Manganese is a silver metallic element with an atomic number of 25 and a chemical symbol of Mn. It is not found as an element in nature. It occurs in many different kinds of minerals such as manganite, purpurite, rhodonite, rhodochrosite, and pyrolusite. It is also found in many mineraloids such as psilomelane and wad.
Elemental manganese readily combines with oxygen, carbon, and silicon to form a long list of manganese minerals. Manganese ores generally contain 25 to 45 percent manganese, mostly in oxide (or hydroxide) and carbonate minerals.
Manganese ores are widespread, but most of the world’s supply is from a small number of manganese mining districts. Most manganese ores are from extensive layers of manganese-rich sedimentary rocks that formed in ancient oceans under specialized conditions. These occurred when changes in the oxidation state of ocean water first caused high concentrations of dissolved manganese and later precipitated various manganese minerals that became concentrated on the seabed. These layers are now found within the bedrock of continents.
Malachite is a green copper carbonate hydroxide mineral with a chemical composition of Cu2(CO3)(OH)2. It was one of the first ores used to produce copper metal. It is of minor importance today as an ore of copper because it is usually found in small quantities and can be sold for higher prices for other types of use.
Malachite has been used as a gemstone and sculptural material for thousands of years and is still popular today. Today it is most often cut into cabochons or beads for jewelry use.
Malachite has a green color that does not fade over time or when exposed to light. Those properties, along with its ability to be easily ground to a powder, made malachite a preferred pigment and coloring agent for thousands of years.
Malachite is a mineral that forms at shallow depths within the Earth, in the oxidizing zone above copper deposits. It precipitates from descending solutions in fractures, caverns, cavities, and the intergranular spaces of porous rock. It often forms within limestone where a subsurface chemical environment favorable for the formation of carbonate minerals can occur. Associated minerals include azurite, bornite, calcite, chalcopyrite, copper, cuprite, and a variety of iron oxides.
Some of the first malachite deposits to be exploited were located in Egypt and Israel. Over 4000 years ago, they were mined and used to produce copper. Material from these deposits was also used to produce gemstones, sculptures, and pigments. Several large deposits in the Ural Mountains of Russia were aggressively mined, and they supplied abundant gem and sculptural material in the 1800s. Very little is produced from these deposits today. Much of the malachite entering market today is from deposits in the Democratic Republic of the Congo, Chile and Brazil. Smaller amounts are produced in Australia, France, and Arizona.
Chalcopyrite is a brass-yellow mineral with a chemical composition of CuFeS2. It occurs in most sulfide mineral deposits throughout the world and has been the most important ore of copper for thousands of years. The surface of chalcopyrite loses its metallic luster and brass-yellow color upon weathering. It tarnishes to a dull, gray-green color, but in the presence of acids the tarnish can develop a red to blue to purple iridescence.
The iridescent colors of weathered chalcopyrite attract attention. Some souvenir shops sell chalcopyrite that has been treated with acid as "peacock ore." But, "peacock ore" is a more appropriate name for the mineral bornite.
The most obvious physical properties of chalcopyrite are its brassy yellow color, metallic luster, and high specific gravity. These give it a similar appearance to pyrite and gold. Distinguishing these minerals is easy. Gold is soft, has a yellow streak and has a much higher specific gravity. Chalcopyrite is brittle and has a greenish gray streak. Pyrite is hard enough that it cannot be scratched with a nail, but chalcopyrite is easily scratched with a nail.
The name "fool's gold" is most often associated with pyrite because it is more common and more often confused with gold. Chalcopyrite is also confused with gold, so the name "fool's gold" is also applied and appropriate.
The only important use of chalcopyrite is as an ore of copper, but this single use should not be understated. Chalcopyrite has been the primary ore of copper since smelting began over five thousand years ago. Some chalcopyrite ores contain significant amounts of zinc substituting for iron. Others contain enough silver or gold that the precious metal content more than pays the costs of mining.
Today, Brasil Mineração has a supply capacity of up to 5,000MT every 30 days. Our supply has a first world structure where it is possible to make the particle size separation of the ore into three conveyors, between sinter feed, fines and lump. With this, we can meet the demands of our customers, always striving for excellence of supply.