Manganese (Mn) and its toxicity

Manganese (Mn) and its toxicity

Introduction

Manganese is a chemical element that has the symbol Mn and atomic number 25. The term "manganese" could come from several sources:

It would come from the Latin "magnesi nigri" magnesia black MnO2. To avoid confusion with the magnesium, the original name was changed manganesium.

The name derives from the magnetic properties of pyrolusite, a mineral that was already known in antiquity.

Manganese is a transition metal gray that resembles iron. It is a hard and brittle metal, it melts easily, but it is easily oxidized. Manganese is ferromagnetic only after special treatment. Manganese compounds where it is in a state +7 are powerful oxidizing agents (e.g. potassium permanganate KMnO4, color dark purple well known or heptoxide dimanganese Mn2O7, the oxidizing properties spectacular).

Physical properties

Manganese is a silver white metal

Its density is 7.2g/cm3

It is hard and brittle

In air, manganese coated colorful spots of the oxide film, which protects it from further oxidation

With iron, manganese forms alloys with any ratio of components (ferro)

It can easily be dissolved in water

The solid manganese does not evaporate except those smaller particles of manganese which suspend in air

Chemical properties

Manganese is quite active when heated vigorously with non-metals such as sulfur, carbon, phosphorus and others. At room temperature the manganese in the air does not change: it is very slow to react with water. In acid (hydrochloric acid, dilute sulfuric), it easily dissolves to form salts of divalent manganese. When heated in a vacuum, Manganese is volatile even alloy.

Manganese forms alloys with most of the metals dissolved in some of its versions and stabilize them. Compound Mn (+2) are reducing agents. Compound Mn (+4) may act as oxidizers and as reducing agents.

Types of Manganese and its uses

It is found as a naturally occurring substance in soil and rocks of different types. It is found in low levels of water air, food and soil. There are different types of manganese which can be divided into two main types: organic and inorganic. Siliceous, ferruginous, aluminous, are few of them. Manganese deposits have been classified into deposits of oxidation manganese enriched zone and marine chemical sediments.

Uses

Manganese compounds are used in glass and ceramics industry, in the dyeing and printing industry, agriculture, etc. Steel is basic consumer manganese, spending an average of about 8-9 kg per 1 ton of manganese cast steel. For the introduction of manganese in steel is used more often than its alloys with iron - carbon ferromanganese (70 - 80% Manganese, 0.5 - 7.0% carbon, the rest being iron and impurities). Manganese is used in non-iron-based alloys. Manganese plating is used to protect metal products from corrosion.

Occurrence and Production

Manganese compounds naturally occurring in the environment such as soil and small solid particles in waterThe toxic dose for humans is 40 mg of manganese per day. The lethal dose for humans is not defined. The main attributes of manganese poisoning in animals are growth inhibition, loss of appetite, impaired iron metabolism and changes in brain function.

Reported cases of manganese poisoning in humans caused ...