The slag loader commonly used in tunnel wells, also known as rock loader, is now replaced by backhoe loader (bucket slag loader). It is required to be small in size, sturdy and durable, easy to operate, easy to walk, high production efficiency, continuous and non-intermittent operation, and safe and environmentally friendly. There are three walking modes of slag loader (rock loader): tire type, track type and crawler type. According to the arm bucket type of the slag loader, it can be divided into four types: bucket type; crab claw type; vertical claw type; bucket type. The first three are gradually eliminated and replaced by the bucket type in construction practice. Intermittent can not be continuous, reciprocating inflexible, low working capacity, unsafe caused by large dust, inhumane operation, small rock size requirements, limited slope and other defects.

The tire-type slag loader is a small model that is only suitable for working in a space of 1.7 meters, and can only work in level roadways. Problems such as scratching the tires, the efficiency is low, and the feeding force is small; its advantage is that the ultra-small space is loaded with slag and ore, and the price is the cheapest but more cost-effective than labor. The rail-type slag scraper is suitable for rail transportation and is more economical, but its working range is limited, and it is troublesome to lay the rails and can not work on the slope; its advantages are moderate price, high efficiency, and large feeding force. The steak is big and plentiful. The crawler slag loader combines all the above advantages and disadvantages, but the initial investment is more expensive, but the benefits are greatly doubled, and the construction period cost is reduced to the existing lowest point.