Ore can be divided into and lean ore according to grade.
举一反三
- Ore can be divided into oxide ore and sulfide ore according to chemical composition. A: 正确 B: 错误
- According to the dip angle of the ore body, the open-pit deposit can be divided into ( ). A: Horizontal and near horizontal deposits B: Gently inclined deposit C: Inclined deposit D: Steep deposit
- Which of the following is the ore breaking methods?( ) A: Artificial ore breaking B: Mechanical and hydraulic ore breaking C: Rock drilling and blasting D: The other three options all meet the requirements
- Which of the following statements is true?( ) A: The other three options all meet the requirements B: Leveling refers to leveling the surface of ore retention pile after local ore releasing. C: Prying roof means that the roof and two sides of loose ore rock should be pryed off when the site is leveled. D: Gravity ore drawing is generally adopted for local ore releasing
- According to the passage, how did Bessemer method make the mass production of steel possible A: It directed air at melted iron in a furnace, removing all impurities. B: It slowly heated iron ore then stirred it and heated it again. C: It changed iron ore into iron which was a substitute for steel. D: It could quickly find deposits of iron ore under the ground.