Views: 52 Author: Site Editor Publish Time: 2017-06-06 Origin: SEPPE
Brown Fused Alumina, usually abbreviated “BFA”, is a raw material used in refractory and abrasives production. Due to its wide range of uses, worldwide demand for BFA is substantial. Many suppliers and members of the refractory industry are becoming increasing curious, how exactly is Brown Fused Alumina produced? And what are its characteristics? The Refractory Team at OKorder would like to take this opportunity to answer these questions!
First, how is Brown Fused Alumina produced? Brown Fused Alumina (BFA) is made from Calcined Aluminate Bauxite, anthracite and scrap iron in an electrical furnace. The content of Calcined Bauxite should coincide with a minimum Al₂O₃ content of 80%, a max of 3% SiO₂, and a max of Fe₂O₃ and TiO₂ of 6%; as for anthracite coal, the fixed carbon should be over 80%; scrap iron Fe content must over 80%. The most important variable in the production process is the electrical furnace’s temperature when melting the raw materials using a graphite electrode – the temperature must be over 1750°C. After completing the melting process, the molten material is allowed to cool naturally. Once cooled, a crushing machine is used to break up the bigger pieces. According to different client requirements, plants may crush the material in a Barmaq or lemon mill to produce smaller sizes. Once crushed to the appropriate size, the cargo can be directly packed after processing. Typical requirements are for sizes 0–1mm, 1–3mm and 3–5mm, packed in a jumbo bag.
The production of Brown Fused Alumina (BFA) seems easy, but to produce quality product, plants need to be very experienced in controlling raw material quality, temperature, electrode shift speed, and many more variables. There are many lower grade BFAs (94% or 94.5% Al₂O₃) and are all the result of raw material and temperature issues.
Here are a few of the significant characteristics of Brown Fused Alumina (BFA):
High bulk density and hardness (normally above 3.5g/cm³)
For tilting furnace produced brown fused alumina (BFA), Al₂O₃ above 95%
Hard with some flexibility
Brown Fused Alumina (BFA), on the basis of its Alumina content and bulk density and due to its characteristics, is the choice of many refractory plants that produce shaped and monolithic materials, abrasive producers, and many more buyers all over the world.