Хонинговальные головки

With the success of primary autogenous milling and feed control at Union Corporation, primary autogenous mills became an accepted feature of Rand grinding practice. The autogenous mill circuits required about 25% more power than conventional circuits using pebble mills, but the smaller crushing circuit meant that there was lower capital investment and reduced maintenance cost. […]

The history of cyclones goes back to 1891 when E. Bretney obtained the first patent (Bretney 1891). The Bretney cyclone was designed with a closed apex for intermittent discharge and was the forerunner to present-day desanders that are used for separating sand from water in pressurized water systems. The Bretney cyclone had a roof entry […]

Advances in drilling and blasting were always hard won, and the work was onerous and dangerous until well into the 20th century. Objectives of blasting during the 20th cen­tury were ■ Before 1960: to make excavation possible ■ 1960-2000: to make excavation efficient ■ After 2000: as part of the overall rock breakage process Much […]

Born in New Jersey in 1872, John Van Nostrand Dorr started work as a laboratory assis­tant in Thomas Edison’s laboratory in Orange, New Jersey, at the age of 16. At the time Edison had become heavily involved in mining and processing low-grade magnetite ores. Thinking that the iron ore deposits in the eastern United States […]

As the world’s population and its demand for minerals continued to grow, it became nec­essary to devise a machine that could crush abrasive ores to small sizes at higher rates and that could be driven using a renewable power source. Enter the stamp mill. Although water-driven trip hammers had been used in China for crushing […]

Roller mills were used in China in the 2nd century for grinding the red mineral cinnabar to a vermillion pigment (Figure 6.1) and for grinding grains for cereal (Figure 6.2), and they are still used for these purposes today (Figure 6.3). In 1449, Pietro Speciale was credited with the development of a three-roller mill in […]

Tumbling mills are built for either continuous or batch operation. In continuous mills, feed enters one end and broken product leaves the other. In batch mills, the material to be ground is charged to the mill, and the mill is closed and run until the material is ground. The mill is then stopped, the load […]

By 1960, autogenous grinding had become reality. Aerofall Mills Ltd. and the Hardinge Company had sold 50 mills worldwide; Dorbyl in South Africa and Allis-Chalmers in the United States had started manufacturing them; and Morgardshammar in Sweden and Tyazhmash in Russia would begin manufacturing them soon. The road had been long and difficult, but the […]

Most of the work in the mining industry up to 1950 was for dewatering or desliming. The big breakthrough application for the cyclone, however, was just around the corner. In 1951, metallurgists at the San Manuel operation of Magma Copper Corporation (San Manuel, Arizona) experimented with a specially designed cyclone for closed-circuit grinding. The results […]

Blasting is a complex process and many variables are involved. Consequently, a model of blasting that predicts fragmentation accurately is necessary to optimize total size-reduction systems. The first theory of blasting was proposed in 1792 and a model based on it was used to design blasts (Drinker 1888), but its objectives, details, and how well […]