Хонинговальные головки

Figure 7.18 shows three types of classifying liners. As clinker grinding mills increased in length, it became necessary to devise a system by which the coarse balls were continu­ally thrown back to where the coarsest particles of ore were at the feed end of the com­partment. Hardinge had designed his “tricone” mill for this purpose, […]

Vibrating Mills One method of keeping balls in motion so that they will collide and break particles trapped between them is vibration, and a vibrating ball mill was developed and patented in Germany in the 1930s. Vibrating ball mills are either vertical or horizontal and can be used as continuous flow or batch mills, and […]

As Table 10.1 shows, there was a spectacular rise in consumption of ammonium nitrate explosives during the 1960s. This was the start of the ammonium nitrate-fuel oil (ANFO) era in industrial explosives, which is expected to continue well into the future. Ammonium nitrate was made by J. R. Glauber in 1659 (DuPont 1980). Its explosive […]

Friedrich Kick was born in Vienna in 1840. After graduating from the Vienna Polytechni — kum in 1862, he became professor of mechanical technology at the Technical University in Prague, Bohemia, where he worked from 1865 to 1892, including three terms as rector. From 1892 to 1910, he was a professor at the Technical University […]

Historically, the wind has also been an important source of renewable energy for driving grinding mills. “Crude vertical-axis panemones have ground grain in the Afghan high­lands since the seventh century” (Gipe 1995). Panemones had walls to direct the wind past vertical sails that were attached to a rotating axle, as shown in Figure 4.7. Windmills […]

In hammer mills the impact of a fast-moving hammer on a slow-moving rock causes shattering. It can also be caused by the collision of a rock traveling at high velocity with another rock or a breaker plate. This is the concept of a vertical-shaft impact crusher. FIGURE 5.19 Sectional view of the hammer mill (McGrew […]

Regardless of the category, all tumbling mills operate on the same principles: ■ The total weight of the charge in the mill—the sum of the weight of the grinding media, the weight of the material to be ground, and any water in the mill—is a function of the percentage of the volume of the mill […]

Most of the grinding of coal for combustion burners is performed in roller mills, but air — swept dry-grinding ball mills operating in closed circuit with separators are also used. Coal is fed to the ball mill with heated air. The air is drawn through the mill by a fanlocated in the classifying section. The […]

Another method of keeping balls in motion at high speed is nutation, which is similar to the oscillation of a spinning top. The nutating action, shown in Figure 8.9, is used by the Hicom mill. The grinding chamber is a truncated cone with a roughly hemispherical base, on a vertical axis of symmetry. The chamber […]

An initiation system starts the detonation of the main charge, after which firings should occur at the exact times that are planned to ensure best results. As discussed earlier, the objective of initiation systems during the black powder and dynamite eras was to improve the safety of explosives. By 1900, the first electric delay detonator […]