GEBR. PFEIFFER SE

Grinding and calcining of gypsum with Pfeiffer grinding plants

For the production of plaster products natural gypsum, synthetic gypsum or a mixture of both are calcined. Depending on the production process two different modifications of the hemihydrate CaSO4 x ½ H2O are obtained.

When gypsum is calcined in an atmosphere sat­urated with water vapour at an overpressure of several bars, a-hemihydrate is formed (Fig. 1). The outstanding feature of this plaster is a relatively regular crystal form. It is created due to the fact that the crystal water is able to escape from the intermediate lattice structure of the CaSO4 slowly and uniformly as escaping is greatly hampered by the counter-pressure built up by the water vapour.

Due to the relatively regular crystal structure and the large individual crystals of the a-hemihydrate, there are few contact surfaces for...

Related articles:

Issue 03/2009 Materials Science

Acceleration of the setting of hemihydrate plaster with calcium sulfate dihydrate

1 Introduction Calcium sulfate binders are required to have widely varying properties to meet technical and economic requirements. In particular, it has to be possible to vary the workability time and...

more
Issue 1-2/2020 GEBR. PFEIFFER SE

Gebr. Pfeiffer sells another gypsum calcining mill to Indonesia

Another customer could be convinced of the many advantages of Gebr. Pfeiffer’s vertical roller mills with integrated gypsum calcination: PT Siam-Indo Gypsum Industry has ordered an MPS 180 GC for its...

more
Issue 10/2014 PFEIFFER CONVENTION, KAISERSLAUTERN/GERMANY (08.–?09.05.2014)

2014 – Pfeiffer Convention celebrates 150 years anniversary

Patrick Heyd (General Manager Projects and Sales) opened the event with a warm welcome to the 200 guests from 35 countries and led the audience through the Pfeiffer Convention on 8–9 May 2014. The...

more
Issue 02/2013

Gypsum calcining mills for Brazil and Kazakhstan

Knauf Engineering GmbH ordered one Pfeiffer MPS 180 GC vertical roll mill each for its ­Bahia works in Brazil and its Kaptschagaj works in ­Kazakhstan. Both MPS mills are designed for the...

more
Issue 03/2014

Gypsum mill for Algeria

Grenzebach BSH from Bad Hersfeld/Germany has ordered a Gebr. Pfeiffer vertical roller mill of the type MPS 100 GC for a plant in Bou Saada/Algeria. The MPS mill is designed for the grinding and...

more