Samara
0
RU EN

High-Strength Gypsum Plaster Production Technology

  /  
09.12.2019
31

Gypsum stone is a sulfate rock of sedimentary (chemical) origin with a monomineral granular-crystalline structure, composed of the mineral of the same name – calcium sulfate dihydrate. The resulting substance can be white or light gray, depending on the accompanying impurities of clay, sand and organic matter. 

Gypsum binders produced from gypsum stone are air-setting substances obtained by heat treatment of raw materials with preliminary or post-calcining grinding to a powder state. Heat treatment can be low-temperature (120–180°C) and high-temperature (600–700°C).

High-strength gypsum  is a material obtained by processing crushed gypsum stone with saturated steam at a temperature of 123°C or by boiling in aqueous solutions of some salts (for example, calcium chloride) followed by drying and grinding. 

After such treatment, gypsum dihydrate, composed of small lamellar crystals, recrystallizes into coarse-grained hemihydrate gypsum of alpha modification with long needle-like or prismatic transparent hexagonal crystals.

The high-strength gypsum plaster is characterized by high water requirement (lower than that of the standard construction gypsum) and sufficient maximum compressive strength after 2 hours. With an increase in the content of dihydrate in natural raw materials and a corresponding decrease in impurities, the quality of gypsum plaster also increases. 

Production:

To obtain high-strength gypsum plaster of the first grade, the dihydrate content in the raw material should be at least 95%. High-strength gypsum plaster is a fast-setting (2-20 minutes) and fast-hardening (15-30 minutes) product.

Heat treatment of gypsum crushed stone for high-strength α-gypsum binder is carried out in vertical autoclave-steamers with external steam supply or in self-steamers where the steam is produced by evaporation of hygroscopic and partly combined water. These technological procedures are based on results of extensive and long-term studies by various specialists. 

Moreover, the interest in developing advanced methods for heat and steam treatment of the raw product is unfailing, because this procedure is essential for improving the quality of the finished product – an important construction material.

Location:

Samara, Russia
or choose another

Ask a Question

By clicking Submit button, I give consent to the storage and processing of my personal data.

Thank you! Your feedback has been successfully submitted.

Our manager will contact you shortly, thank you for waiting.

New opinion

By clicking "Send", I consent to the storage and processing of my personal data.

Thanks! Your review has been sent successfully.

Our manager will contact you shortly, please wait.

Make order

By clicking Submit button, I give consent to the storage and processing of my personal data.

Thank you! Your feedback has been successfully submitted.

Our manager will contact you shortly, thank you for waiting.

COMPLAINTS FORM

Select date in calendar
By clicking Submit button, I give consent to the storage and processing of my personal data.

Thank you! Your application form has been successfully submitted.

Our manager will contact you shortly, thank you for waiting.