Calcination is a heat treatment process where ores or other solid materials are heated below the melting point in the absence or a limited supply of air. This process is done to induce thermal decomposition, the removal of a volatile fraction, or phase transition.

Typically, calcination furnaces are heated to process temperatures of 800^oC to 1300^oC, depending on the application. Other calcination process parameters can include tight thermal profiles with strict tolerances.

Calcination furnaces can vary in their configuration, but typically they are either muffle, reverberatory, or shaft furnaces or kilns. When a sample is being calcinated it is often stirred to ensure uniformity in the final product.

Muffle furnaces are built so that the heat source doesn’t come into contact with the sample that is being calcinated, they are often constructed of iron, brickwork or fire-clay. In a reverberatory calcination furnace, the heat source comes in direct contact with the sample.

Shaft furnaces or kilns are either periodic or continuous. Periodic calcination furnaces are cooled before the sample is withdrawn, while the sample in a continuous calcination furnace is withdrawn without any cool-down. Continuous furnaces are a more popular choice due to the energy and time savings.

Calcination Furnace Applications

General applications of calcination furnaces include removing water from a sample, which is present as absorbed moisture; removing volatile constituents such as carbon dioxide or sulfur dioxide; or to oxidize part of or the entire substance.

The most common application of calcination furnaces is to produce cement. This is achieved by decomposing calcium carbonate into calcium oxide and carbon dioxide.

These furnaces are also used in the synthesis of zeolites to remove the ammoniumions, and in the devitrification of glass, materials to affect the phase transformations.

Calcination Furnaces from Thermcraft

Thermcraft manufacture and supply a large range of industrial furnaces that can be used for calcination. Our products range from standard designs that can be shipped quickly to solutions that can be customised to exact specifications.

We pride ourselves on our high levels of customer service and support, and our team is happy to provide any advice when selecting the right calcination furnace for your application.

If you’re looking to purchase a calcination furnace but aren’t sure on what specifications are suitable for your requirements, please contact us and a member of our team will be happy to help.