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Mechanical separation, minerals

D Immobilized substrate where mineral to be removed is bound to a large substrate permitting simple mechanical separation Robotic manipulation... [Pg.94]

Figure 1-12 Control mechanisms of mineral dissolution in aqueous solutions. Data are from Berner (1978). A straight line is drawn to separate transport control and interface reaction control although there is no theoretical basis for whether the boundary should be linear. Almost without exception, those with transport control lie above a straight line, and those with interface reaction control lie below the line. The only significant departure from the rule is the dissolution of PbS04 (cross in the figure) that lies inside the region for the interface reaction control, but is actually controlled by both interface reaction and mass transport. Figure 1-12 Control mechanisms of mineral dissolution in aqueous solutions. Data are from Berner (1978). A straight line is drawn to separate transport control and interface reaction control although there is no theoretical basis for whether the boundary should be linear. Almost without exception, those with transport control lie above a straight line, and those with interface reaction control lie below the line. The only significant departure from the rule is the dissolution of PbS04 (cross in the figure) that lies inside the region for the interface reaction control, but is actually controlled by both interface reaction and mass transport.
Cadmium acetate is used in the pottery and porcelain industry for producing iridescent effects the borotungstate forms an aqueous solution of high density when concentrated (d = 3.28), useful in die mechanical separation of minerals and in density gradient techniques the bromide, like the zinc salt, is used in photography, process engraving and lithography. [Pg.998]

Froth flotation is an application of foams that is used to separate mineral components from each other based on their having different surface properties, typically their wettability and surface electrical charge. For example, froth flotation is the classic process used to separate copper from lead ore. The process involves having hydrophobic particles attach to gas bubbles which rise through a turbulent suspension to create a surface foam called a froth. Figure 10.2 shows an illustration of a mechanical flotation cell. This is the classic flotation device [53,91,625], First, the flotation feed particles are well dispersed into a particle suspension. Together with chemical flotation aids, such as collectors and frothers, this constitutes what is called the flotation pulp. In a mechanical flotation cell, air is fed in the form of fine bubbles and introduced near the impeller (see Figure 10.2). In addition to mechanical flotation cells, there are also pneumatic cells and cyclone flotation cells. Pneumatic... [Pg.246]

Another cleaner alternative consists in producing solid, liquid and gaseous fuels by pyrolysis. The solid fuel could be upgraded by mechanical separation of metals and minerals in order to produce a cheap feedstock to a classical gasifier. Moreover, selected additions during pyrolysis could entrap pollutants such as chlorine and heavy metals [1-3]. [Pg.252]

Phase. Commonly defined as a uniform, homogeneous, physically distinct, and mechanically separable part of a system. Unfortunately, mineral phases are often not uniform, homogeneous, or mechanically separable except in theory. Sophisticated microscopic and spectroscopic techniques and operational definitions are needed to define some mineral phases. [Pg.2295]

A phase is a restricted part of a system with distinct physical and chemical properties (Wood and Fraser 1976). A phase can also be defined as a physically and chemically homogeneous portion of a system with definite boundaries (Brownlow 1979). These attributes mean that a phase should be mechanically separable from a system. Example phases are minerals and well-mixed gases and liquids. Not true phases, because they are comprised of more than one mineral, are rocks such as granite or minerals such as the feldspars when they are chemically zoned and have spatially variable compositions. [Pg.2]

Wirtsch, Mayer, G., Stahl, W., Model for Mechanical Separation of Liquid in a Field of Centrifugal Force, Mineral Processing, 11 619-627... [Pg.589]

In general, pyrolysis of certain hypercrosslinked polystyrene materials at a temperature of about 600°C may result in interesting carbonaceous adsorbing materials with a yield of up to 55-60% within 50-60 min. The products maintain the spherical form of the initial materials and their overall texture, and acquire an exceptional mechanical strength of up to 8 kg per bead. They are basically nanoporous and show size-dependent adsorbing properties [207, 210]. In particular, they efficiently separate mineral ions in accordance with the new frontal ion size exclusion process... [Pg.290]

A phase is defined as a homogeneous body of matter having distinct boundaries with adjacent phases, and so is in principle mechanically separable from them. Each mineral in a rock is therefore a single phase, as is a salt solution, or a mixture of gases. [Pg.317]

The main commercial source of mica is pegmatite rock, where large books of mica can be hand separated from feldspar and quartz. Finer flake size mica is mechanically separated from deposits of schist where quartz is the main co-mineral. Large tonnages of mica are generated as a by-product of kaolin production and some of this fine particle size mica is separated by froth flotation. Another commercially important source is as a by-product from apatite (calcium phosphate) mining. [Pg.459]

One can sometimes choose between using a mass-transfer operation of the sort discussed in this book and a purely mechanical separation method. For example, in the separation of a desired mineral from its ore, it may be possible... [Pg.7]

Classed under this heading are media made from metal powder and fibres, ceramic powder and mineral wools, glass powder and carbon fibres (used for their mechanical separation ability, not as adsorbent). [Pg.63]

The treatments used to recover nickel from its sulfide and lateritic ores differ considerably because of the differing physical characteristics of the two ore types. The sulfide ores, in which the nickel, iron, and copper occur in a physical mixture as distinct minerals, are amenable to initial concentration by mechanical methods, eg, flotation (qv) and magnetic separation (see SEPARATION,MAGNETIC). The lateritic ores are not susceptible to these physical processes of beneficiation, and chemical means must be used to extract the nickel. The nickel concentration processes that have been developed are not as effective for the lateritic ores as for the sulfide ores (see also Metallurgy, extractive Minerals recovery and processing). [Pg.2]

Various techniques are available to separate the different types of particles that may be present in a sohd mixture. The choice depends on the physicochemical nature of the sohds and on site-specific considerations (for example, wet versus diy methods). A key consideration is the extent of the liberation of the individual particles to be separated. Particles attached to each other obviously cannot be separated by direct mechanical means except after the attachment has been broken. In ore processing, the mineral values are generally liberated by size reduction (see Sec. 20). Rarely is liberation complete at any one size, and a physical-separation flow sheet wih incorporate a sequence of operations that often are designed first to rejec t as much... [Pg.1755]


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See also in sourсe #XX -- [ Pg.146 ]




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