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Ocean magnesium

AH metals come originally from natural deposits present in the earth s cmst. These ore deposits result from a geological concentration process, and consist mainly of metallic oxides and sulfides from which metals can be extracted. Seawater and brines are another natural source of metals, eg, magnesium (see Chemicals frombrine Magnesium and magnesium alloys Ocean raw materials). Metal extracted from a natural source is called primary metal. [Pg.162]

Dissolved Minerals. The most significant source of minerals for sustainable recovery may be ocean waters which contain nearly all the known elements in some degree of solution. Production of dissolved minerals from seawater is limited to fresh water, magnesium, magnesium compounds (qv), salt, bromine, and heavy water, ie, deuterium oxide. Considerable development of techniques for recovery of copper, gold, and uranium by solution or bacterial methods has been carried out in several countries for appHcation onshore. These methods are expected to be fully transferable to the marine environment (5). The potential for extraction of dissolved materials from naturally enriched sources, such as hydrothermal vents, may be high. [Pg.288]

Chlorine. Chlorine, the material used to make PVC, is the 20th most common element on earth, found virtually everywhere, in rocks, oceans, plants, animals, and human bodies. It is also essential to human life. Eree chlorine is produced geothermally within the earth, and occasionally finds its way to the earth s surface in its elemental state. More usually, however, it reacts with water vapor to form hydrochloric acid. Hydrochloric acid reacts quickly with other elements and compounds, forming stable compounds (usually chloride) such as sodium chloride (common salt), magnesium chloride, and potassium chloride, all found in large quantities in seawater. [Pg.508]

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. [Pg.240]

Besides the oceans, there are vast reserves of magnesium chloride in the Dead Sea Qaidam Basin, China and many salars of South America. [Pg.411]

An idea of the.diktributibh bf galvanic corrosion in the atmosphere is prp vided by the location of the corrosion of magnesium exposed in intimate contact with steel in the assembly shown in Fig. 19.28 after exposure in the salt atmosphere 25 m from the ocean at Kure Beach, North Carolina, for 9 years. Except where ledges or crevices may serve to trap unusual amounts of electrolyte, it may be assumed that, even with the most incompatible metals, simple galvanic effects will not extend more than about 4-5 mm from the line of contact of the metals in the couple. [Pg.1070]

As can be seen in Fig. 2-1 (abundance of elements), hydrogen and oxygen (along with carbon, magnesium, silicon, sulfur, and iron) are particularly abundant in the solar system, probably because the common isotopic forms of the latter six elements have nuclear masses that are multiples of the helium (He) nucleus. Oxygen is present in the Earth s crust in an abundance that exceeds the amount required to form oxides of silicon, sulfur, and iron in the crust the excess oxygen occurs mostly as the volatiles CO2 and H2O. The CO2 now resides primarily in carbonate rocks whereas the H2O is almost all in the oceans. [Pg.112]

There is some debate about what controls the magnesium concentration in seawater. The main input is rivers. The main removal is by hydrothermal processes (the concentration of Mg in hot vent solutions is essentially zero). First, calculate the residence time of water in the ocean due to (1) river input and (2) hydro-thermal circulation. Second, calculate the residence time of magnesium in seawater with respect to these two processes. Third, draw a sketch to show this box model calculation schematically. You can assume that uncertainties in river input and hydrothermal circulation are 5% and 10%, respectively. What does this tell you about controls on the magnesium concentration Do these calculations support the input/removal balance proposed above Do any questions come to mind Volume of ocean = 1.4 x 10 L River input = 3.2 x lO L/yr Hydrothermal circulation = 1.0 x 10 L/yr Mg concentration in river water = 1.7 X 10 M Mg concentration in seawater = 0.053 M. [Pg.273]

Rainwater Groundwater, lakes, rivers, seas, and oceans Carbon dioxide, nitrogen, oxygen, dust Sand (silica) and soil particles chlorides, bicarbonates, and sulfates, mainly of calcium, sodium, magnesium, and iron ions organic Air pollutants Rocks and soil, microorganisms, plant and animal... [Pg.440]

