Editing Mining engineering (section)

===Surface mining===
[[Surface mining]] comprises 90% of the world's mineral tonnage output. Also called [[Open-pit mining|open pit mining]], surface mining removes minerals in formations near the surface. Ore retrieval is done by material removal from the land in its natural state. Surface mining often alters the land's characteristics, shape, [[topography]], and geological makeup.

Surface mining involves quarrying and excavating minerals through cutting, cleaving, and breaking machinery. [[Explosives]] are usually used to facilitate breakage. Hard rocks such as limestone, sand, gravel, and slate are generally quarried into benches.

Using mechanical shovels, track dozers, and front-end loaders, strip mining is done on softer minerals such as clays and phosphate removed. Smoother coal seams can also be extracted this way.

With [[placer mining]], dredge mining can also remove minerals from the bottoms of lakes, rivers, streams, and even the ocean. In addition, [[in-situ]] mining can be done from the surface using dissolving agents on the ore body and retrieving the ore via pumping. The pumped material is then set to leach for further processing. Hydraulic mining is utilized as water jets to wash away either overburden or the ore itself.<ref>Ernest Bohnet, SME: ''Mining Engineering Handbook'', 2nd ed., Volume 2, 1992, "Surface Mining: Comparison of Methods," pp. 1529–1538, {{ISBN|0-87335-100-2}}</ref>