Oceanic salts sodium chloride

Removal of salts from the crude is important to avoid corrosion and plugging of the overhead system. Any plugging is normally caused by ammonium chloride. Salt wateV in crude is usually similar to ocean water. Sodium chloride, which is quite soluble in hot water, is easily removed. Magnesium chloride,... 

Common salt, sodium chloride, occurs widely in nature, both as deposits left by ancient seas and in the ocean, where its average concentration is 2.6%. 

The need for a cheap and abundant source of sodium carbonate was already felt in prerevolutionary France, where sodium carbonate had to be imported or made from wood ash. The French Academy of Sciences offered a considerable prize to anyone who came up with a method of preparing sodium carbonate from common salt, sodium chloride. France had, of course, oceans of salt. 

Retention times for most soluble salts are extremely long. The most abundant salt in oceans is sodium chloride. Oceans of Earth have never been saturated with this salt and it has never turned over once since Earth s beginning. This does not mean that local deposits have not formed in large quantities and that large quantities have not been removed and replaced. It merely means that oceans have not become saturated with respect to sodium chloride, potassium chloride, ammonium chloride, sodium nitrate, and other soluble salts as they have with calcium phosphates. ... 

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. 

Chlorine. Nearly all chlorine compounds are readily soluble in water. As a result, the major reservoir for this element in Figure 1 is the ocean (5). Chloride, as noted earHer, is naturally present at low levels in rain and snow, especially over and near the oceans. Widespread increases in chloride concentration in mnoff in much of the United States can be attributed to the extensive use of sodium chloride and calcium chloride for deicing of streets and highways. Ref. 19 points out the importance of the increased use of deicing salt as a cause of increased chloride concentrations in streams of the northeastern United States and the role of this factor in the chloride trends in Lake Ontario. Increases in chloride concentration also can occur as a result of disposal of sewage, oil field brines, and various kinds of industrial waste. Thus, chloride concentration trends also can be considered as an index of the alternation of streamwater chemistry by human development in the industrialized sections of the world. Although chlorine is an essential element for animal nutrition, it is of less importance for other life forms. 

Occurrence. About half of all the sodium chloride [7647-14-5J produced in the wodd is from brine. Approximately one hundred million tons pet year are produced from brines of the ocean, terminal lakes, subterranean aquifers, and solution mining (14). Sodium is found in large quantities in most areas of the world. Its quantity is so large that prices in some locations are only a few dollars per ton. Many areas have millions of tons but prices are so low that it is not economical to mine or process the salt. The largest exposed sodium chloride bed is at the Salat de Uyuni, Bohvia, but Bohvia is landlocked and very htde of the salt can be processed and sold at a profit. 

Ocean sea water is roughly equivalent in strength to a 3 j % w/v solution of sodium chloride, but it has a much more complex composition, embodying a number of major constituents, and traces at least of almost all naturally occurring elements. For convenience, however, the concentration of salts in any sample of sea water is expressed in terms of the chloride content, either as chlorinity or as salinity. Both these units are again subject to arbitrary definition and do not conform simply to the chemical composition. 

Usually we think of solutions as liquids, and aqueous solutions are the most common liquid solutions in eveiyday life. Blood, sweat, and tears all are aqueous solutions. So are the beverages that we drink. The oceans are aqueous solutions of sodium chloride and other mineral salts. Even the fresh waters of streams and lakes are aqueous solutions containing salts and organic solutes. Most of this chapter discusses aqueous solutions. 

Similar elements also occur in the same natural environment. For instance, the halogens are markedly concentrated in seawater. (The major salt in ocean brines is sodium chloride.) The other halogens are extracted from seawater that has been further concentrated—bromine from salt beds formed by evaporation and iodine from kelp, which grows in oceans. 

Sodium chloride is widely distributed in nature. Oceans are the vast source of sodium chloride. It occurs in seawater at an average concentration of 2.68 wt%. It also occurs in many inland saline waters and in salt deposits in sedimentary rocks, as the mineral hahte. 

Sodium chloride (NaCl) is the most common sodium salt. — it is the chemical that makes ocean water salty. Plants growing in the ocean take up so much of the sodium that people along the seacoasts of the world used to burn dried seaweed to secure soda ash (sodium carbonate, Na,CO,). Inland plants, on the other hand, pick up potassium from the soil. Inland people boiled out wood ashes in large pots to get potash (potassium carbonate, K2COs). 

