The present invention relates to an inorganic, halogen-free flameproofing agent produced from modified, carbonized red mud (MKRS-HT) having a mineral composition of 10 to 50 weight percent of iron compounds, 12 to 35 weight percent of aluminum compounds, 5 to 17 weight percent of silicon compounds, 2 to 10 weight percent of titanium dioxide, 0.5 to 6 weight percent of calcium compounds and optionally unavoidable impurities, the weight ratio of Fe (II) carbonate to the oxides of iron being at least 1. The flame proofing agent according to the invention can be used as a flame retardant in the high-temperature range. The invention further relates to an inorganic, halogen-free flameproofing agent produced from modified, carbonized and rehydrated red mud, which can be used as a flame retardant both in the low-temperature range as well as in the high-temperature range, and to methods for producing same and the use thereof as flame retardants. The invention further relates to a flameproofed material system and methods for producing same. The compound according to the invention is suitable for applications such as drilling mud weighting, radioactive and electromagnetic shielding and as planting soil additive.