Handschuh and Orgel (1973) studied the mineral struvite. It can be precipitated from ocean water in the presence of phosphate if the concentration of NH ions in the water is greater than 0.01 M. If struvite is heated with urea, magnesium pyrophosphate is obtained in a yield of about 20% after 10 days at 338 K if nucleosides are added to the reaction mixture described above, nucleoside diphosphates such as uridine-5 -diphosphate and diuridine-5 -diphosphate are formed in good yields. [Pg.117]

Wiggins et al. [456] used neutrons from the thermal column of a 10 kW pool-type research reactor and from a 120 pg Cf source to study the prompt photon emission resulting from neutron capture in magnesium nodules (ter-romanganese oxides) from the ocean floor. Spectra were recorded with a Ce(Ii) detector and a 1024-channel analyser. Complex spectra were obtained by irradiation of seawater, but it was possible to detect and estimate manganese in nodules in a simulated marine environment by means of the peaks at 7.00, 6.55, 6.22, and 6.04 pV. [Pg.197]

Raisbeck et al. have reported on the application of the Grenoble cyclotron for the measurement of 10Be in artifically enriched samples [9]. Later experiments have measured 10Be in melted arctic glacier ice cores [10], marine sediments [32] and ocean surface layers [33]. The Yale group, Turekian et al., [11] have measured the 10Be content in magnesium nodules and demonstrated that these nodules accrete at the rate of approximately 4.5 mm/106 years. [Pg.69]

Hydrothermal vents are another source of water entering the ocean. These vents are submarine hot-water geysers that are part of seafloor spreading centers. The hydrothermal fluids contain some major ions, such as magnesium and sulfete, in significantly different ratios than foimd in seawater. The importance of hydrothermal venting in determining the chemical composition of seawater is described in Chapters 19 and 21. [Pg.63]

Most cation exchange occurs in estuaries and the coastal ocean due to the large difference in cation concentrations between river and seawater. As riverborne clay minerals enter seawater, exchangeable potassium and calcium are displaced by sodium and magnesium because the Na /K and Mg /Ca ratios are higher in seawater than in river water. Trace metals are similarly displaced. [Pg.362]

On the early Earth, ions were mobilized from volcanic rocks by chemical weathering. Rivers and hydrothermal emissions transported these chemicals into the ocean, making seawater salty. These salts are now recycled within the crustal-ocean-atmosphere fectory via incorporation into sediments followed by deep burial, metamorphosis into sedimentary rock, uplift, and weathering. The last process remobilizes the salts, enabling their redelivery to the ocean via river runoff and aeolian transport. In the case of sodium and chlorine, evaporites are the single most important sedimentary sink. This sedimentary rock is also a significant sink for magnesium, sulfate, potassium, and calcium. [Pg.423]

The clay minerals carried by rivers into the ocean represent a net annual addition of 5.2 X 10 mEq of cation exchange capacity. Most of these exchange sites are occupied by calcivun. Within a few weeks to months following introduction into seawater, sodium, potassium, and magnesium displace most of the calcium. As shown in Table 21.7, this uptake removes a significant fraction of the river input of sodium, magnesium, and potassium. [Pg.545]


See other pages where Ocean magnesium is mentioned: [Pg.571]    [Pg.529]    [Pg.571]    [Pg.529]    [Pg.801]    [Pg.32]    [Pg.220]    [Pg.313]    [Pg.315]    [Pg.318]    [Pg.338]    [Pg.343]    [Pg.120]    [Pg.406]    [Pg.512]    [Pg.2518]    [Pg.18]    [Pg.555]    [Pg.32]    [Pg.302]    [Pg.262]    [Pg.125]    [Pg.349]    [Pg.197]    [Pg.499]    [Pg.501]    [Pg.535]    [Pg.543]    [Pg.543]    [Pg.545]    [Pg.275]    [Pg.512]    [Pg.277]    [Pg.316]    [Pg.6]    [Pg.459]   
See also in sourсe #XX -- [ Pg.72 ]




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