Frequently Asked Questions
What is “Red Mud”?
“Red Mud” is called a by-product/waste that derives from the alumina producing industries. It is called “Red” because usually has a red colour (due to iron oxides) and “Mud” because it is a slurry. It is often also named “Bauxite Residue” whereas proprietary names of processed Red Mud can be found, such as “Bauxsol”™ (Virotec), “Cajunite”™ (Kaiser Aluminium), “Bauxaline”® (Aluminium Pechiney), “Ferroalumina” (Aluminium de Grece) etc.
Is it toxic?
In general, the potential for danger to human health and the environment is low and the material is classified as non toxic and non dangerous. However, toxicity should be related to the disposal method practised and there is always a possibility of (heavy) metals leaching if the appropriate actions are not followed.
Is it radioactive?
Red Mud derives from bauxite and has typically twice the concentration of natural radionuclides found in parent mineral. Therefore, Red Mud, can be regarded as a Technologically Enhanced Naturally Occurring Radioactive Material (TENORM). In one reference [W. Kurdowski, F. Sorrentino, in “Waste Materials Used in Concrete Manufacturing”, pp. 290-308, Edited by Satish Chandra, William Andrew Publishing/Noyes, 1997], it is reported that Jamaican bauxite and the corresponding Jamaican RMs contain levels of U238 and Th232 significantly greater than those found in most other local soils. The same source refers that the mean specific activity of Ra226, Th232 and K40 in RM is 477, 705, and 153Bq/Kg. In all cases, these values should be seen only as indicative since it is obvious that the final values would depend on the bauxite used. For more references on the subject please visit the Bibliography.
How we dispose Red Mud now?
There are a number of ways. Conventional disposal methods involve the construction of clay-lined dams or dykes, into which Red Mud is simply pumped and allowed to dry naturally. As an alternative, dry disposal, involving enhanced dewatering and evaporative drying is also used, whereas in a few occasions sea disposal takes place. Please see also the page on Disposal.
What are the most promising uses for Red Mud?
By regarding as promising a use that can absorb substantial quantities and promote added value to Red Mud, we believe that the metallurgical, cement and traditional ceramic industries are highly likely to offer a solution.
Why so far don’t we use Red Mud in industrial process?
The main reason is that the proposed processes are usually not economically viable, whereas in many cases technological limitations further limit such a potential. In view of the tendency for reformation to more strict environmental policies, it is more likely that industrial processes will be implemented to absorb Red Mud.
What is the purpose of this site?
The purpose of the site is to provide reliable information on Red Mud and in addition:
a) to be used as a reference point for discussions, presentation of scientific findings and ideas for technological solutions
b) to assist in the development of a network of excellence among professionals that would promote and influence the implementation of “best applicable techniques” for Red Mud recycling
c) to positively influence the usual industrial practices on the disposal of Red Mud by demonstrating through scientific research that alternative, more environmental friendly ways are feasible.
Who is supporting this site?
We are a small group of researches (two professors and two phD students) however we hope that this soon is going to change since we need greater human resources. Everyone is welcomed to contribute! Please contact with us in case you are interested.
How can I join?
If you are an individual you can simply contact us and we will keep you informed about all the new material that is being added to the site. If you are involved in the Red Mud problem, please advise the Join Us section for further details on how to participate in the “Red Mud Project”