Method For Reducing Elemental Sulfur In Gypsum Products

Active Publication Date: 2017-05-04
CERTAINTEED GYPSUM INC
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  • Abstract
  • Description
  • Claims
  • Application Information

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Benefits of technology

[0014]The method of the present disclosure provides an advantage by

Problems solved by technology

A significant problem has arisen regarding certain drywall that was imported into the United States from the People's Republic of China.
Homeowners have reported that these emissions resulted in various househo

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  • Method For Reducing Elemental Sulfur In Gypsum Products
  • Method For Reducing Elemental Sulfur In Gypsum Products
  • Method For Reducing Elemental Sulfur In Gypsum Products

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DETAILED DESCRIPTION OF THE DRAWINGS

[0026]The present disclosure relates to methods for reducing levels of elemental sulfur within gypsum products such as wall board. Natural gypsum often includes increased levels of elemental sulfur. Such elemental sulfur can be corrosive and otherwise harmful at elevated levels. The disclosure contemplates reacting the elemental sulfur with copper to produce copper sulfide. This reaction has the benefit of reducing the levels of elemental or orthorhombic cyclooctasulfur (S8) present within the final gypsum product. The copper can be added at any of a variety of locations in the manufacturing process. For example, the copper may be added prior to any calcining of the gypsum, at the output of a calciner, prior to the mixer, or within the mixer. The various methods of the present disclosure are described hereinafter.

[0027]FIG. 1A illustrates an apparatus for calcining gypsum 20. Apparatus 20 includes a gypsum conveyor 22 for transporting a volume of ...

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Abstract

Disclosed are various methods for reducing levels of elemental sulfur within gypsum products such as wall board. Gypsum sometimes includes increased levels of elemental sulfur. Such sulfur can be corrosive and otherwise harmful at elevated levels. The disclosure contemplates reacting the elemental sulfur with copper to copper sulfide. This reaction has the benefit of reducing the levels of elemental sulfur present within the final gypsum product. The copper can be added at any of a variety of locations in the manufacturing process. This is a very efficient method for reducing elemental sulfur in the production of gypsum products.

Description

TECHNICAL FIELD[0001]This disclosure relates to a method for reducing elemental sulfur in gypsum products. More specifically, the disclosure relates to reducing elemental sulfur in gypsum via the addition of copper.BACKGROUND OF THE INVENTION[0002]Gypsum board is one of the most widely used and versatile building materials in the world. The basic construction for gypsum building boards has remained unchanged for quite some time. This construction includes a core of calcium sulfate dihydrate (CaSO4 2H2O) that is sandwiched between opposing paper sheets.[0003]The gypsum can be either artificially produced or mined. Naturally occurring gypsum must be ground and crushed in a mill prior to use. Thereafter the ground gypsum is heated in a kettle whereby it is calcined to produce calcium sulfate hemihydrate (CaSO4½H2O) (or stucco) in accordance with the following equation:CaSO42H2O+Heat→CaSO4½H2O+1½H2O[0004]The calcined gypsum is thereafter mixed with water to form a stucco slurry. Other a...

Claims

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Application Information

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IPC IPC(8): C01F11/46
CPCC01F11/466C01F11/468C01G1/12C01G3/12C04B28/145C04B11/007C01P2006/80C04B2111/0062C04B2111/10C04B14/42C04B22/14C04B24/08C04B24/10C04B24/383C04B38/10C04B2103/0016C04B2103/20
InventorCOLLEGE, JOHN W.LEE, SANG-HOHILTON, CHRISKIANG, YU-ZHILAI, CHOUNG-HOUNGGLAVIN, GEORGEILYASHENKO, HELEN
OwnerCERTAINTEED GYPSUM INC