MINERAL WOOL

Abstract

A method of making mineral wool fibers comprising:

30 to 55 wt %; SiO.sub.2, and
10 to 30 wt % Al.sub.2O.sub.3, and
4 to 14 wt % total iron expressed as Fe.sub.2O.sub.3, and
either a) 20 to 35 wt % of the combination of CaO and MgO; and less than 8 wt % of the combination of Na.sub.2O and K.sub.2O; or b) 8 to 23 wt % of the combination of CaO and MgO; and 4 to 24 wt % of the combination of Na.sub.2O and K.sub.2O;
comprises 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. The mineral batch materials introduced in to the melter comprise a first batch material comprising:
52 to 68 wt % SiO.sub.2, notably 52 to 62 wt % SiO.sub.2, and
12 to 30 wt % Al.sub.2O.sub.3, notably 12 to 16 wt % Al.sub.2O.sub.3, and
0 to 25 wt % CaO, notably 16 to 25 wt % CaO, and
0 to 12 wt % MgO, notably 0 to 5 wt % MgO, and
0 to 10 wt % B.sub.2O.sub.3, notably 0 to 2 wt % B.sub.2O.sub.3, and
0 to 2 wt % of the combination of Li.sub.2O+Na.sub.2O+K.sub.2O, and
0 to 1.5 wt % TiO.sub.2, and
0.05 to 1 wt % total iron expressed as Fe.sub.2O.sub.3, and
0 to 1 wt % fluoride.

Claims

1.-15. (canceled)

16. A method of making mineral wool fibers comprising: 30 to 55 wt % SiO.sub.2, and 10 to 30 wt % Al.sub.2O.sub.3, and 4 to 14 wt % total iron expressed as Fe.sub.2O.sub.3, and a combination selected from: a) 20 to 35 wt % of the combination of CaO and MgO; and less than 8 wt % of the combination of Na.sub.2O and K.sub.2O; and b) 8 to 23 wt % of the combination of CaO and MgO; and 4 to 24 wt % of the combination of Na.sub.2O and K.sub.2O; 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 comprising: 52 to 68 wt % SiO.sub.2, and 12 to 30 wt % Al.sub.2O.sub.3, and 0 to 25 wt % CaO, and 0 to 12 wt % MgO, and 0 to 10 wt % B.sub.2O.sub.3, and 0 to 2 wt % of the combination of Li.sub.2O+Na.sub.2O+K.sub.2O, and 0 to 1.5 wt % TiO.sub.2, and 0.05 to 1 wt % total iron expressed as Fe.sub.2O.sub.3, and 0 to 1 wt % fluoride.

17. The method of claim 16 wherein the first batch material comprises 52 to 62 wt % SiO.sub.2.

18. The method of claim 16 wherein the first batch material comprises 12 to 16 wt % Al.sub.2O.sub.3.

19. The method of claim 16 wherein the first batch material comprises 16 to 25 wt % CaO.

20. The method of claim 16 wherein the first batch material comprises 0 to 5 wt % MgO.

21. The method of claim 16 wherein the first batch material comprises 0 to 2 wt % B.sub.2O.sub.3.

22. The method of claim 16 wherein the first batch material comprises: 52 to 62 wt % SiO.sub.2, and 12 to 16 wt % Al.sub.2O.sub.3, and 16 to 25 wt % CaO, and 0 to 5 wt % MgO, and 0 to 10 wt % B.sub.2O.sub.3, and 0 to 2 wt % of the combination of Li.sub.2O+Na.sub.2O+K.sub.2O, and 0 to 1.5 wt % TiO.sub.2, and 0.05 to 1 wt % total iron expressed as Fe.sub.2O.sub.3, and 0 to 1 wt % fluoride.

23. The method of claim 22 wherein the first batch material comprises 52 to 56 wt % SiO.sub.2.

24. The method of claim 16 wherein the first batch material comprises fibers.

25. The method of claim 17 wherein the fibers comprise an organic coating present in a quantity of at least 2 wt % with respect to the total weight of the first batch material.

26. The method of claim 16 wherein the first batch material comprises less than 0.01 wt % B.sub.2O.sub.3.

27. The method of claim 16 wherein the first batch material constitutes between 10 to 60 wt % of the mineral batch materials.

28. The method of claim 16 wherein the melter is selected from a submerged combustion melter, a cupola furnace, an electric arc furnace and a circulating furnace.

29. The method of claim 16 wherein the first batch material comprises loose fibers.

30. The method of claim 16 wherein the moisture content of the first batch material when introduced in to the melter is at least 10 wt %.

31. The method of claim 16, wherein the first batch material comprises briquettes comprising fibers of the first batch material.

32. The method of claim 16 wherein the first batch material comprises fibers derived from the manufacture of continuous fibers.

33. The method of claim 16 wherein the mineral batch materials comprises a second batch material comprising fibers comprising: 30 to 55 wt %; SiO.sub.2, and 10 to 30 wt % Al.sub.2O.sub.3, and 20 to 35 wt % of the combination of CaO and MgO, and 4 to 10 wt % total iron expressed as Fe.sub.2O.sub.3, and less than 8 wt % of the combination of Na.sub.2O and K.sub.2O, and an alkali/alkaline-earth ratio which is <1.

34. The method of claim 16 wherein the mineral batch materials comprise further batch materials selected from: dolomite, calcined bauxite, steel slag and combinations thereof.

