Manganese and Rhenium

Abstract

Manganese is chemically reactive metal with physical characteristics varying from hard and brittle to soft and flexible. Main use of manganese is in steel production. The major non-metallurgical use of manganese is as manganese dioxide for producing dry-cell batteries. Organic manganese compounds include methylcyclopentadienyl manganese tricarbonyl used as an additive to gasoline, ethylene-bis-dithiocarbamate pesticides maneb and mancozeb, and an image enhancer manganese dipyridoxyl diphosphate. Main health hazard of manganese is neurotoxicity. Recent epidemiological studies show that subtle neurobehavioral effects, including fine deficits in motor performance and in attention, can be seen at exposure levels of ≥0.02–0.03 mg Mn/m3 as respirable dust. Rhenium is characterized by a very high melting temperature and density. Very few data exist on the toxicity of rhenium. Keywords: manganism; neurotoxicity; welding; ferroalloy production; manganese dioxide; methylcyclopentadienyl manganese tricarbonyl ; perrhenates