World calcium chloride

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. 

Calcium metal was produced in 1855 by electrolysis of a mixture of calcium, strontium, and ammonium chlorides, but the product was highly contaminated with chlorides (1). By 1904 fairly large quantities of calcium were obtained by the electrolysis of molten calcium chloride held at a temperature above the melting point of the salt but below the melting point of calcium metal. An iron cathode just touched the surface of the bath and was raised slowly as the relatively chloride-free calcium solidified on the end. This process became the basis for commercial production of calcium metal until World War II. 

A former commercially important source of calcium chloride was as a by-product of the Solvay process used to produce soda ash (28). Because of environmental concerns and high energy costs, the Solvay process has been discontinued ia the United States though it is stiU used extensively elsewhere ia the world (see Calcium compounds). 

Ethylene oxide has been produced commercially by two basic routes the ethylene chlorohydrin and direct oxidation processes. The chlorohydrin process was first iatroduced dufing World War I ia Germany by Badische Anilin-und Soda-Eabfik (BASE) and others (95). The process iavolves the reaction of ethylene with hypochlorous acid followed by dehydrochlofination of the resulting chlorohydrin with lime to produce ethylene oxide and calcium chloride. Union Carbide Corp. was the first to commercialize this process ia the United States ia 1925. The chlorohydrin process is not economically competitive, and was quickly replaced by the direct oxidation process as the dominant technology. At the present time, all the ethylene oxide production ia the world is achieved by the direct oxidation process. 

About 95% of the sodium carbonate used in the U.S. is mined, primarily in Wyoming. The ore is known as trona and needs only to be heated to produce commercial soda ash. Elsewhere in the world it is made by the Solvay process, which uses limestone and salt as raw materials. Calcium chloride is a byproduct of the Solvay process. 

Sodium chloride is found in salt beds, salt brines, and sea water throughout the world, and it is also mined is some locations. Consequently, sodium chloride is the source of numerous other sodium compounds. A large portion of the sodium chloride utilized is consumed in the production of sodium hydroxide (Eq. (11.23)). The production of sodium metal involves the electrolysis of the molten chloride, usually in the form of a eutectic mixture with calcium chloride. Sodium carbonate is an important material that is used in many ways such as making glass. It was formerly produced from NaCl by means of the Solvay process, in which the overall reaction is... 

Calcium is the fifth most abundant element found in the Earths crust. It is not found as a free element, but as calcium compounds (mostly salts and oxides), which are found on all landmasses of the world as limestone, marble, and chalk. Calcium, particularly as the compound calcium chloride (CaCl ), is found in the oceans to the extent of 0.15%. 

Bensted, J. 1977. Chloroaluminates and the role of calcium chloride in accelerated hardening of Portland cement. World Cement Technology, 8, 171-175. 

PO was manufactured by the chlorohydrin route first during World War I in Germany by BASF and others. This route (below) involves reaction of propylene with hypochlorous acid followed by treatment of the resulting propylene chlorohydrin with a base such as caustic or lime. The products of the second reaction are PO and sodium or calcium chloride (Fig. 10.22). 

A shift to the processing of substantial alternate natural mineral sources of sodium carbonate in the U.S. has eliminated the calcium chloride disposal problems of the Solvay process for sodium carbonate production. Coupling this advantage to the much lower capital cost of a natural sodium carbonate plant has contributed to the shift away from synthetic sodium carbonate in the U.S. [13] (Table 7.3). Kenya is the only other country reported to be recovering natural sodium carbonate and was operating at 260,000 metric toimes in 2001 [19]. China, the second largest producer, and all other world producers still rely heavily on the ammonia-soda process [17, 24] (Table 7.4). 

I.2. Propylene Chlorohydrin. Propylene chlorohydrin is one of the most important intermediates used in the production of PO, which is a raw material for producing propylene glycols and urethane polyether polyols. The United States and Western Europe are the largest producers of propylene chlorohydrin, accounting for 74% of the world s production. The main environmental issues relate to the chlorinated waste generated in the process and the disposal of the byproduct calcium chloride sludge. The formation of... 

Before World War II calcium metal was made by electrolysis of fused calcium chloride at 800°C. A metal with 98% calcium was obtained. In a modem method, a variant of the Pidgeon magnesium process, briquettes of Hme and aluminum powder are heated in evacuated retorts at 1150°C. Calcium metal with a purity of 99% is formed and evaporated. The calcium vapor is condensed in the water-cooled ends of the retorts. By repeated vacuum distillation the purity can be improved to 99.9%. The metal is stored and transported in steel barrels filled with argon. 

