General knowledge about ore grades

General knowledge about ore grades
The grade of ore refers to the content of useful components in the ore. Generally expressed in mass percentage (%). Due to different types of minerals, the methods of expressing ore grade are also different. Most metal ores, such as iron, copper, lead, zinc and other ores, are expressed by the mass percentage of the metal element content; the grade of some metal ores is expressed by the mass percentage of their oxides, such as WO3, V2O5, etc. ; The grade of most non-metallic mineral raw materials is expressed by the mass percentage of useful minerals or compounds, such as mica, asbestos, potash, alunite, etc.; the grade of precious metal (such as gold, platinum) ores is generally expressed in g/t ;The grade of primary diamond ore is expressed in mt/t (or carat/ton, recorded as ct/t); the grade of placer ore is generally expressed in grams per cubic centimeter or kilogram per cubic meter.
The application value of ore is closely related to its grade. Ore can be divided into rich ore and poor ore according to grade. For example, if iron ore has a grade of more than 50%, it is called a rich ore, and if the grade is about 30%, it is called a poor ore. Under certain technical and economic conditions, the industrial grade of ore worth mining is usually specified, that is, the minimum industrial grade. Its regulations are closely related to the size of the deposit, ore type, comprehensive utilization, smelting and processing technology, etc. For example, copper ore can be mined if it reaches 5% or less, and vein gold reaches 1 to 5 grams/ton.
Industrial grade refers to the useful material that has economic benefits (can at least guarantee the repayment of various costs such as mining, transportation, processing and utilization) in a given block of single ore formation reserves in a single project (such as drilling or trenching). The lowest average content of the component. It is used to determine the economically recoverable or economically balanced grade, that is, the grade when the income value of the mined ore is equal to all input costs and the mining profit is zero. Industrial grade is constantly changing with the development of economic and technical conditions and the degree of demand. For example, from the 19th century to the present (2011), the industrial grade of copper mines has dropped from 10% to 0.3%, and even the industrial grade of some large open-pit copper deposits can drop to 0. 2%. In addition, industrial grades have different standards for different types of mineral deposits.