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
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
举一反三
- 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
- Ore can be divided into oxide ore and sulfide ore according to chemical composition. A: 正确 B: 错误
- Which of the following is the most abundant solid mineral in the seabed?( ) A: Manganese nodule B: Nickel ore C: Copper mine D: Cobalt ore
- Ore can be divided into and lean ore according to grade.
- The main transport stage refers to the stage in which the ore mined in two or more stages is lifted to the ground.