35. The method of claim 16 further comprising making a mineral wool insulation product from the mineral wool fibers by; spraying an aqueous binder solution to coat the mineral wool fibers whilst the mineral wool fibers are being carried in an air stream; collecting the binder coated mineral wool fibers to form a blanket of mineral fibers; and curing the aqueous binder solution by passing the blanket of mineral wool fibers through a curing oven.

36. The method of claim 35, in which the batch materials comprise recycled portions of the mineral wool insulation product.

Description

EXAMPLE 1

[0085] The following mineral batch materials were melted in a laboratory melter:

27 wt % of a first batch material in the form of fibers;
50 wt % of a second batch material in the form of fibers;
10 wt % crushed dolomite (batch material 3);
9 wt % crushed steel slag (batch material 4);
4 wt % crushed calcined bauxite (batch material 5);
where
a) the wt % above is expressed in relation to the total weight of the combination of all of the mineral batch materials;
b) the first batch material consisted of about: 60.1 wt % SiO.sub.2, 13.2 wt % Al.sub.2O.sub.3, 22.1 wt % CaO, 3.1 wt % MgO, less than 0.1 wt % B.sub.2O.sub.3, less than 0.1 wt % Li.sub.2O, 0.9 wt % Na.sub.2O, less than 0.1 wt % K.sub.2O, 0.5 wt % TiO.sub.2, and less than 0.1 wt % total iron expressed as Fe.sub.2O.sub.3;
c) the second batch material consisted of about: 40.2 wt %; SiO.sub.2, 17.3 wt % Al.sub.2O.sub.3, 18.5 wt % CaO, 10.6 wt % MgO, 7.8 wt % total iron expressed as Fe.sub.2O.sub.3, 2.1 wt % Na.sub.2O, 0.8 wt % K.sub.2O, 1.5 wt % TiO.sub.2 and 0.2 wt % P.sub.2O.sub.3.

[0086] The batch materials were sequentially: dried at 105 C.; crushed in a vibratory mill; mixed in a rotary mixer; and melted in an electric furnace at 1450 C. for 4 hours in alumina crucibles.

[0087] The composition of the melt produced comprised about: 41.3 wt % SiO.sub.2, 18.8 wt % Al.sub.2O.sub.3, 21.5 wt % CaO, 9.1 wt % MgO, 6.2 wt % total iron expressed as Fe.sub.2O.sub.3, 1.5 wt % Na.sub.2O, 0.5 wt % K.sub.2O, 1.2 wt % TiO.sub.2 and 0.1 wt % P.sub.2O.sub.3. It had a log 3 viscosity permitting fiberization on a cascade spinner and a bio-solubility satisfying the requirements of Note Q.

[0088] The first batch material had a composition significantly different from the composition of the melt produced. For example, the first batch material had:

[0089] a quantity of SiO.sub.2 which was greater than that of the melt produced by 18.8 percentage points (ie 60.1 wt % minus 41.3 wt %);

[0090] a quantity of Al.sub.2O.sub.3 which was less than that of the melt produced by 5.6 percentage points (ie 18.8 wt % minus 13.2 wt %);

[0091] a quantity of CaO which was greater than that of the melt produced by 0.6 percentage points (ie 22.1 wt % minus 21.5 wt %);

[0092] a quantity of MgO which was less than that of the melt produced by 6 percentage points (ie 9.1 wt % minus 3.1 wt %); and

[0093] a quantity of total iron expressed as Fe.sub.2O.sub.3 which was less than that of the melt produced by 6.1 percentage points (ie 6.2 wt % minus 0.1 wt %).

EXAMPLE 2

[0094] A melt having the following composition: 52.0 wt % SiO.sub.2, 15.1 wt % Al.sub.2O.sub.3, 13.0 wt % CaO, 6.0 wt % MgO, 1.6 wt % TiO.sub.2, 7.4 wt % total iron expressed as Fe.sub.2O.sub.3, 2.6 wt % Na.sub.2O, 1.5 wt % K.sub.2O, 0.4 wt % F, 0.1 wt % Mn.sub.2O.sub.3 and 0.4 wt % P.sub.2O.sub.5, and which is suitable for fiberizing may be obtained by melting the following quantity of batch materials, notably in a submerged combustion melter:

40 wt % of scrap fibers (batch material 1);
2 wt % steel slag (batch material 2);
58 wt % basalt (batch material 3);
wherein Table 1 below give the composition of the batch materials in wt %. The quantities in Table 1 are expressed when fully calcined; the loss represents primarily decarboxylation of calcinates and loss of water of crystallization

TABLE-US-00001 TABLE 1 composition of batch materials in wt % SiO.sub.2 Al.sub.2O.sub.3 CaO MgO TiO.sub.2 Fe.sub.2O.sub.3 Na.sub.2O K.sub.2O F Mn.sub.2O.sub.3 P.sub.2O.sub.5 Loss Batch material 1 59.5 15.0 18.0 3.0 1.0 0.5 1.5 0.5 1.0 Scrap fibers Batch material 2 11.3 5.3 22.8 5.6 47.2 6.7 0.6 0.5 Steel slag Batch material 3 48.1 15.4 9.2 8 2.1 10.7 3.4 2.2 0.7 0.2 Basalt

[0095] As it can be seen, the first batch material has a composition significantly different from the composition of the melt or mineral fibers produced.