Mining Engineering

Archaeological discoveries indicate that mining was conducted in prehistoric times. Apparently, the first mineral used was flint, which, owing to its concoidal fracturing pattern, could be broken into sharp-edged pieces that were useful as scrapers, knives, and arrowheads. During the Neolithic Period, or New Stone Age (about 8000–2000 bc), shafts up to 100 metres (330 feet) deep were sunk in soft chalk deposits in France and Britain in order to extract the flint pebbles found there. Other minerals, such as red ochre and the copper mineral malachite, were used as pigments.
The oldest known underground mine in the world was sunk more than 40,000 years ago at Bomvu Ridge in the Ngwenya Mountains, Swaziland, to mine ochre used in burial ceremonies and as body colouring. Gold was one of the first metals utilized, being mined from streambeds of sand and gravel where it occurred as a pure metal because of its chemical stability. Although chemically less stable, copper occurs in native form and was probably the second metal discovered and used. Silver was also found in a pure state and at one time was valued more highly than gold.
According to historians, the Egyptians were mining copper on the Sinai Peninsula as long ago as 3000 bc, although some bronze (copper alloyed with tin) is dated as early as 3700 bc. Iron is dated as early as 2800 bc; Egyptian records of iron ore smelting date from 1300 bc. Found in the ancient ruins of Troy, lead was produced as early as 2500 bc. One of the earliest evidences of building with quarried stone was the construction (2600 bc) of the great pyramids in Egypt, the largest of which (Khufu) is 236 metres along the base sides and contains approximately 2.3 million blocks of two types of limestone and red granite.
The limestone is believed to have been quarried from across the Nile. Blocks weighing as much as 15,000 kg (32,000 pounds) were transported long distances and elevated into place, and they show precise cutting that resulted in fine-fitting masonry. Great progress in mining was made when the secret of black powder reached the West, probably from China in the late Middle Ages.
This was replaced as an explosive in the mid-19th century with dynamite, and since 1956 both ammonium nitrate fuel-blasting agents and slurries (mixtures of water, fuels, and oxidizers) have come into extensive use. A steel drill with a wedge point and a hammer were first used to drill holes for placement of explosives, which were then loaded into the holes and detonated to break the rock. Experience showed that proper placement of holes and firing order are important in obtaining maximum rock breakage in mines.