Rotary Calciner
Rotary calciners (sometimes referred to as rotary kilns) are used for a variety of material processing applications. These high temperature machines process materials into a desired form by changing the state or composition of a material, or removing moisture. Unlike directly fired calciners, indirect rotary calciners are heated from the outside of an enclosed chamber. This gives them the ability to process materials that are fine or dusty, susceptible to contamination or combustion, sensitive to oxidation, or thermally sensitive. With this advantage, indirect rotary calciners have the ability to process a wide variety of materials.
The rotary calcination process begins with raw materials that are fed into one end of the calciner. These materials are gradually heated along the chamber body of the calciner, often in various temperature zones. As the material is fed into the calciner, a rotating cylinder gently pushes the material along the chamber. This rotation promotes even material distribution and processing. Rotation speed and temperature are tightly controlled according to the desired process or material application. During this process, chemical reactions may take place, the state of the material may change, or moisture may be removed, depending on the specific application that’s required. Because heat is applied from outside the chamber, material integrity is preserved throughout the process. After completing the heating process, the material often goes through a cooling phase within the chamber, and is then deposited at the opposite end of the calciner in its finished form.
Rotary calciners are occasionally used in conjunction with a spray dryer to process materials that have already been spray dried into to powders. This additional processing can accomplish desired material changes for advanced manufacturing applications.
Rotary Calciner Applications
Calcination
Calcination, often referred to as thermal processing, involves heating a specified material to a specific temperature in order to cause thermal decomposition. For example, in the case of limestone, calcination is used to drive off carbon dioxide.
Thermal Desorption
Thermal desorption refers to the process of utilizing heat to remove or vaporize a specific component from a material. Indirect rotary calciners are especially useful for this application, because the flame does not come into direct contact with the material.
Drying
Rotary calciners can also be used to dry bulk materials, because of their ability to tightly control air temperature and material integrity. In these applications, the machines are sometimes referred to as rotary kiln dryers.
Commonly Calcined Materials
- Advanced Ceramics
- Alumina
- Anatase/Rutile
- Bauxite
- Calcium Carbonate
- Catalysts
- Dolomite
- Glass Materials
- Gypsum
- Hydrotalcite
- Kaolin
- Limestone
- Phosphate Ore
- Silica
- Specialty Chemicals
- Zeolites
- Zinc Carbonate
Toll Processing Services
Elan Technology offers toll processing services for a variety of raw materials and desired applications. Our indirect rotary calciner allows for precise material processing, with exact temperature and speed controls. We have the ability to process powders or pellets, and have implemented a system for automated unloading and loading of bulk bags or drums. These benefits offer clear advantages for your material processing needs.
Our contract rotary calciner services offer a cost-efficient option for your material processing requirements. In addition, we also offer toll spray drying services for our customers, offering further cost savings and precision material handling. Contact us today to learn more about the services we offer.
Technical Specifications
- Heyl & Patterson rotary calciner
- Indirect gas fired rotary calciner via 12 burners and 3 zones
- Three individually controlled heat zones
- Wireless bed temperature monitoring
- Maximum Temperature 1035°C
- Cooling zone to reduce material temperature to 100°C or below
- Calciner tube diameter: 4 feet
- Calciner tube heated length: 30 feet
Full-Service Calciner Solutions
Contract Drying & Rotary Calciner Services
Elan Technology offers full-service calciner services with our onsite rotary calciner. A variety of advanced manufacturing applications require unique material changes, and our calcination services utilize highly-effective thermal processing treatments to achieve your desired outcome. Additionally, our on-site spray drying technology transforms a slurry — a mixture of liquids and solids — into free flowing dust-free powders.
Because Elan Technology offers both spray drying and calcining services, we can offer highly cost-effective solutions for our customers.
Under our contract services, materials are treated in order to promote optimal utility in various industrial applications. For example, alumina is commonly calcined to be employed in many refractory materials, and calcined dolomite powder is used in plastic compounds, paints, and detergents.
Contact us today to learn more about our full-service calciner solutions or contract spray drying services.
Calcining Services Frequently Asked Questions
What is calcining?
Calcining is a thermal treatment process used to induce a chemical change in a material by heating it to a high temperature. This process typically removes volatile components, drives off moisture, and/or induces a phase transformation. It is commonly used in the production of materials such as cement, lime, and ceramics.
What are the main applications of calcining?
Calcining is used across various industries, including:
- Cement Production: To convert limestone (calcium carbonate) into lime (calcium oxide).
- Metals and Minerals: To process ores and produce metal oxides and other compounds.
- Ceramics and Glass: To create materials with desired properties.
What types of materials can be calcined?
Common materials that are calcined include:
- Limestone
- Clay
- Bauxite
- Catalysts
- Chemical Precursors
How does calcining differ from other thermal processes like roasting or sintering?
- Roasting: Typically involves oxidation or reduction of ores at lower temperatures compared to calcining.
- Sintering: A process where particles are heated below their melting point to bond together, often used for ceramics and metals.
- Calcining: Primarily focuses on inducing chemical changes, such as decarbonization or phase transformation, through high-temperature treatment.
What are the key benefits of using calcining?
- Purification: Removes impurities and volatile components from raw materials.
- Transformation: Converts materials into a more chemically stable or useful form.
- Enhanced Properties: Improves material properties such as hardness, reactivity, or stability.
What temperature range is typically used for calcining?
The temperature range for calcining varies depending on the material. The maximum temperature for our calciner is 1000°C. Specific temperatures are tailored to the requirements of the material and desired outcome.
How do I know if calcining is the right process for my material?
To determine if calcining is suitable, consider:
- Material Composition: Does it require thermal treatment to achieve desired properties?
- Desired Outcome: Are you aiming for phase transformation, removal of volatile components, or purification?
- Processing Requirements: Can your material withstand high temperatures and the calcining environment?
What is the typical lead time for calcining projects?
Lead times vary based on the complexity and scale of the project. Generally, it ranges from a few weeks to several months. Please provide details about your material and requirements for a more accurate estimate.
Can you handle both small-scale and large-scale calcining projects?
Our production calciner has a diameter of 4’ and a heated section 30’ long. However, we can provide some development support for small samples in our laboratory.
What quality control measures are in place during calcining?
We implement comprehensive quality control measures, including:
- Monitoring: Continuous monitoring of temperature, pressure, and other process parameters.
- Testing: Regular sampling and analysis of material to ensure desired properties. Quality control monitoring can vary based on the the customer’s specifications.
How do I get a quote for calcining services?
To receive a quote, please contact us.
What information should I include in my initial inquiry?
- Material form (i.e. powder, extrudates, etc.) and median particle size
- Material bulk density
- Mass loss across calcination
- Desire temperature, and residence time
- Off gas release levels of NOx and VOC’s, if any
- Material angle of repose