Tailings waters, chemical

Copper concentration Copper ore, water, chemical reagents, thickeners Flotation wastewaters Tailings containing waste minerals such as limestone, and quartz... 

Oil and Water Content without Solids. The presence of solids in an emulsion system reduces the characterization options because techniques that can quantify all three phases are not readily available. In many situations, however, only quantification of water in the oil product or oil in the tailings water is important. In other cases, the solids content is insignificant. In these situations, the range of techniques available is much more extensive and, in general, more applicable to field and on-line applications. Obviously, the methods discussed earlier also apply to these systems, along with a variety of spectroscopic and chemical analytical techniques. 

The tables in this section present thermodynamic data and equilibria for aqueous species and solids of iron and sulfur and equations for constructing Eh-pH and Eh-concentration diagrams, and chemical analyses of some acid mine waters and tailings waters. 

TABLE A12.4 Chemical analyses of some acid mine waters, tailings waters, and a wastewater (tailings solution)... 

The main sources of inorganic ions found in tailings water are (1) oil sand connate water (water in the spaces between the sand grains), (2) makeup water taken from the Athabasca River for use in plant processes, and (3) chemicals added during hot water extraction and other processes. These sources contribute ions that accumulate in the pond water that is recycled to oil sands processing. 

While most vesicles are formed from double-tail amphiphiles such as lipids, they can also be made from some single chain fatty acids [73], surfactant-cosurfactant mixtures [71], and bola (two-headed) amphiphiles [74]. In addition to the more common spherical shells, tubular vesicles have been observed in DMPC-alcohol mixtures [70]. Polymerizable lipids allow photo- or chemical polymerization that can sometimes stabilize the vesicle [65] however, the structural change in the bilayer on polymerization can cause giant vesicles to bud into smaller shells [76]. Multivesicular liposomes are collections of hundreds of bilayer enclosed water-filled compartments that are suitable for localized drug delivery [77]. The structures of these water-in-water vesicles resemble those of foams (see Section XIV-7) with the polyhedral structure persisting down to molecular dimensions as shown in Fig. XV-11. 

Another important class of materials which can be successfiilly described by mesoscopic and contimiiim models are amphiphilic systems. Amphiphilic molecules consist of two distinct entities that like different enviromnents. Lipid molecules, for instance, comprise a polar head that likes an aqueous enviromnent and one or two hydrocarbon tails that are strongly hydrophobic. Since the two entities are chemically joined together they cannot separate into macroscopically large phases. If these amphiphiles are added to a binary mixture (say, water and oil) they greatly promote the dispersion of one component into the other. At low amphiphile... 

Amphiphilic molecules (surfactants) are composed of two different parts hydrophobic tail and hydrophilic head [1 ]. Due to their chemical structure they self-assemble into internal surfaces in water solutions or in mixtures of oil and water, where the tails are separated from the water solvent. These surfaces can form closed spherical or cylindrical micelles or bicontinuous phases [3,5]. In the latter case a single surface extends over the volume of the system and divides it into separated and mutually interwoven subvolumes. 

Geomembrane These liners chiefly provide impermeable barriers. They can be characterized as (1) solid waste containment hazardous landfill, landfill capping, and sanitary landfill (2) liquid containment canal, chemical/brine pond, earthen dam, fish farm, river/coastal bank, waste-water, and recreation (3) mining, leach pad and tailing ponds and (4) specialties floating reservoir caps, secondary containment, tunnel, erosion, vapor barrier, and water purification. Plastics used include medium to very low density PE, PVC, and chlorosulfonated PE (CSPE). (The Romans used in their land and road constructions what we call geomembrane.)... 

Toxic pollutants found in the mercury cell wastewater stream include mercury and some heavy metals like chromium and others stated in Table 22.8, some of them are corrosion products of reactions between chlorine and the plant materials of construction. Virtually, most of these pollutants are generally removed by sulfide precipitation followed by settling or filtration. Prior to treatment, sodium hydrosulfide is used to precipitate mercury sulfide, which is removed through filtration process in the wastewater stream. The tail gas scrubber water is often recycled as brine make-up water. Reduction, adsorption on activated carbon, ion exchange, and some chemical treatments are some of the processes employed in the treatment of wastewater in this cell. Sodium salts such as sodium bisulfite, sodium hydrosulfite, sodium sulfide, and sodium borohydride are also employed in the treatment of the wastewater in this cell28 (Figure 22.5). 

Surface active agents, more commonly known as surfactants, are the groups of chemical compounds that in the most common form constitute an ionic or polar portion (hydrophilic head) and a hydrocarbon portion (hydrophobic tail). The ionic or polar portion interacts strongly with the water via dipole-dipole or ion-dipole interactions and... 

The uranium mine tails contain the equal masses of water and solids. Furthermore the treatment of each ton of uranium ore is accompanied by receiving about 3 tons of rafinate, and finally the treatment of 1 ton of uranium ore gives about 4 tons of liquid wastes of different chemical composition, which in turn depends on the treatment technology. 

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