Mechanical & Maintenance

Effect of Rare-Earth Metals on the Properties of Extruded Magnesium

The effects of rare-earth metals on the properties of sand-cast magnesium were discussed in some detail in earlier paper by the author. The present paper deals with the effect of the same alloying elements on the properties of extruded magnesium. This investigation also had as its aim the development of a wrought alloy having a … Read more

Fundamentals of Mixing and Agitation

Mixers are being applied with increasing frequency to problems in the metallurgical industries. The increase represents in part the modernization of mechanical equipment used through the application of unitized drives, modern electric motors and speed reducers, and recently developed materials of construction. Some applications have resulted from process changes and the use of techniques for … Read more

Earthquake Design for Metallurgical Plants

All persons and communities that have experienced strong-motion earthquakes are convinced of the importance and complexity of earthquake problems that must be solved in order to reduce the personal hazards and property losses to a reasonable minimum. It is also clear that absolute elimination of all risks is impossible. Reduction of existing hazards and precautionary … Read more

Comparison of 2400 and 4160 Volt Distribution Systems for Concentrators

Concentrating plants, in common with other types of industrial plants, cannot operate without, electric power. The electric distribution system and utilization equipments therefore, must be carefully considered in all phases of plant design. Two important aspects of proper distribution and usage of electric power are the selection of voltage levels and the methods of system … Read more

Selective Maintenance of Hydraulic Components on Mining Equipment

Commonly accepted maintenance methods are being outdated by the rapid acceptance and use of more complicated hydraulic circuitry on modern mining equipment. It is no longer adequate to use the maintenance program to merely repair or sustain equipment operation. Ever increasing operating costs place a huge premium on lost production time. It has therefore placed … Read more

Mill Design Economics

Talking about engineering economics in mill design reminds me of an old saying “There are several ways to handle women but nobody knows what they are.” I’m sure that the same economic factors do not apply to each of our mill designs, but for the sake of emphasis, it is well to review a few … Read more

Slurry Mass Flow Measurement

Advances in instrumentation now make it possible to measure accurately flow of such diificult-to-measure liquids as mining slurries. A mass flowmeter, which introduces no restrictions in the line, will measure the mass flow of slurry equal to the volume flow times the mass/unit volume. In the mass flowmeter system a volume flow measurement is electrically … Read more

Ropes for Drum and Koepe Friction Hoists

Four basic designs of ropes are now employed for hoisting duties: Six-strand, round strand ropes with fibre cores. Six-strand, triangular strand ropes with fibre cores. Non-rotating, multi-strand ropes. Locked coil ropes. Very solid and reliable ropes can be obtained with this simple geometric design of strand. Owing to the fact that the wires in the … Read more

Power Scale-Up for Agitating Slurries

An interesting problem with which the senior author has been concerned with is the scale-up of power requirements for slurry agitators operating in the laminar region with pseudo-plastic materials. Pulps of shaly ores, after various chemical reactions in aqueous leaching systems, are often difficult to settle and filter if agitation is violent. In these cases … Read more

Designing a Mill for Maintenance

Its purpose is to highlight the things that have been accomplished by the mill designers to lighten the load for the maintenance superintendent and to reduce the overall costs for the plant operator. The complexity of plant design, the civil and structural engineering problems encountered when the satisfactory maintenance layout is accomplished are appreciated, and … Read more