Хонинговальные головки

For most of the 20th century, equipment manufacturers brought the main improvements to the technology of fine grinding. The Allis-Chalmers Company, for example, with its research programs and extensive publications, was a leading manufacturer of crushing and grinding machinery and one of the main contributors to better grinding technology. The Allis-Chalmers Company, then, is a […]

The first mills to produce fine particles at a rate of a few tons per hour were slow-speed ball mills and roller mills that were developed about 1880. By 1920, there was a strong demand for fine grinding as industry revived after World War I. By then the ball mill was so successful that for […]

We have described how the processes involved in grinding developed in unison with new forms of energy and better materials: muscle power and stone, water power and iron, steam power and steel, and electricity and alloy steels. Explosive energy is the fifth form of energy, which is used to break rocks and to prepare them […]

The 16th, 19th, and 20th centuries brought seminal changes in size-reduction technol­ogy. In each case, abundant new wealth encouraged the consumption of materials, investments in new plants, and the development of new processes and machines. This, in turn, increased the demand for size-reduction machinery with greater productivity and greater energy efficiency. In the 16th century, […]

The mortar proper rested on a stand whose height was such that its upper rim reached about to the knee of the worker, or else it and the stand were made of one piece. The pestle was made of wood about 30 to 39 inches long and narrowed down at the middle so that it […]

The incentive to build large primary gyratory crushers came in the 1920s with the devel­opment of open-pit mines for copper and iron ores. The aggregate producers’ demand for a machine that would control the size distribution and shape of pebbles at a high pro­duction rate offered the incentive to build cone crushers, which had specially […]

The MB mill was designed and built in 1947 by Max Berz, formerly head of the design department at von Grueber’s company. It had three large rollers that rotated in a track­ing groove and were pressed down by a thrust ring. The rollers were not fixed by roller bearings and could move relative to each […]

With the development of ball mills, studies were made to find improved means to pro­duce finer feed for ball mills. Double-roll crushers, gyratory crushers, and cone crushers were developed for this role. Using steel rods as the grinding media in tumbling mills was found to be an efficient means to make ball mill feed and […]

As early as 1928 people started turning the hollow cylinder of the ball mill to a vertical position and started using a slow running agitator to keep the ball charge moving. The idea was to produce a uniform acceleration of the balls so that nar­rower particle size grinds results. (Netzsch 1974) In stirred mills the […]

The era of explosives started with the invention of fireworks some time in the first mil­lennium AD. It is believed that fireworks started in China, one version being that they were created by the residents’ habit of building wood fires on top of saltpeter rocks. The heat caused chemical decomposition of the saltpeter, and this […]