Glauber

Galena, see Eead sulfite Glauber s salt, see Sodium sulfate 10-water Goethite, see Iron(II) hydroxide oxide Goslarite, see Zinc sulfate 7-water Graham s salt, see Sodium phosphate(l —) Graphite, see Carbon... 

In the days of alchemy and the phlogiston theory, no system of nomenclature that would be considered logical ia the 1990s was possible. Names were not based on composition, but on historical association, eg, Glauber s salt for sodium sulfate decahydrate and Epsom salt for magnesium sulfate physical characteristics, eg, spirit of wiae for ethanol, oil of vitriol for sulfuric acid, butter of antimony for antimony trichloride, Hver of sulfur for potassium sulfide, and cream of tartar for potassium hydrogen tartrate or physiological behavior, eg, caustic soda for sodium hydroxide. Some of these common or trivial names persist, especially ia the nonchemical Hterature. Such names were a necessity at the time they were iatroduced because the concept of molecular stmcture had not been developed, and even elemental composition was incomplete or iadeterminate for many substances. 

Ammonium nitrate [6484-S2-2J, NH NO, formula wt 80.04, is the most commercially important ammonium compound both Hi terms of production volume and usage. It is the principal component of most iadustrial explosives and nonmilitary blasting compositions however, it is used primarily as a nitrogen fertilizer. Ammonium nitrate does not occur Hi nature because it is very soluble. It was first described Hi 1659 by the German scientist Glauber, who prepared it by reaction of ammonium carbonate and nitric acid. He called it nitrium flammans because its yeUow flame (from traces of sodium) was... 

Fig. 1. Solubility system of (—) Na2S04-H20 where R and M refer to rhombic and monoclinic Na2S04, respectively, ia H2O and represent Glauber s salt and sodium sulfate hemihydrate, Na2S04-7H20, respectively, at saturation ia H2O and (—) Na2S04-NaCl-H2 0 where and G represent the rhombic form and Glauber s salt, both saturated with NaCl. The dashed line represents a metastable form.

Sodium sulfate crystallised from solution has an attraction for iron and iron compounds and for various organics. Glauber s salt does not show this attraction and ia fact rejects most impurities. Thus higher quaUty Na2S04 is made from Glauber s salt. 

Nearly all manufacturers of sodium sulfate use Glauber s salt ia an iatermediate process step. Glauber s salt is then converted to anhydrous sodium sulfate. In 1990, there were only three significant producers of natural sodium sulfate O ark-Mahoning (Texas), North American Chemical (California), and Great Salt Lake Minerals (Utah). 

In Texas, subterranean sulfate brines are pumped to the surface where the brines are first saturated with NaCl before they are cooled by mechanical refrigeration to form Glauber s salt (7,8). This salt is then separated from its mother Hquor, melted, and dehydrated with mechanical vapor recompression evaporators (9). 

Processing at Sead.es Lake, California, by North American Chemical is similar to that of Texas brines. Brine is cooled to 16°C to remove borax crystals, then cooled to 4°C which precipitates Glauber s salt. This salt is then separated from its mother Hquor, melted in multi-effect vacuum crystallizers to form anhydrous sodium sulfate, and dried. Both processes produce crystals that are 99.3—99.7% pure (9). 

At Great Salt Lake Minerals Corporation (Utah), solar-evaporated brines are winter-chilled to —3° C in solar ponds. At this low temperature, a relatively pure Glauber s salt precipitates. Ponds are drained and the salt is loaded into tmcks and hauled to a processing plant. At the plant, Glauber s salt is dissolved in hot water. The resulting Hquor is filtered to remove insolubles. The filtrate is then combined with soHd-phase sodium chloride, which precipitates anhydrous sodium sulfate of 99.5—99.7% purity. Great Salt Lake Minerals Corporation discontinued sodium sulfate production in 1993 when it transferred production and sales to North American Chemical Corporation (Trona, California). 

Figure 2 shows a general process flow diagram for almost all production of natural sodium sulfate. Glauber s salt can be converted to anhydrous sodium sulfate by simply drying it in rotary kilns. Direct drying forms a fine, undesirable powder, and any impurities in the Glauber s salt become part of the final product. This process is not used in the United States but is used in other countries. 

Recovery Process. The process for making sodium sulfate [7757-82-6] is different at each faciUty extracting it from brine. One step common to all facihties is a cooling step to form Glauber s salt followed by a purification and recrystallization step to form anhydrous sodium sulfate. 

In Texas, brine is pumped from underground deposits. Sodium chlodde is added to bring the brine near saturation. This solution is then chilled to —8°C to crystallize Glauber s salt (71). Anhydrous Na2S04 is recovered by artificially evaporating the Hquor formed by remelting the Glauber s salt. 

At Seades Lake, sodium sulfate is recovered as one of three coproducts in a senes of complex operations where soda ash and borax are also recovered from the brine. Anhydrous sodium sulfate is recovered by artificially evaporating the water from Glauber s salt. 

Mi. (B) N32S04 PRODUCTION FROM GLAUBERS SALT. MELTING TANK INCLUDED... 

Concentrated HCl prepared by J.L. Glauber (by heating hydrated ZnCU and sand)... 

Glaubersalz, n. Glauber s salt (sodium sulfate decahydrate). 

It should be realized that unlike the study of equilibrium thermodynamics for which a model is often mapped onto Ising system, elementary mechanism of atomic motion plays a deterministic role in the kinetic study. In an actual alloy system, diffusion of an atomic species is mainly driven by vacancy mechanism. The incorporation of the vacancy mechanism into PPM formalism, however, is not readily achieved, since the abundant freedom of microscopic path of atomic movement demands intractable number of variational parameters. The present study is, therefore, limited to a simple spin kinetics, known as Glauber dynamics [14] for which flipping events at fixed lattice points drive the phase transition. Hence, the present study for a spin system is regarded as a precursor to an alloy kinetics. The limitation of the model is critically examined and pointed out in the subsequent sections. 

It is important to realize that detailed balance does not uniquely prescribe the set of transition probabilities many different choices are possible. One common choice, due to Glauber [glaub63], is to let... 

The equation shows that the solubility curve must be continuous all breaks indicate that the solid phase in contact with the saturated solution has altered in character, and we really have to do with two distinct solubility curves meeting at an angle. This occurs, for example, with Glauber s salt at 32° 6, for this is the transition temperature for the reaction... 

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