Halite, NaCl

Second, at a given saturation index, supersaturated minerals with high solubilities have the potential to precipitate in greater mass than do less soluble ones. Consider a solution equally supersaturated with respect to halite (NaCl) and gypsum (CaS04-2H20). Of the two minerals, halite is the more soluble and hence more of it must precipitate for the fluid to approach equilibrium. 

As a test of our ability to calculate activity coefficients in natural brines, we consider groundwater from the Sebkhat El Melah brine deposit near Zarzis, Tunisia (Perthuisot, 1980). The deposit occurs in a buried evaporite basin composed of halite (NaCl), anhydrite (CaSC>4), and dolomite [CaMg(CC>3)2]. The Tunisian government would like to exploit the brines for their chemical content, especially for the potassium, which is needed to make fertilizer. 

Af is called a formation or stability constant. Note that the formula for the ion pair, NaQ (aq), symbolizes the interaction of 1 atom of Na with 1 atom of Cl, whereas the representation of crystalline halite, NaCl(s), is an empirical formula in which an imspecified number of Na and Cl atoms are present in a 1 1 stoichiometric ratio. 

Halogenides Fluorite CaF2, halite NaCl, calomel FlgCl... 

Halite (NaClk sylvite (KC.I). gehlenite (CaiALSiO/). anhydrite CaS04 Halite (NaCl)... 

Chlorine occurs mainly in seawater, in which chloride is the most abundant anion (19350 mg kg-1), and as rock salt (halite, NaCl) in evaporites. Elemental chlorine is important in sterilization of water supplies and production of chlorinated plastics such as polyvinyl chloride (PVC), but some chlorine compounds used extensively in the past, such as the insecticide... 

MX) types halite (NaCl), cesium chloride (CsCl), zinc blende (ZnS), and wurtzite (also ZnS) ... 

Chloride. Sodium chloride, common salt, rock salt, halite, NaCl, white solid, soluble, mp 804°C. See also Sodium Chloride. 

Many simple minerals, especially simple salts like halite, NaCl, sulfides, sulfosalts and oxides, have structures based upon cubic or hexagonal closest-packed arrays of either cations or anions. Coordination geometries of metal ions in many of these kinds of minerals are thus confined to more or less regular octahedra and tetrahedra. The occupancy of the two types of sites is dictated by the stoichiometry of the mineral, the radius of the ions involved and their preferred coordination geometries. Coordination of cations in mineral species in terms of bonding and crystal field effects has been extensively reviewed.16-21 Comprehensive lists of ionic radii relevant to cation coordination geometries in minerals have also been compiled.16,21... 

Ilia Simple halides halite NaCl, fluorite CaF2, chlorargyrite AgCl... 

Salt deposits or evaporites precipitate from evaporating seawater that becomes trapped in semi-isolated marine basins. Salty desert lakes, such as Great Salt Lake, Utah, USA, or those in Death Valley, California, USA, are also sites of evaporite deposition. Common salt minerals include halite (NaCl), sylvite (KC1),... 

NaCl —45 to 25 6.2 NaCl (halite), NaCl-2H20 (hydrohalite) Spencer et al. 1990... 

The ensuing suite of minerals that theoretically precipitate are, however, different for these two scenarios. For example, drying by evaporation leads to precipitation of predominantly halite (NaCl), while freezing leads to predominantly hydrohalite (NaCl-2H20) (Fig. 5.14a-b). If states of mineral hydration are preserved in ocean or lacustrine deposits on Mars, then these records could provide valuable clues to the environmental history of Mars during the drying process. 

Halite (NaCl) can be selectively floated using n-alkyl carboxylates (collector), heavy metal ions (activator), and a non polar oil (additional collector). This yields a concentrated dispersion of the potash. Alternatively, the potash can be selectively floated from a saturated brine solution, using n-alkyl amine as the collectors, leaving the other salts behind. The flotation steps may involve a sequence of rougher, cleaner, and re-deaner stages. Either way the collected potash would be centrifuge de watered, dried, then sized by screening. The final potassium concentrate would probably be at least about 60%,... 

Sufficient Na+ is now subtracted to remove all the Ch This step accounts for Cl- present in rocks as halite (NaCl), as NaCl in fluid inclusions, and as NaCl in concentrated aqueous films surrounding mineral grains in rocks. The remainder is ... 

F and Cl are moderately abundant elements, principal sources being fluorite CaF2 and halite NaCl, from which the very electronegative elements are obtained by electrolysis. Bromine is mainly obtained by oxidation of Br- found in salt water iodine occurs as iodates such as Ca(I03)2. Astatine is radioactive and only minute amounts are found in nature. Chlorine is used... 

K2NiF4-related structures, also called Ruddleston-Popper phases, are built of slabs of perovskite structure cut parallel to the (idealized) perovskite 100 planes united by way of lamellae of halite (NaCl) structure. The series formula for these compounds is where A is a large cation,... 

Chlorine Yellow-green gas 0.14 -101 -34 Rock salt (NaCl), halite (NaCl), sylvite (KC1) Electrolysis of aqueous NaCl... 

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