In 1848, William Easby was granted a patent for a method of converting fine coal into solid lumps. In his application, Easby made only one claim: “The formation of small particles of any variety of coal into solid lumps by pressure.” In an equally brief description of the process, he mentions, “The utility and advantage […]
Рубрика: The History of Grinding
Multiple-Compartment Tube Mills
Starting in the late 19th century, particularly for grinding in the cement industry, tumbling mills were built in which a short ball mill was attached to a tube mill to make a single mill with a division head separating it into two compartments. Large balls were charged to the coarse grinding compartment. Worn balls in […]
PIN MILLS
Medium-Speed Mills A “soft size reduction” mill named the Triumph mill was made by Alpine in 1898 for preparing foodstuffs, animal fodder, and chemicals. The pin mill used the same principle as the colloid mill but with a lower speed of rotation. Figure 8.5 is the front page of the 1903 sales brochure. This was […]
EXPLOSIVES IN THE MID-19TH CENTURY
By this time, the Industrial Revolution was increasing the speed of social change; buildings and civil works were proceeding apace, and breaking and moving rocks was becoming a big business. Tunnels, roads, and canals had to be built through rocky terrains, quartz and limestone had to be mined to meet the needs for aggregate and […]
THE PREVALENCE OF SIZE REDUCTION
Size reduction is not only the most ancient technology, it is also the most widespread. It is used in every country and in every industry that involves solid particles. Here are some of the more important applications of the technologies we profile in this book: ■ Breaking wheat grains to separate endosperm from bran and […]
Hammers and Gads and Fire Setting
In early human history, rocks used for buildings, monuments, or metal extraction were mined by hand using hammers, levers, and wedges made from stone, wood, or bone. FIGURE 3.14 Hammer and gad mining: (a) 15th-century woodcut (Agricola 1950) (b) 18th — century drawing by Eduard Heuchler showing mining and manual breakage. One exhausted miner is […]
Cone Crushers
Compared to the gyratory crusher, the cone crusher is characterized by its higher speed and a flat crushing chamber design, which is intended to give a high capacity and reduction ratio for materials suitable for this type of processing. The aim is to retain material longer in the crushing chamber to do more work on […]
High-Pressure Grinding Rolls
The high-compression roller mills used in cement plants in the 1980s were similar in principle to the double-roll compactors built in the 1850s and 1950s, although apparently the only compactor used as a high-compression mill at that time was a secondhand unit installed by the Fuller Company in its laboratory as a test unit for […]
TUMBLING MILLS, PATENTS, AND LAWSUITS
In the mid-1890s, lawyers became interested in tumbling mills. In 1891, a patent specification was lodged with the Imperial Patent Office of the German Reich (Scheibe 1993) in which priority was claimed for the use of solid metal sections rather than screens on the cylindrical part of the mill. The purpose of the invention was […]
BALL MILLS WITH FIXED SHELLS AND HIGH-SPEED STIRRERS
Vertical Peg Mills After World War II, Netzsch-Feinmahltechnik GmbH, which had been established in Bavaria, Germany, in 1879 by two brothers to design and build machinery for the region’s ceramic industry, took advantage of the rapid postwar recovery to diversify its product range and built processing machines such as filters, mills, and pumps. Its engineers […]