Froth flotation of minerals is one of the dominant concentration processes available today. By this process, finely divided mineral particles, within a pulp, separate according to the hydrophobicity of their chemically modified surfaces. Hydrophobic mineral particles are collected and transported from the pulp by air bubbles into the froth, along with some hydrophylic particles, which … Read more
Dust measurements in mines clearly indicated that the major mineral dust exposure is due to loading and transport of the ore from the mining areas. One approach to the solution of this dust problem is the application of water sprays to reduce dust dispersion. Wetting of broken rock is very effective in preventing fine dust … Read more
Ball mill shape factors in the period prior to 1927 averaged 1.1/1 for 29 center discharge mills and 1.0/1 for 30 peripheral discharge mills. With the resumption of new plant construction after the 1930’s depression, the Morenci concentrator continued the 1/1 ratio with its 3.1 x 3.1 m (10 x 10 ft) mills. The ratio … Read more
We present the results obtained in a study of the residence time distributions of solids and liquids in two and three phase systems in a column flotation cell. The effects of various flotation parameters on these residence time distributions of the collection and cleaning zones are also reported. The data obtained was fitted to various … Read more
Very few mineral properties spend their entire lifespans from discovery to depletion in the hands of one owner. More likely, properties will have several owners, and partial interests may change quite often. Similarly, mineral companies are bought and sold with frequency, in recent years at what appears to be an accelerating rate. The reasons for … Read more
Floatable and non-floatable particles follow different sequence for transport from the pulp to the froth and from the froth out of the cell. For floatable particles, the principal mechanism is true flotation (i.e. bubble attachment and levitatlon). Non-floatable particles arrive to the slurry-froth interface by hydraulic entrainment (i.e. wake carry over), mechanical entrainment (due to … Read more
Application of value engineering techniques to grinding process modelling led to the identification of two basic functions of the ball mill-classifier circuit. In terms of a specified circuit product size which is used to differentiate between “coarse” or oversize material and “fines” or undersize material, these basic functions are (a) breakage of the coarse material … Read more
These depressants are organic mixtures reacted with inorganic salts. They have found application for depression of oxidized pyrite, marcasite and pyrrhotite during the flotation of Cu, Cu-Zn, Cu-Pb-Zn and Pb-Zn ores. Some of these depressants have been adapted for depression of zinc during sequential copper zinc flotation. Depressants from the DS series have been successfully … Read more
The ultrasonic treatment unit consists of an inclined, flat bottomed metal trough, usually made of stainless steel or aluminum, with the ultrasonic transducer attached near the upper end. A typical unit would be 91.5 cm (36 inches) wide and 244 cm (96 inches) long. Figure 1 is a photograph of an ultrasonic treatment unit being … Read more
Carbon strip circuits present a particularly challenging scale inhibition problem. Many of the factors that tend to promote scaling are present in these systems. For example, carbon strip circuits are run at high temperatures, high pH levels, and require long batch cycle times. Tortuous paths are encountered by the strip solution circulating through heat exchangers, … Read more