Хонинговальные головки

Philetus Gates was one of several inventors who patented rudimentary designs incorpo­rating the idea of a circular crusher between 1860 and 1878, but it was not until 1881 that he patented a successful gyratory crusher (Dickinson 1945). Figure 5.11 shows how the original Gates crusher worked, and early models are shown in Figure 5.12. The […]

The Raymond mill had rollers attached to vertical shafts that were suspended from a horizontal beam through joints that allowed them to swing. Rotation of the beam caused the rollers to swing outward and press against the grinding ring. The feed was intro­duced into the grinding zone between the rollers and the ring, and the […]

Ball mills became the dominant fine-grinding machine in the 20th century. By 1900, the ball mill patent litigation in France had ended, and inventions to improve fine-grinding processes were in full flood. Inventing a machine is one thing, selling it another. One event that went far to establish the credibility of wet ball mills as […]

In those days all paints were ground in very small quantities by hand, and it was not unusual for an apprentice to work on a couple of ounces of paint for many months. In the age when few colours were known it was the colloidal grinding of paints that enabled the great artists of the […]

First Generation Dynamic air separators have several common characteristics: ■ Internal rotors that are also feed distribution plates ■ Airflows generated by internal or external fans ■ Collision blades that interrupt the flow and rejection of coarse particles FIGURE 9.11 Alpine Zig Zag classifier FIGURE 9.12 Askham air separator (Butler showing the passages and collision […]

Aggregates — hard, inert materials used for mixing in various-sized fragments with a cementing material to form concrete or mortar. Air separators — a machine where air is the carrying medium instead of water, and par­ticles are separated by centrifugal force. Static separators are similar in operation to hydrocyclones, but dynamic separators have internal rotating […]

As the world’s population steadily increased (see Table 1.1), so did the demand for con­verting raw materials into valuable commodities such as medicines, minerals, and pig­ments. By the start of the 20th century, these and other commodities were being produced in volumes of tons (see Table 1.2). Along with the spectacular increases in population and […]

His berries, nuts, acorns and corn were pounded into meal; and his invention of the first pounding appliance constituted, without doubt, one of the earliest attempts to devise an instrument useful in the peaceful arts. (Bennett and Elton 1898-1904) In this chapter we discuss how stones driven by muscle power—which were first used for grains […]

In 1895, Thomas Edison was responsible for a remarkable innovation in crushing. Edison believed that high-grade deposits of iron ores in the eastern United States were running out, and he decided to develop a deposit of low-grade ore containing magnetite at a treatment rate of up to 6,000 tpd. Minimizing mining and crushing costs was […]

Many roller mills were sold from 1930 to 1950, but there was little enthusiasm for new designs because of the economic depression and World War II. The revival of industry after the war increased the demand for materials, and new mills were required with grinding chambers that had higher processing capacities. Fixed Rollers and a […]