Хонинговальные головки

Each new generation of computers—particularly personal computers—increases the avail­ability of and the capabilities for creating simulations for all sizes and types of size — reduction processes and machinery. Computers will continue to be important tools in studying size reduction and in making the needed developments. Manufacturers of mechanical machines and electrical motors have demonstrated the […]

About 4,000 years ago, with the mortar and pestle proving unsuitable for the finer grind­ing needed for new commodities, the saddlestone mill was invented. Saddlestones use a horizontal fixed stone, over which the moving stone travels in a back-and-forth motion. This mill, which again relied on human muscles as the source of energy, was used […]

The advantage of dynamite was the high energy it delivered into the rocks to break them; its disadvantage was that it was dangerous to use. Melvin Cook, one of the great mining scientists and entrepreneurs of the 20th century, invented a range of safer, easier to handle, and easier to transport explosives based on ammonium […]

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 […]