Mineral wool

A method of making mineral wool fibers,

• wherein the mineral wool fibers comprise:
• 30 to 55 wt % SiO2, and
• 10 to 30 wt % Al2O3, and
• 4 to 14 wt % total iron expressed as Fe2O3, and
• either a) 20 to 35 wt % of the combination of CaO and MgO;
• and less than 8 wt % of the combination of Na2O and K2O;
• or b) 8 to 23 wt % of the combination of CaO and MgO;
• and 4 to 24 wt % of the combination of Na2O and K2O;
• the method comprising:
• introducing mineral batch materials in to a melter, melting the mineral batch materials to provide a melt and fiberizing the melt to form the mineral wool fibers,
• wherein the mineral batch materials introduced in to the melter comprise a first batch material and one or more further batch materials, wherein the first batch material comprises:
• 52 to 68 wt % SiO2, and
• 12 to 30 wt % Al2O3, and
• 0 to 25 wt % CaO, and
• 0 to 12 wt % MgO, and
• 0 to 10 wt % B2O3, and
• 0 to 2 wt % of the combination of Li2O+Na2O+K2O, and
• 0 to 1.5 wt % TiO2, and
• 0.05 to 1 wt % total iron expressed as Fe2O3, and
• 0 to 1 wt % fluoride;
• spraying an aqueous binder solution to coat the mineral wool fibers while the mineral wool fibers are being carried in an air stream;
• collecting the binder coated mineral wool fibers to form a blanket of mineral wool fibers;
• and
• curing the aqueous binder solution by passing the blanket of mineral wool fibers through a curing oven.