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Rare metals and rare earths
Rare earths of a lanthanum subset, or lanthanides, are applied in production of permanent magnets, in iron and steel industry and non-ferrous metallurgy, in nuclear, electronic, chemical and other industries. |
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Non-metals
Non-metals are chemical elements that form simple elements with no
metal-specific qualities. Non-metals typically include 22 elements: gases - hydrogen,
nitrogen,
oxygen, fluor, chlorine and inert gases; liquids - bromine; solids - boron, carbon,
silicon, phosphorus,
arsenic, sulphur,
selenium, tellurium, iodine, astatine. |
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It is known, that silicium (its dioxide) builds carcass basics in some sea organisms – radiolarians, diatoms, some sponges, and sea stars. It is also known, that plants need it: from grains and sedge to palms and bamboo. The firmer the plant stem, the more silicium is found in the Ashes. Many laboratories in the world are busy with synthesis and analysis of the biologically active compounds of silicium.
Silicium is bound to oxygen in many natural compounds. Silica (in all its variations) makes 12% of the earth crust mass. Silicates and alum silicates come to even bigger proportion: 75% of the earth crust mass contains compounds of silicium, oxygen and other elements, aluminium in the first place.
Alloy of silicium and iron – ferrosilicium – is widely used in the ferrous metallurgy and for production of the acid-resisting items. This alloy is prepared through baking a mixture of silicium dioxide, carbon and iron ore in blast and electric furnaces. Ferrosilicium with 15% Si is very acid resistant, with the exception in case of the chlorohydric acid. There should be not less than 50% Si in ferrosilicium to make it resistant against this acid also. back |
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