Magnesium chloride, recovery

In addition to freshwater, seawater is also a source for sodium, magnesium, chlorides, iodine, bromine, and magnesium metal (see Sodium coLD>ouNDS Magnesium coLD>ouNDS Iodine Bromine Magnesiumand magnesium alloys). Many other elements are certain to be economically obtained from the ocean as technology for the recovery improves. 

The ionic species of the mobile phase will also affect the separation. This is shown in Table 4.3 by the difference in resolution values for magnesium chloride buffer compared to sodium sulfate buffer. In addition, calibration curves for proteins in potassium phosphate buffers are shallower than those generated in sodium phosphate buffers. The slope of the curve in Sorenson buffer (containing both Na and ) is midway between the slopes generated with either cation alone (1). Table 4.4 illustrates the impact of different buffer conditions on mass recovery for six sample proteins. In this case, the mass recovery of proteins (1,4) is higher with sodium or potassium phosphate buffers (pH 6.9) than with Tris-HCl buffers (pH 7.8). 

During improved oil-recovery processes, waterflooding of the oil is applied. The entrained water forms a water-in-oil emulsion with the oil. In addition, salts such as sodium chloride, calcium chloride, and magnesium chloride may be dissolved in the emulsified water. 

The bittern (spent brine) from solar salt production contains 300 00 g/L dissolved solids relatively enriched in the less concentrated salt impurities. This may be either discarded or further worked to recover other elements of value. Brine from the Great Salt Lake, for instance, is processed for magnesium chloride hexahydrate recovery [10], which occurs at a density of 1.26g/cm. This is later converted to metallic magnesium [12]. The Dead Sea brines are processed primarily for potassium chloride (potash), but are also worked for sodium and magnesium chlorides and derived products such as bromine and hydrochloric acid [16] (Sections 6.2.2 and 8.8). 

Brine-disposal problems may be avoided by proposed modifications to the Solvay process, which employ magnesium hydroxide for ammonia recovery [17]. The magnesium chloride formed could be recycled and hydrogen chloride obtained as a coproduct by contacting the magnesium chloride with superheated steam (Eqs. 7.18 and 7.19). However, this process remains unproven. 

C. Hanson and S. L. N. Murthy, Recovery of magnesium chloride from sea water concentrates. Proceedings of Int. Solv. Extr. Conf., 1974, Vol. 1, pp. 779-790. 

In most production wells, chloride salts are found either dissolved in water that is emulsified in crude oU or as suspended solids. Salts also originate from brines injected for secondary recovery or from seawater ballast in marine tankers. Typically, the salts in crude oils consist of 75% sodium chloride, 15% magnesium chloride, and 10% calcium chloride. When crude oils are charged to crude distillation units and heated to temperatures above approximately 120 °C, hydrogen chloride is evolved from magnesium and calcium chloride, whUe sodium chloride is essentiaUy stable up to roughly 750 °C. 

Recovery from Brines. Natural lithium brines are predominately chloride brines varying widely in composition. The economical recovery of lithium from such sources depends not only on the lithium content but on the concentration of interfering ions, especially calcium and magnesium. If the magnesium content is low, its removal by lime precipitation is feasible. Location and avadabiHty of solar evaporation (qv) are also important factors. 

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Chemicals from brine, 5 784-803 calcium chloride, 5 793-795 iodine, 5 795—796 lithium, 5 796-797 magnesium compounds, 5 797-798 minerals from brine, 5 790-793 potassium compounds, 5 798-799 recovery process, 5 786-790 sodium carbonate, 5 799-800 sodium chloride, 5 800-801 sodium sulfate, 5 801-802 Chemicals Guideline, integrated,... 

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