Sarah Everts explains how researchers seek ways to recycle the alumina refining waste that caused catastrophe in Hungary. Ripe for reuse Researchers are looking for alternative uses for the red mud that devastated the Hungarian countryside. A staggering 70 million tons of red mud is produced worldwide every year to extract alumina from bauxite in a process that's been used for more than 100 years. Researchers have long tried to find ways to recycle or reuse the waste - well before the disaster in Hungary. Red mud gets its rusty color from iron oxide, which can be as much as 50% of the material. One proposed use for red mud is as an ingredient in bricks and roof tiles. The challenge is to ensure that toxic ingredients are at safe levels. For example, George N. Angelopoulos, a chemical engineer at the University of Patras, in Greece, found that red mud from Greek bauxite mines has to be limited to 30% of the total content of bricks to keep chromium at safe levels.