Patent ID: 11945745
Assignee: KNAUF INSULATION SPRL
Field: Materials, metallurgy (Chemistry)
Classification: CPC C | IPC C

Claim 0:
1. A method of making mineral wool fibers comprising:
55 to 75 wt % SiO2, and
5 to 20 wt % of the combination of CaO and MgO, and
5 to 20 wt % of the combination of Na2O and K2O, and
0 to 5 wt % Al2O3, and
up to 2 wt % total iron expressed as Fe2O3, and
an alkali/alkaline-earth ratio expressed in terms of wt % of alkali metal oxides/wt % of alkaline-earth metal oxides which is >1,
the method comprising:
introducing mineral batch materials in to a melter, the mineral batch materials comprising a first batch material and a second batch material, and melting the mineral batch materials to provide a melt and fiberizing the melt to form the mineral wool fibers,
wherein
the first batch material consists essentially of scrap from the manufacture of mineral fibers and which comprises:
52 to 62 wt % SiO2, and
12 to 16 wt % Al2O3, and
16 to 25 wt % CaO, and
0 to 5 wt % MgO, and
4 to 10 wt % B2O3, and
0 to 2 wt % of the combination of Li2O+Na2O+K2O, and
0 to 1.5 wt % TiO2, and
0.005 to 1 wt % total iron expressed as Fe2O3, and
0 to 1 wt % fluoride.