A mining machine is a device used to extract minerals or other geological materials from the earth. The exact workings depend on the type of mining and machine, but here’s an overview of how various mining machines work:

　　I. Different types of mining machines

　　1. Surface Mining Machines

　　- Draglines: These large machines have a bucket suspended from a long arm (boom). The bucket is dragged across the surface to collect materials such as coal or sand. The machine then lifts and dumps the material into a designated area.

　　- Bucket-wheel Excavators (BWE): These massive machines use a large rotating wheel fitted with buckets to scoop up material from open-pit mines.

　　- Bulldozers and Scrapers: Often used in surface mining to remove overburden (the layer of soil and rock covering a mineral deposit), bulldozers push material away, and scrapers remove it.

　　2. Underground Mining Machines

　　- Continuous Miners: Used in coal mining, these machines have large rotating drums equipped with teeth that grind the coal from the seam. The coal is then transported via conveyor systems out of the mine.

　　- Longwall Mining Machines: In this method, a rotating shearer moves back and forth across a long wall of coal, slicing off chunks. Hydraulic shields protect the miners and machinery from cave-ins.

　　- Drill Rigs: In hard rock mining, drill rigs are used to drill holes in the rock for blasting, after which the blasted rock is removed by loaders or haul trucks.

　　3. Hydraulic Mining Machines

　　- Hydraulic Monitors: These use high-pressure water jets to dislodge minerals from sediment. The water carries the loosened material into a sluice, where the valuable minerals are separated from waste.

　　4. Crushing and Screening Machines

　　- Jaw Crushers: These machines break up large rocks into smaller ones. They have two jaws—one stationary and one movable—that crush the rock between them.

　　- Cone Crushers: These use a rotating cone inside a fixed bowl to break rocks into smaller pieces by compression.

　　- Vibrating Screens: After crushing, vibrating screens are used to separate different-sized particles by size.

　　II. Workflow in Mining Operations:

　　1. Preparation: Clearing or blasting to access the mineral deposit.

　　2. Excavation: The mining machine extracts material.

　　3. Material Handling: Conveyors or trucks transport the extracted material for processing.

　　4. Processing: Crushers, screens, and mills reduce the material to usable size or separate minerals from ore.

　　Each type of mining machine is designed for specific types of minerals and mining conditions, and modern machines often include automation to enhance safety and efficiency.