Our partner from Iran also produces ferromanganese, ferro molybdenum, nepheline syenite, demantoids, phosphate rock, selenium, shell, andalusite, rockwool, garnet, gabbro, diorite, vermiculite, attapulgite, calcium, barium, rare earth elements, scandium, yttrium and zeolite, and had the capacity to mine onyx.
MINERAL MATRIALS – ZINC
Zinc is a chemical element with the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. In some respects zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earth’s crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral.
LEAD – MINERAL MATRIALS
Lead (/lɛd/) is a chemical element with atomic number 82 and symbol Pb (from Latin: plumbum). It is a soft, malleable, and heavy metal. Freshly cut solid lead has a bluish-white color that soon tarnishes to a dull grayish color when exposed to air; the liquid metal has shiny chrome-silver luster. Lead’s density of 11.34 g/cm3 exceeds that of most common materials. Lead has the second highest atomic number of all practically stable elements. As such, lead is located at the end of some decay chains of heavier elements, which in part accounts for the relative abundance of lead: it exceeds those of other similarly-numbered elements.
Lead is a post-transition metal, and is relatively inert unless powdered. Its weakened metallic character is illustrated by its general amphoteric nature: it and its oxides react with both acids and bases. It also displays a marked tendency toward covalent bonding. Its compounds are most commonly found in the +2 oxidation state, rather than +4, unlike the lighter group 14 elements. Exceptions are mostly limited to organolead compounds, where the positive charge on lead is dispersed and stabilized. Like the lighter group 14 elements, lead shows a tendency to bond to itself, forming complicated chain, ring, or polyhedral structures.
Lead is relatively easy to extract, and the metal was known to prehistoric people in Western Asia. While its softness and dullness prevented it from high demand, galena—a principle ore of lead—often bore silver in it, which helped initiate production of lead. Lead production peaked in ancient Rome, and lead became easily available to common people. After the fall of Rome, levels of lead production fell, and those of Rome were not surpassed anywhere until as late as the Industrial Revolution. The metal was established as poisonous as late as in the late nineteenth century, which led to its eventual displacement from many uses, and it has been or is being phased out from those which include immediate contact to people.