amount of gaseous fuel and secondary particulate fuel injected via that first burner, and injecting tertiary combustion gas into the lower zone of the circulating combustion chamber, through at least one tertiary combustion gas injector, whereby the tertiary combustion gas enables completion of the combustion of the gaseous fuel and the secondary particulate fuel, separating the mineral melt from the hot exhaust gases so that the hot exhaust gases pass through an outlet in the circulating combustion chamber and the mineral melt collects in the base zone. The invention also relates to apparatus suitable for use in the method.

The invention relates to a method of making a mineral melt, the method comprising providing a circulating combustion chamber which comprises an upper zone, a lower zone and a base zone, injecting primary particulate fuel and particulate mineral material and primary combustion gas into the upper zone of the circulating combustion chamber, thereby at least partially combusting the primary particulate fuel and thereby melting the particulate mineral material to form a mineral melt and generating exhaust gases, injecting into the lower zone of the circulating combustion chamber, through at least one first burner, secondary combustion gas and gaseous fuel and secondary particulate fuel, wherein the secondary combustion gas and gaseous fuel and secondary particulate fuel are injected via a single first burner, wherein the amount of secondary combustion gas injected via each first burner is insufficient for stoichiometric combustion of the total amount of gaseous fuel and secondary particulate fuel injected via that first burner, and injecting tertiary combustion gas into the lower zone of the circulating combustion chamber, through at least one tertiary combustion gas injector, whereby the tertiary combustion gas enables completion of the combustion of the gaseous fuel and the secondary particulate fuel, separating the mineral melt from the hot exhaust gases so that the hot exhaust gases pass through an outlet in the circulating combustion chamber and the mineral melt collects in the base zone. The invention also relates to apparatus suitable for use in the method.