Method of processing plasterboards

Patent metadata

Field	Value
Publication number	US-2021002172-A1
Application number	US-201916965869-A
Country	US
Kind code	A1
Filing date	Jan 29, 2019
Priority date	Jan 30, 2018
Publication date	Jan 7, 2021
Grant date	—

Abstract

A method of processing plasterboards or plasterboard for recover a calcium sulphate source for producing a hydraulic binder, includes comminuting plasterboards or a gypsum fraction thereof so as to obtain plasterboard particles and, thereafter, subjecting the plasterboard particles to a heat treatment at an elevated temperature so as to volatilize and/or decompose organic components present in the plasterboard particles.

First claim

1 . A method of processing plasterboards for recovering a calcium sulphate source for producing a hydraulic binder, comprising the steps of
a) comminuting plasterboards or a gypsum fraction thereof so as to obtain plasterboard particles, b) subjecting the plasterboard particles to a heat treatment at an elevated temperature so as to volatilize and/or decompose organic components present in the plasterboard particles, wherein the heat treatment is carried out for a time period of less than 10 min.

2 . The method according to claim 1 , wherein the heat treatment comprises subjecting the plasterboard particles to a temperature in the range of 300° C. 550° C.

3 . The method according to claim 1 , wherein the heat treatment comprises subjecting the plasterboard particles or the gypsum fraction thereof to a temperature of 300° C.-390° C.

4 . The method according to claim 1 , wherein the heat treatment is carried out for a time period of 3-5 min.

5 . (canceled)

6 . The method according to claim 1 , wherein the heat treatment is carried out for a time period of ≥4 min.

7 . The method according to claim 1 , wherein, before or after step a), a front and a back layer fraction is separated from a gypsum fraction of the plasterboard material.

8 . The method according to claim 1 , wherein step b) is carried out in an atmosphere that has an O 2 -content of greater than 10 vol. %.

9 . A method comprising utilizing a calcium sulphate source obtained by a method according to claim 1 as a component in the production of a hydraulic binder.

10 . The method according to claim 9 , wherein the calcium sulphate source is mixed with clinker and the resulting mixture is ground in order to obtain ordinary Portland cement.

11 . The method according to claim 1 , wherein the time period is from 1 to 9 min.

12 . The method according to claim 11 , wherein the time period is from 2 to 6 min.

13 . The method according to claim 12 , wherein the time period is from 4 to 6 min.

14 . The method according to claim 2 , wherein the temperature is in the range of 350° C.-550° C.

15 . The method according to claim 14 , wherein the temperature is in the range of 400° C.-500° C.

16 . The method according to claim 3 , wherein the temperature is of 310° C.-350° C.

17 . The method according to claim 6 , wherein the time period is from 4 to 9 min.

18 . The method according to claim 17 , wherein the time period is from 5 to 7 min.

19 . The method according to claim 7 , wherein the front and the back layer fraction is a paper and/or cardboard fraction.

20 . The method according to claim 8 , wherein the atmosphere has an 02-content of greater than 15 vol. %.

Assignees

• Holcim Technology Ltd

Inventors

• Kruspan Peter
• Stemmler Konrad
• Dagge Ludger
• Langanke Melanie

Classifications

• B09B3/40

  involving thermal treatment, e.g. evaporation (processes using mineral binders involving a melting or softening step B09B3/29; involving radiation B09B3/50) · CPC title

• C04B28/142

  containing synthetic or waste calcium sulfate cements · CPC title

• C04B11/005 Primary

  Preparing or treating the raw materials · CPC title

• C04B11/262

  waste gypsum other than phosphogypsum · CPC title

• C04B11/02

  Methods and apparatus for} dehydrating gypsum {(for other purposes than cement manufacture C01F11/466) · CPC title