Method of Producing a Gypsum Slurry for Forming Gypsum Products and Method of Manufacturing a Gypsum Product

Abstract

A method of producing a gypsum slurry for forming gypsum products, in particular gypsum boards, preferably gypsum paper boards, comprising the steps of: a) providing a gypsum paper product comprising a gypsum and a paper component, in particular a gypsum paper board, and/or broken parts thereof; b) wet grinding the gypsum paper product and/or the broken parts thereof containing at least parts of the paper component to form a wet ground gypsum paper component.

Claims

1. A method of producing a gypsum slurry for forming gypsum products, in particular gypsum boards, preferably gypsum paper boards or gypsum fibre board, comprising the steps of: a) providing a gypsum paper product comprising a gypsum and a paper component, in particular a gypsum paper board, and/or broken parts thereof; and b) wet grinding the gypsum paper product and/or the broken parts thereof containing at least parts of the paper component to form a wet ground gypsum paper component.

2. The method of claim 1, characterised by mixing the wet ground gypsum paper component with stucco.

3. The method of claim 1, characterised in that step b) comprises forming a paper gypsum slurry containing water, paper particles, in particular paper fibres, and gypsum, in particular gypsum powder.

4. The method of claim 1, characterised in that the paper gypsum slurry has a solid content between 2 wt % and 50 wt %, preferably between 5 wt % and 30 wt %, further preferably between 15 wt % and 20 wt %.

5. The method of claim 3, characterised in that the gypsum paper slurry is fed into a container, in particular silo, and preferably stirred therein, in particular before mixing it with stucco.

6. The method of claim 2, characterised in that the solid content of the wet ground gypsum paper component, in particular gypsum paper slurry, with respect to the stucco is between 0.5 wt % and 10 wt %, preferably between 1 wt % and 5 wt %, further preferably between 2 wt % and 4 wt %.

7. The method of claim 1, characterised in that the broken parts are obtained by shredding the gypsum paper product.

8. The method of claim 1, characterised in that the wet ground gypsum paper product is not calcined.

9. A method of manufacturing a gypsum product, in particular gypsum board, preferably gypsum paper board comprising the method of producing a gypsum slurry of claim 1 and comprising removing water from the gypsum slurry and forming the gypsum product.

10. The method of claim 9, characterised in that the wet ground gypsum paper product is not calcined.

11. A use of a wet ground gypsum paper component as ingredient of a gypsum slurry for forming a gypsum product, in particular gypsum board, preferably gypsum paper board or gypsum fibre board.

12. A gypsum slurry for forming gypsum products, in particular gypsum boards, preferably gypsum paper boards or gypsum fibre boards, produced by the method of claim 1.

13. A gypsum product, in particular gypsum board, preferably gypsum paper board or gypsum fibre board, produced by the method of claim 1.

14. A system for producing a gypsum slurry for forming gypsum products, in particular gypsum boards, preferably gypsum paper boards or gypsum fibre boards, comprising: a mill for wet grinding a gypsum paper product comprising a gypsum and a paper component, in particular gypsum paper board, and/or broken parts thereof to a wet ground gypsum paper component; a first feeding device for feeding the wet ground gypsum paper component to a mixer; and a second feeding device for feeding further components, in particular stucco to the mixer for mixing the slurry for forming gypsum products.

15. A system for manufacturing a gypsum product, in particular gypsum board, preferably gypsum paper board or gypsum fibre board, comprising the system for producing the gypsum slurry of claim 14 and a forming device for forming the gypsum product, in particular gypsum board, preferably gypsum paper board or gypsum fibre board.

Description

[0033] In the following, a preferred embodiment of the invention is described with reference to the following drawing:

[0034] FIG. 1: A schematic of a method of producing a gypsum paper board.

[0035] FIG. 1 shows a schematic of a method of producing a gypsum paper board. At reference sign 10, waste gypsum paper boards 10 are provided. The waste gypsum paper boards 10 are fed to a shredder 11, where the waste gypsum paper boards are shredded (e.g. into pieces of approximately 2020 cm). From the shredder 11, the broken parts of the waste gypsum paper boards are fed to a mill 12 wet grinding the broken parts. Water 13 for the wet grinding can be provided before the shredder 11, within the shredder 11, between the shredder 11 and/or the mill 12 or in the mill 12 as indicated by broken arrows. From the mill 12, a paper gypsum slurry containing water, paper particles (fibres) and gypsum particles (powder) is fed to a (main) mixer 14. Furthermore, stucco 15 and (optionally) further additive 16 (such as other gypsum varieties, such as calcium sulphate at certain and/or different states of hydration, and/or retarders and/or foaming agents and/or accelerators) are fed to the mixer 14. In the mixer 14 a gypsum slurry is mixed and fed onto a forming device 17 (such as forming table or forming band). There, paper layers 18 and 19 are added to the slurry. The slurry together with paper layers 18 and 19 settles on the forming device 17. Next, the settled layer can be cut into boards 21 of an appropriate shape by a corresponding cutting device (such as a saw) so that a (new) gypsum paper board 21 is produced.

[0036] A silo 20 may be (optionally) provided between the mill 12 and the mixer 14 for storing the slurry coming from the mill 12 and for feeding the stored slurry to the mixer 14.

Reference signs

[0037] 10 waste gypsum paper board [0038] 11 shredder [0039] 12 mill [0040] 13 water [0041] 14 mixer [0042] 15 stucco [0043] 16 other material [0044] 17 forming device [0045] 18 paper layer [0046] 19 paper layer [0047] 20 silo [0048] 21 (new) gypsum paper board