Grinding Circuit Simulation

These programs and the simulation algorithms are discussed below. Note that in some Grinding Circuit Simulations, a residence time distribution model is used. In the MRRC simulation package, however, only the two extremes of well mixed and plug flow through the mill are considered. This approach reduces the amount of input information and computation required […]

Laboratory Regrind Mill

A laboratory stirred ball mill was used in a batch manner, with the milling time being varied so as to produce a number of different product size distributions diameter ratio of one, and has a jacket through which cooling water is passed. The vessel is mounted on a turntable which is located on a thrust bearing. The turntable is restrained […]

SAG Semi-Autogenous Mill Steel Consumption

sag-steel-consumption-liner-nomenclature

Does a SAG Mill reduce steel consumption? Do SAG mills cost less to operate compared to conventional rod or ball mill grinding circuits? Mining companies are always searching for new ways to cut costs. In order to be competitive and justify the tremendous capital costs of new projects, there has been a strong trend toward […]

Rod Mill Grinding

holdup on feed rate

A detailed experimental study of breakage kinetics in a batch rod mill indicates that while the system is inherently nonlinear, the feed disappearance kinetics for the finer sizes and the coarser sizes at high holdups is well represented by first-order behavior. The set of breakage distribution functions was found to be normalizable and independent of […]

Ni-Hard Grinding Balls

Through a cooperative agreement, the Carondolet Foundry Co. of St. Louis, Mo., supplied 1,000 pounds of 2-inch Ni-hard balls for comparison with balls of other composition. Ni-hard balls are said to contain 2.5 to 6 percent nickel and 0.5 to 1.5 percent chromium. They have a Brinell hardness of 548. The company also furnished a […]

Grinding with Pebbles VS Steel Balls

Operators in the metallics industry, sometimes forget that pebble mills are an important factor in fine grinding. However, pebble mills are not extinct, as is shown by reference to a recent paper on ore milling, wherein it was shown that five of the 44 so-called “ball” mills mentioned actually were pebble mills. If the nonmetallics […]

Why use Different Size Balls in a Mill

Several years ago, Davis assumed that the rate of wear of the different sizes of balls in a ball mill was directly proportional to the weight of each ball, and he evolved a formula for calculating a balanced charge. Operators have used this formula when purchasing balls for a new mill or when reloading an […]

Impact of Ball Mills Diameter VS Length Compared Efficiency

Operators may rightly ask how much reliance should be placed on laboratory ball milling when they are using mills so much larger. This question was foremost in the earliest work at Rolla; in fact, in the beginning more attention was given to plant tests than to laboratory tests. The operators had calculated their results in […]

Grinding Efficiency of Ball Chips VS new Balls Compared

Battered Reject Balls and New Spherical Balls Compared: Operators are sometimes at a loss to know when a mill should be dumped to discard the worn and battered balls. Similarly, the present authors found an unknown variable when they compared the laboratory work of a new grinding medium with the plant performance of media, some […]