Rotary Kiln Calcination Ball Method
Rotary kiln calcination is a process used to heat raw materials such as ores and other inorganic substances to very high temperatures in order to create particles of a desired size, shape, and chemical composition. The process involves heating a rotary drum, known as a kiln, and rotating it at a constant rate. Heat is generated from burning materials such as coal, natural gas, or oil, or from electric elements. The rotating kiln helps with heat transfer, and the kiln is heated to temperatures between 500°C and 1500°C, depending on the materials heated.
The most common products created using the rotary kiln calcination process are cement, titanium dioxide, aluminum hydroxide, phosphates, and aluminum oxide. The rotary kiln calcination process can also be used to create particles of graphite, silicon carbide, and nitride alloys, among many other types of materials.
The way in which the material is ground in the rotary kiln calcination process is known as the ball-on-ball method. In this process, a measured amount of the material is ground into balls that are then placed in a rotating kiln. Heat is slowly conducted through the walls of the kiln and into the material itself. The ball-on-ball method uses the a high degree of heat exchange between the walls of the kiln and the balls themselves, meaning that the materials reach an even higher temperature than those reached in direct-contact calcination processes.
This calcination process is advantageous for materials due to the continual supply of fresh oxygenated air to the reaction. When the material is heated, it can be oxidized, reducing the chance of reduction. The rotary kilns atmosphere can also be carefully controlled, including the use of oxygen or other gases to further enhance the reaction.
The ball-on-ball method used by the rotary kiln ensures not just a thorough heat transfer to the material in question, but also a homogenous heat distribution throughout the body of the kiln itself. The temperature profile is different in the case of vertical kilns, as the gravity field influences the temperature of the mixture differently than in horizontal kilns.
Rotary kilns are most oftenly used to create chemical compounds and other solid materials due to their accuracy, efficiency, and certain advantages offered by the ball-on-ball method. This calcination process is highly durable, reliable, and in general requires very low maintenance. Materials created through the process of rotary kiln calcination can offer a variety of advantages, including increased resistance to corrosion, higher temperature materials with enhanced structural performance, and improved strength and durability of metallurgical products. The process of rotary kiln calcination is most typically used for refractory materials, minerals, and inorganic compounds.
