PT.ANDALAS TETRA JAYA, PT.NEO
GREISEN MINERAL (has served in Manganese Mine since first of
2008), PT.ANDALAS PERSADA MANDIRI has served in Dolomite &
Calcite mine, and PT.NEO FERRO MINERAL has served in Iron Ore
Manganese is a chemical element
that is designated by the symbol Mn and has an atomic number of 25.
It is found as the free element in nature (often in combination with
iron), and in many minerals. The free element is a metal with
important industrial metal alloy uses. Manganese ions are variously
colour, and are used industrially as pigments and as oxidation
Iron Ores are rocks and minerals
from which metallic iron can be economically extracted. The ores are
usually rich in iron oxides and vary in colour from dark grey, bright
yellow, deep purple, to rusty red. The iron itself is usually found
in the form of magnetite (Fe3O4), hematite (Fe2O3), goethite,
limonite or siderite. Hematite is also known as "natural ore".
name refers to the early years of mining, when certain hematite ores
contained 66% iron and could be fed directly into iron making blast
furnaces. Iron ore is the raw material used to make pig iron, which
is one of the main raw materials to make steel. 98% of the mined
iron ore is used to make steel.
Kieserite is a highly unstable
magnesium sulfate mineral (MgSO4ĚH2O). It has a vitreous luster and
it is coloruless, greysh-white or yellowish. Its hardness is 3.5 and
it has a monoclinic crystal system.