Neelkanth Fitraids And Mineral Products

As you know, plaster results from the calcination of gypsum (CaSO4, 2 H2O), which partially dehydrates to produce a hemi-hydrate (CaSO4 , ½ H2O). The oldest traces of plaster renders are 9,000 years old, and were found in Anatolia and Syria.  We also know that 5,000 years ago, the Egyptians burnt the gypsum in open-air fires, then crushed it into powder, and finally mixed this powder with water to make jointing material for the blocks of their monuments, such as the magnificent Cheops Pyramid for example. The Greeks also used gypsum, in particular as window for their temples when it was of a transparent quality (selenite gypsum).

Throughout the centuries, expertise was gained in many parts of the World with gypsum calcination and the use of plaster (mostly as render for walls and ceilings and as jointing compound for walls). In the 1700's, Paris was already the "capital of plaster" since all the walls of wooden houses were covered with plaster, as a protection against fire. The King of France had enforced this rule after the big London fire literally destroyed this city in 1666. By the end of the 19 th century, plaster was used in the construction industry in a very massive way, in Paris and many other cities around Europe.

During the 20th century, plaster was found to be of great use outside of the construction industry. For example in the ceramic industries sanitary ware, vtableware, giftware, in dentistry, in metal casting, jewelry, in medical applications, in cosmetics, animal food, and many more applications. It looks like each decade brings new uses for this material.

First select the Gypsum  and preparation (cleaning, classifying) are key factors to produce the best plasters.

The chemical reaction is:

(CaSO4, 2 H2O) + heat  = (CaSO4, ½ H2O) + 1.5 H2O

Several processes are available to calcine gypsum into Plaster of Paris. We can distinguish two categories :

1st: Calcination under atmospheric pressure to produce Beta plaster

2nd: Calcination  under elevated pressure to produce Alpha plaster.

Controlling some critical calcination parameters is essential to master the growth of the plaster crystals. And the performance of the plaster depends a lot on its crystals' sizes and shapes. Therefore process know-how and control are key-expertise for plaster manufacturers.

Grinding plaster will determine the particle size distribution of the powder. Different applications call for different granulometric distributions, and Neelkanth  uses different types of grinding processes which enable to serve of markets.

Finally, the plasters will be mixed with additives and fillers, in order to adjust their rheological characteristics ,setting times, fluidity, their hardening kinetics, their permeability their mechanical strengths, their resistance to abrasion, etc

Neelkanth plaster know not only how  to formulate for all types of applications, but also which additives to choose in order to delay the ageing process of the plaster in bags, a distinctive competitive-edge.