profile=""> gypsum uses for aac blocks
Srinivas: +91 9966871942
Chaitanya: +91 9032444837
Siva: +91 8712383363

What is the nature of Gypsum?

Gypsum contains calcium, sulfur bound to oxygen and water. In chemical terms it is known as ‘calcium sulfate dehydrate’. It is rich in minerals that take several forms, including alabaster, which is a material used in decoration and construction. In ancient Egypt, it was widely used in artistic constructions. A good example is the White Sands National Monument in New Mexico. It is the largest gypsum dune field in the world.


It is helpful to humans, animals, plant life and the ecology as it is not toxic in nature. In North America, the majority of gypsum produced is used to manufacture gypsum board, including building plasters. It is used in several other ways.


Natural and FGD Gypsum

There are two types of Gypsum. Natural and FGD. In, sedimentary rock formations, natural gypsum is found in more than 85 countries across the world. In US, Canada and Mexico large reserves of high-quality gypsum exists.

Formation of Natural Gypsum


Approximately, 21 pounds or 10 quarts of chemically combined water in 100 pounds of gypsum rock. It is mined, quarried, crushed by grinding it into fine powder. This process is called calcining; where the powder is heated to 350 degrees F, approximately. This drives off ¾ of the chemically combined water. The calcined product or hemihydrate, becomes the base for gypsum plaster, gypsum board, including several products from gypsum.


The manufacturing of gypsum board from Flue-Gas Desulfurization (FGD) is in use for more than 30 years. It can also be manufactured from byproducts of de-sulfurization of flue gas from the stacks of fossil-fueled power plants. The emissions from it are captured from smoke stacks, which can be purified into a hard substance and gypsum is manufactured. In US more than 50 per cent FGD gypsum is used. Incidentally, natural and FGD gypsum have the same chemical composition. They are made of calcium sulfate dihydrate (CaSO4·2H2O). FGD gypsum production and sales allows the power producers to capture ‘waste’ for reuse instead of merely storing it.


Synthetic Gypsum


Environmental pollution is reduced in the production of this extremely pure type of gypsum. In the year 2010, in US gypsum industry diverted 8 million approximately short tons of FGD gypsum. This was used for manufacturing of boards. If not it would have resulted in it being sent fill local lands.

This increase in the use of FGD gypsum has aided the growth of new plants near new building construction sites. There close proximity has helped in maintaining low pollution levels in the surrounding areas and save energy. Presently, in Northern parts of US, a major percentage of gypsum products are manufactured and dsitributed near installation sites.


Both the Environmental Protection Agency and the US Green Building Council use FGD gypsum board in their office buildings. It is only due to its ecological benefits.


Synthetic gypsum includes flue-gas desulfurization (FGD) gypsum, fluorogypsum, citrogypsum, and titanogypsum. It is suitable for use in wallboard constructions. A byproduct from manufacturing titanium dioxide is Titanogypsum.


Some types of FGD gypsum are generally considered unsuitable for use in gypsum board due to potential environmental hazards; for example, phosphogypsum may contain radon and radio nuclides. Synthetic gypsum with potentially harmful materials is not used to manufacture gypsum board. Members of the Gypsum Association do not use phosphogypsum to manufacture any gypsum-based product.


The gypsum industry contributes to a cleaner environment, most importantly in two ways. This done by using synthetic gypsum in its manufacturing process in order to keep the air clean. The natural and the synthetic gypsum used in gypsum board are considered to be safe and free from toxic nature.


There are certain impurities that are there in natural as well as synthetic gypsum. Generally, they are generally harmless and inert. Natural gypsum in its typical form contains clay, anhydrite or limestone. Synthetic gypsum contains fly ash. Wallboards can be manufactured in modern plants by not making use of gypsum in natural form. This is despite the fact that in most of the plants synthetic gypsum is incorporated to produce with a mixture of synthetic and natural ore.


 Making of AAC Blocks

frequently asked questions on AAC Blocks

Advantages of ClC Blocks

frequently Asked questions on CLC Blocks

ClC Blocks Making Machinery

Latest Blog Posts


Siva & Srinivas
# 53-41-4, Near Sivalayam,
Maddilapalem, Visakhapatnam,
A.P. South India.


CLC Brick Qualities

Light in Weight
High Thermal Insulation
Flexible in Size
High Fire Protection
High Sound Insulation
Lower Water Absorption
Universal Acceptability