Dynamic experiments were performed in a continuous open-circuit 40×40 cm ball mill using a pseudo-random binary sequence of the feed rate and measuring the variations of the discharge particle-size distribution. The impulse response is calculated by a cross- correlation technique. Then a model involving a discrete transfer function and a time-series stochastic equation is calibrated … Read more
A practical application of recent design concepts makes it possible to design a column cell to fit a specific set of conditions. The design and operating parameters of a column cell installation that replaced a conventional two stage copper flotation cleaning circuit at MAGMA COPPER COMPANY, SAN MANUEL, ARIZONA using these design concepts is described. … Read more
Cobalt-sulfide mineralization can be found in potentially economic quantities where permeable, basal Cambrian formations “pinchout” against Precambrian paleotopographic highs. These environments are common around the Saint Francois Mountains of southeastern Missouri and they share many similarities with the geologic environments of Zambia and Zaire in South Africa. Exploration Philosophy Exploring for cobalt-bearing minerals in southern … Read more
The process of magnetic separation is based on the differences among magnetic susceptibilities of various mineral species. Performed either wet or dry, the separation has application in both the recovery and concentration of value minerals, and in removing deleterious mineral constituents from a product stream. There are two major categories to be considered when addressing … Read more
A systematic, comprehensive, balanced approach is presented for underground coal mine design, capable of being standardized and generalized. This approach epitomizes professionalism and must preceed the physical product. Design involves a varied senior staff and requires extensive selective input data. Engineering follows a total systems approach, operating in and for a constricting geologic setting, heavily … Read more
When the Symons brothers invented the cone crusher over 60 years ago, they employed the principle wherein the length of the crushing stroke was related to the free fall of material by gravity. This permitted the material being crushed to fall vertically in the crushing chamber; and in effect caused the particles to be crushed … Read more
Much research has been carried out on biohydrometallurgy over these last 25 years and is still being actively conducted all over the world. The interdisciplinary nature of this young branch of science and technology is reflected by the variety of experts involved: microbiologists, mining engineers, hydrometallurgists, physico-chemists, mineralogists, solid-state physicists and bio-chemists. This intensive research … Read more
For grinding Portland Cement, the power consumption accounts for some 35% of the total consumption of electrical energy for producing cement, counting right from the quarry to the packing plant. It is therefore for very good reason that great efforts during the past years have been put into making cement grinding more efficient, thereby saving … Read more
Aqueous polydisperse suspensions of angular (milled) or spherical (atomised) ferrosilicon alloy powders are widely used in mineral, aggregate and scrap separation processes as a dense medium. Table I shows the typical range of Dense Media Separation water analyses (analysing the supernatant after allowing the ferrosilicon solids to settle) taken from three diamondiferous-kimberlite circuits, from which it … Read more
During operation of tailings impoundments, water is lost through decanting, evaporation and seepage. Techniques have been developed to regulate or control each of these components. Collectively implemented, these techniques form the basis of tailings impoundment management. Regulation of the rate and level of decanting influences the size of a free water pond, and, thereby, the … Read more