Хонинговальные головки

In the early 1950s, cyclones were being used in the kaolin industry to separate the finest kaolin particles into products that could be sold at a premium. Their success gave a boost to cyclone technology and led to the design of small cyclones that could efficiently extract the very fine particles from the feed. This […]

The art of prophecy is very difficult, especially with respect to the future. —Attributed to Mark Twain NEW SCENARIOS FOR SIZE REDUCTION For more than 10,000 years, size reduction has been the unending effort to produce ever — larger volumes of flour for consumption, rocks and pebbles for building, and fine mineral particles for producing […]

Our colleagues—some of whom we have known for many years and some we have come to know recently through e-mail—have responded most generously to our requests for information and comments. We are grateful for all the assistance we received. We would like to extend our particular thanks to those colleagues who wrote or contributed to […]

Because the breakage environment is so different between laboratory and plant, size reduction is not a subject that readily lends itself to the classic technique of conducting basic research and then transferring the results to large-scale operations. But Professor Dr.-Ing Hans Rumpf showed that the links between empirical and fundamental knowledge could be understood through […]

In Cornwall in 1804, John Taylor at Wheal Travistock set up two discarded pump barrels in parallel (Barton 1961) as horizontal rolls to crush copper and tin ores for concentra­tion by gravity. This experimental crusher, which became known as “Cornish rolls,” was driven by a steam engine (Figure 5.8). The rolls were only one of […]

Figure 6.8 shows a ring-roller mill invented by F. E. Huntington in 1883 to grind gold­bearing quartz ores to liberate the gold before amalgamating it on tables. The Huntington mill was a roller mill similar to an arrastra, but centrifugal force, instead of gravity, drove its grinding action. It had three suspended flat rollers that […]

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 […]