Sodium compounds are important largely because they are inexpensive and soluble in water. Sodium chloride is readily mined as rock salt, which is a deposit of sodium chloride left as ancient oceans evaporated and it is also obtained from the evaporation of brine from present-day seas and salt lakes (Fig. 14.19). Sodium chloride is used in large quantities in the electrolytic production of chlorine and sodium hydroxide from brine. 

Seawater is unfit for drinking or agriculture because each kilogram contains about 35 g of dissolved salts. The most abundant salt in seawater is sodium chloride, but more than 60 different elements are present in small amounts. Table 14.3 lists the ions that account for more than 99% of the mass of the dissolved salts. Although the oceans represent an almost unlimited source of chemicals, ion concentrations are so low that recovery costs are high. Only three substances are obtained from seawater commercially sodium chloride, magnesium, and bromine. 

Seawater contains about 3.5% salts, in which the content of sodium chloride is about 80%. The concentration of dissolved salts as well as temperature and pressure influence the physical properties of seawater. The total salt concentration is usually called salinity . Salinity is generally measured by the electrical conductivity or determination of chloride content. At present, salinity(S) is defined as S = 1.80655 Cl (Cl is the concentration of chloride in seawater) [5]. Dissolved oxygen and silica are usually measured as additional parameters to characterize seawater. The concentrations of nitrogen and phosphorus are the indices of nutrients and measure the fertility and production of the oceans. 

For example, a 3 per cent, solution of common salt at 10° C. is much more corrosive than tap water at the same temperature but as the temperature rises the relative corrosivity falls, so much so that at 21° C. the salt solution is the 1 ess corrosive of the two. Since sea water contains some 3 per cent, of sodium chloride, it is of interest to inquire into the effect of temperature upon its corrosive powers. The few laboratory tests that have been carried out on the subject2 indicate that at temperatures below 13° C. sea water is more corrosive than tap water, whilst at all higher temperatures it is less so. Now, in the western part of the tropical Pacific Ocean a temperature of 32° C. is sometimes attained, and in the Red Sea and Persian Gulf temperatures of 34 4° C. and 35 5° C. respectively have been registered. Such waters should therefore prove less corrosive than river waters at the same temperatures. 

Mono Lake is another closed, saline lake with a unique chemistry. It is alkaline (pH = 10), and almost three times as salty as the ocean. Its salinity is approximately 81 g/L (in 1913 it reached a record salinity of 133 g/L). Its waters contain dissolved sodium salts (as chlorides, carbonates, and sulfates) in contrast, the Great Salt Lake contains abundant chlorides but very few carbonates. Mono Lake is also rich in borate and potassium ions (among the highest concentrations ever recorded). The salinity of the first two cases is compared to that of the ocean in Table 6.6 (as weight % of dry TDS). 

Bromine is too reactive to exist as a free element in nature. Instead, it occurs in compounds, the most common of which are sodium bromide (NaBr) and potassium bromide (KBr). These compounds are found in seawater and underground salt beds. These salt beds were formed in regions where oceans once covered the land. When the oceans evaporated (dried up), salts were left behind—primarily sodium chloride (NaCl), potassium chloride (KCl), and sodium and potassium bromide. Later, movements of Earth s crust buried the salt deposits. Now they are buried miles underground. The salts are brought to the surface in much the same way that coal is mined. 

Pure sodium chloride contains 60.66% chlorine by mass, whether we obtain it from salt mines, crystallize it from waters of the oceans or inland salt seas, or synthesize it from its elements, sodium and chlorine. ... 

Ingestion is the primary route of exposure to sodium. Many foods contain sodium chloride naturally (e.g., milk, cheese, shellfish, and, to a lesser extent, meat and poultry). Nonetheless, most people add extra table salt to their food to the extent of 2000-7000 mg day In addition, all water supplies tested and nearly all carbonated beverages contain sodium. Inhalation of sodium is a minor route of exposure except in some industrial environments. Sodium in the air comes from the oceans. Dermal absorption is not normally considered an important exposure pathway. 

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