High-Temperature Processing of Powders and Bulk Solids
Process powders and bulk solids at elevated temperatures using controlled drying, mixing and reaction technologies. High-temperature powder processing is applied when conventional unit operations cannot achieve the required material transformation, moisture reduction or product performance. Selecting the appropriate process depends on thermal stability, residence time and heat transfer behaviour. Hosokawa Micron develops powder processing equipment and integrated systems designed for reliable operation up to 325°C, ensuring controlled processing at industrial scale.
When to apply high-temperature processing
High-temperature processing is typically introduced when material transformations cannot be achieved under conventional conditions. This includes activation of chemical reactions, removal of bound moisture or residual solvents, and modification of particle structure or surface properties. In these cases, increasing process temperature changes reaction kinetics and material behaviour, enabling new product characteristics that are not achievable at lower temperatures. At the same time, elevated temperatures can reduce process time and improve overall efficiency, provided that thermal exposure is carefully controlled.
Process considerations at elevated temperatures
Operating at high temperatures introduces additional engineering constraints that must be addressed at system level. At elevated temperatures, material behaviour may change significantly, affecting particle morphology, porosity and bulk behaviour. Powders can become sticky, reactive or prone to degradation, requiring controlled residence time and uniform heat distribution.
From a mechanical perspective, critical components such as seals, bearings and drive systems must be protected from thermal exposure. High-temperature processing systems are therefore designed to separate heat-sensitive components from the process zone, while using temperature-resistant materials and sealing solutions.
Process safety is also a key consideration, particularly when handling organic or carbon-based materials where oxidation or thermal degradation must be prevented.
Combining unit operations in a single process
Where required, combining multiple unit operations within a single system can improve process control and reduce product handling. Integrated processing allows operations such as mixing, reaction, drying and agglomeration to take place in a controlled environment, minimising contamination risk and reducing intermediate transfer steps. This approach is particularly relevant for contained processing, where product integrity and operator safety are critical.
High-temperature drying and reaction technologies
Conical Paddle Dryer
The Conical Paddle Dryer by Hosokawa Micron is designed for processes requiring controlled heat input under vacuum, atmospheric or pressurised conditions. This includes drying of powders, filter cakes and pastes, solid-gas reactions, crystallisation processes and thermal treatment. The combination of intensive mixing and controlled heat transfer allows uniform temperature distribution, which is essential for consistent product quality at elevated temperatures.
DMR flash dryer
The DMR flash dryer by Hosokawa Micron combines drying, de-agglomeration and classifying in a single continuous process. Due to very short residence times, materials can be exposed to relatively high temperatures while limiting thermal degradation. This makes flash drying suitable for temperature-sensitive products that still require intensive drying. The system can process feed materials ranging from slurries and pastes to filter cakes and wet powders, while producing a defined particle size distribution.
Application examples
Polymer processing
In polymer processing, high-temperature treatment is often applied after synthesis to remove residual monomers and moisture, followed by thermal conditioning to modify material properties. These steps can be combined within a single system, allowing precise control of temperature profiles over time. Preventing oxygen ingress is critical in these processes to avoid oxidation or degradation. The ability to apply different temperature levels during the process enables controlled modification of polymer characteristics, depending on the final application.
Catalyst production
High-temperature processing is also used in catalyst production, particularly during carrier preparation and activation. Flash drying can be applied to convert mechanically dewatered filter cakes or slurries into dry, free-flowing powders in an energy-efficient manner. Compared to spray drying, this approach reduces the need for additional water and lowers evaporation demand. Subsequent processing steps, such as impregnation of active components, can be carried out using mixing and drying technologies such as the Nauta® conical screw mixer by Hosokawa Micron, ensuring homogeneous distribution prior to thermal treatment.
From process development to industrial production
High-temperature processing requires testing under controlled conditions due to the interaction between material behaviour and thermal exposure. Hosokawa Micron supports process development through laboratory and pilot-scale testing in its Test Centre in the Netherlands, enabling the definition of process parameters before scale-up. This ensures reliable translation from test results to industrial production systems.
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Discuss Your Process
Our engineers support the selection and optimisation of high-temperature powder processing systems, from testing to industrial-scale production.
Sustainable Process Technologies
Hosokawa Micron develops powder processing systems with a focus on energy efficiency, process optimisation and long-term operational performance. As an ISO 14001 certified company with an EcoVadis Silver Medal, we support more sustainable powder and bulk solids processing.
