Under natural conditions, inorganic substances that are composed of the same chemical composition and physical properties in nature are called minerals. The main elements constituting various minerals are oxygen, silicon, aluminum , iron , calcium, potassium, magnesium, and the like. The earth's crust is made up of rocks, which are made up of minerals, which are made up of one or more chemical elements.
Various minerals in the earth's crust, where the use mining, washing and smelting and other modern technology to extract economy and national defense or metallic mineral products, call the ore required for each department.
Extract metals ores called metal ores, such as iron ore, copper ore and the like; extract non-metallic elements, minerals or ore directly called non-metallic minerals, such as phosphorus, asbestos, mica, lime and the like.
Ore is divided into rich ore and lean ore according to the grade of its grade; it is divided into simple ore and comprehensive ore according to the number of useful components that can be utilized.
Concert Ukulele,Ukulele Luna,Hricane Ukulele,Koa Ukulele
Shandong Changyun Musical Instruments Co., Ltd. , https://www.cyukulele.com