Хонинговальные головки

By 1890, 100 Krupp-Grusonwerk tumbling mills were operating in cement plants, and other companies were manufacturing them. One company that contributed much to the technology of tumbling mills was F. L. Smidth and Co. of Denmark. This company had been established as a one-man consulting engineering business by Frederik Laessoe FIGURE 7.5 Transporting an early […]

Mills and the materials used to build mills have to withstand the high stresses involved in each revolution of the mill with a complete reversal from maximum compression to maximum tension and back again. Mill design required a complete understanding of the stresses involved in one rotation of the mill. As the size of tumbling […]

The classification of very fine particles is carried out in many industries in air rather than water to avoid problems with chemical reactions of particles with water and with separa­tion of ultrafine particles from water and drying them. Some of the disadvantages of dry classification are that it requires ducts and processing equipment that are […]

The prospects for the future of size reduction cannot be precisely established. The his­tory and the questions facing those industries that use the technology, however, indicate the areas requiring study. Technology has always stepped up to meet the demand for size reduction. Educational and research facilities have been created to teach and to search for […]

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 […]