Хонинговальные головки

CHIMPANZEES AND NUT CRACKING The history we give in this book begins at the start of agriculture, about 8000 bc, and it refers only to the activities of Homo sapiens. Size reduction, however, may actually have been pioneered long before that. For example, chimpanzees in some regions of West Africa have a culture of nut […]

Dr.-Ing Klaus Schonert studied under Rumpf at the University of Karlsruhe, where he used single-particle breakage to study comminution, studied air separators to close dry­grinding circuits in cement plants, and did his early studies on HPGRs. In 1968, he became the head of the university’s comminution group (Instituterfuer Aufberetung und Veredelung). Schonert’s research at the […]

The Blake crusher had its origin in a decision by the town council in New Haven, Con­necticut, in 1852 to build a 3.2-km road in the center of the town using the MacAdam process. Eli Blake was one of the townsmen responsible for planning the road, and he realized that the cost would be reduced […]

The Maxecon mill had a vertical grinding ring rotating around a horizontal axis and three convex horizontal rollers that rotated independently and were pressed against its FIGURE 6.9 Diagrams of ring-roller mills: (a) Chilean mill in which a vertical shaft rotates heavy cylindrical rollers around a plane ring race (b and c) Loesche mills and […]

After 1900 the grinding of Portland cement raw material and of cement clinker required large numbers of tumbling mills. This was also the heyday of gold min­ing. The old stamp mills that were used in great numbers for grinding gold ore did not grind sufficiently fine to liberate all of the gold, and the new […]

The working surfaces of crushers and grinding mills are lined with wear-resistant materi­als to protect the permanent parts. The history of wear protection is an integral part of the history of comminution, because it is a major factor in the operating costs for cir­cuits. Replaceable surfaces were used as early as the 1880s in South […]

An early invention was a static air separator in which there are no moving parts and clas­sification occurs by changes in air velocity and direction. Figure 9.8 shows the method of operation of a cone-type separator. The air stream (C) carrying the particles is converted from a directional flow through the outer cone into a […]

Each new generation of computers—particularly personal computers—increases the avail­ability of and the capabilities for creating simulations for all sizes and types of size — reduction processes and machinery. Computers will continue to be important tools in studying size reduction and in making the needed developments. Manufacturers of mechanical machines and electrical motors have demonstrated the […]

About 4,000 years ago, with the mortar and pestle proving unsuitable for the finer grind­ing needed for new commodities, the saddlestone mill was invented. Saddlestones use a horizontal fixed stone, over which the moving stone travels in a back-and-forth motion. This mill, which again relied on human muscles as the source of energy, was used […]

The advantage of dynamite was the high energy it delivered into the rocks to break them; its disadvantage was that it was dangerous to use. Melvin Cook, one of the great mining scientists and entrepreneurs of the 20th century, invented a range of safer, easier to handle, and easier to transport explosives based on ammonium […]