The standard hard water recommended by WHO, and used in labs around the world, is made from a combination of calcium and magnesium salts in a set ratio. The hardness of this water is 342 ppm, when determined as calcium carbonate. The recipe for preparing this water is to dissolve 0.304 grams anhydrous calcium chloride and 0.139 grams magnesium chloride hexahydrate in distilled water and dilute to one liter. A typical evaluation program will use 342 ppm water as the standard, with other waters ranging from 34 ppm to 1000 ppm hardness added as demanded by end-use requirements. 

One of the most unusual of the world s calcium chloride lakes is Lake Vanda and the nearby Don Juan Pond in Antarctica. The lake is covered with ice, there is nearly fresh water under the ice, and below that a stratified strong calcium chloride... 

The General Chemicals Group in Manistee and the Wilkinson Co. in Mayville also produced calcium chloride from Michigan brines in 2002. However, in late 2002 the General Chemical Group announced that they had closed their Manistee plant with a capacity of 450,0(X) st equivalent fiake/yr. None of the world s other... 

Uses. AEyl chloride is industrially the most important aHyl compound among all the aHyl compounds (see Chlorocarbons and CHLOROHYDROCARBONS, ALLYL CHLORIDE). It is used mosdy as an intermediate compound for producing epichlorohydrin, which is consumed as a raw material for epoxy resins (qv). World production of AC is approximately 700,000 tons per year, the same as that of epichlorohydrin. Epichlorohydrin is produced in two steps reaction of AC with an aqueous chlorine solution to yield dichloropropanol (mixture of 1,3-dichloropropanol and 2,3-dichloropropanol) by chlorohydrination, and then saponification with a calcium hydroxide slurry to yield epichlorohydrin. 

Great Salt Lake, Utah, is the largest terminal lake in the United States. From its brine, salt, elemental magnesium, magnesium chloride, sodium sulfate, and potassium sulfate ate produced. Other well-known terminal lakes ate Qinghai Lake in China, Tu2 Golu in Turkey, the Caspian Sea and Atal skoje in the states of the former Soviet Union, and Urmia in Iran. There ate thousands of small terminal lakes spread across most countries of the world. Most of these lakes contain sodium chloride, but many contain ions of magnesium, calcium, potassium, boron, lithium, sulfates, carbonates, and nitrates. 

The main metals in brines throughout the world are sodium, magnesium, calcium, and potassium. Other metals, such as lithium and boron, are found in lesser amounts. The main nonmetals ate chloride, sulfate, and carbonate, with nitrate occurring in a few isolated areas. A significant fraction of sodium nitrate and potassium nitrate comes from these isolated deposits. Other nonmetals produced from brine ate bromine and iodine. 

Since World War 11, the U.S. space program and the military have used small amounts of insoluble chromates, largely barium and calcium chromates, as activators and depolarizers in fused-salt batteries (214,244). The National Aeronautics and Space Administration (NASA) has also used chromium (111) chloride as an electrolyte for redox energy storage cells (245). 

Reaction of coke with calcium oxide gives calcium carbide, which on treatment with water produces acetylene. This was for many years an important starting point for the production of acrylonitrile, vinyl chloride, vinyl acetate and other vinyl monomers. Furthermore, during World War II, Reppe developed routes for many other monomers although these were not viable under normal economic conditions. 

Clinical chemistry, particularly the determination of the biologically relevant electrolytes in physiological fluids, remains the key area of ISEs application [15], as billions of routine measurements with ISEs are performed each year all over the world [16], The concentration ranges for the most important physiological ions detectable in blood fluids with polymeric ISEs are shown in Table 4.1. Sensors for pH and for ionized calcium, potassium and sodium are approved by the International Federation of Clinical Chemistry (IFCC) and implemented into commercially available clinical analyzers [17], Moreover, magnesium, lithium, and chloride ions are also widely detected by corresponding ISEs in blood liquids, urine, hemodialysis solutions, and elsewhere. Sensors for the determination of physiologically relevant polyions (heparin and protamine), dissolved carbon dioxide, phosphates, and other blood analytes, intensively studied over the years, are on their way to replace less reliable and/or awkward analytical procedures for blood analysis (see below). 

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