Advanced Calcination & Drying Systems for Gypsum Production Plants
In industrial gypsum and construction chemicals production, the most critical stage determining the quality, strength, and workability of the final product is the calcination (calcining and drying) process. Run-of-mine gypsum rock (calcium sulfate dihydrate), extracted directly from the quarry or supplied from crushing and screening plants in 0–10 mm particle size, naturally contains 18–20% chemically combined (crystal) water.
The calcination process is based on the controlled thermal removal of this chemically combined water, reducing the crystal water content to approximately 4–6%. This thermodynamic transformation produces beta hemihydrate gypsum (base plaster)—the high-performance binder that serves as the primary raw material for the construction industry.
At IPS Makina, we design and deliver turnkey calcination systems engineered to achieve maximum energy efficiency, zero process deviation, and complete product homogeneity, selecting the most suitable kiln technology according to your plant layout, production capacity, and raw material characteristics. To ensure optimum calcination quality, we offer two internationally proven industrial kiln technologies: the Gypsum Rotary Kiln and the Vertical Kiln.
1. Gypsum Rotary Kiln
The Gypsum Rotary Kiln is the preferred technology for high-capacity, continuous production lines operating under heavy industrial conditions. Rotary kilns consist of large steel cylinders installed at a slight incline and rotating slowly around their longitudinal axis.
This system provides the highest flexibility and tolerance for the simultaneous calcination of raw materials with a wide particle size distribution, typically 0–10 mm.
Operating Principle & Technical Features
Thermal Flow & Combustion Chamber
The required process heat is generated by proportionally controlled burners installed in the combustion chamber at the kiln inlet or outlet. Depending on process requirements, the system can be designed for either direct-fired or indirect-fired operation.
Special Internal Design (Lifter & Star System)
The internal surface of the kiln is equipped with lifting flights and specially designed star systems engineered by IPS Makina. As the kiln rotates, the material is lifted and cascades through the hot gas stream, creating a material curtain that maximizes the contact area between each gypsum particle and the process gases, resulting in highly efficient heat transfer.
Mechanical Drive System (Tyres, Support Rollers & Gearing)
To rotate large quantities of material safely and continuously, the kiln shell is supported by heavy-duty riding rings (tyres) and support rollers. These drive components are manufactured from specially heat-treated alloy steels to provide maximum resistance against wear and metal fatigue.
Temperature & Moisture Automation
Flue gas temperature, kiln rotational speed, and feed rate are continuously synchronized through the PLC control system. This ensures that the gypsum is neither over-calcined (burnt gypsum/anhydrite formation) nor under-calcined, maintaining consistent product quality.
Advantages of the Gypsum Rotary Kiln
2. Vertical Kiln
The Vertical Kiln is an advanced engineering solution developed for modern gypsum production plants, offering a compact design, superior thermal efficiency, and outstanding performance in the calcination of pre-ground, micronized gypsum powders.
Vertical kilns operate using either the counter-current heat exchange principle, where material flows downward by gravity while hot gases move upward, or the fluidized bed principle.
Operating Principle & Technical Features
Counter-Current Thermodynamic Effect
Gypsum particles fed from the top encounter a high-pressure upward flow of hot air. This counter-current contact maximizes the heat transfer coefficient, achieving highly efficient calcination within a very short residence time.
Precise Temperature Control
Since the heat zone is distributed uniformly along the vertical axis of the kiln, the material is exposed to a precisely controlled temperature profile. As a result, the risk of over-burning is virtually eliminated.
Compact Plant Footprint
Thanks to its vertical configuration, the kiln occupies minimal ground space, making it an ideal solution for projects with limited land availability or for integration into existing production facilities.
Low Radiant Heat Loss
The external surface area of a vertical kiln is considerably smaller than that of a rotary kiln, significantly reducing radiant heat losses and contributing directly to lower fuel consumption.
Advantages of the Vertical Kiln
Heavy-Duty Mechanical Infrastructure (Tyres, Support Rollers & Gearing)
Calcination kilns are massive heavy-duty machines designed for the continuous processing of large quantities of material. The mechanical drive system plays a critical role in ensuring smooth kiln rotation and maintaining structural integrity throughout the equipment's service life.
Riding rings (tyres), support rollers, and drive gears are dimensioned according to the calculated operating load of the kiln and manufactured from heavy-duty cast steel in accordance with industrial standards. Following casting, these critical components are precision-machined and subjected to specialized heat treatment processes to achieve the required hardness and mechanical strength.
This manufacturing process minimizes mechanical wear, extends maintenance intervals, and ensures reliable, uninterrupted, and long-term operation.