Miscellaneous Inorganic Chemicals

There are two inorganic chemicals in the top 50 that we have not yet covered potash and carbon black, which are difficult to classify under a previous category. 

The industrial term potash can be very misleading. It can refer to potassium carbonate (K2CO3), potassium hydroxide (KOH), potassium chloride (KCl), potassium sulfate (K2SO4), potassium nitrate (KNO3), or collectively to all potassium salts and to the oxide K2O. More correctly KOH is called caustic potash and KCl is called muriate of potash. Production is recorded in weight equivalents of K2O since almost all potash is used as fertilizer and this industry quotes weight percentages of K2O in its trade. 

Large deposits of sylvinite (42.7% KCl, 56.6% NaCl) near Carlsbad, New Mexico, account for 85% of the potassium products produced in the U.S. The potassium chloride can be separated by either fractional crystallization or flotation. Potassium chloride is also obtained from the brines of Searles Lake, California. All these sources give potash (97% potassium chloride) with a 60% K2O equivalent for fertilizer use. A chemical-grade product can be obtained to a purity of 99.9% potassium chloride. Almost all potash produced is potassium chloride. Potash is used mainly as fertilizer (88%) with a small amount (12%) used in chemical manufacture. 

A small amount of potassium sulfate is isolated from natural deposits. Potassium nitrate is made by two synthetic processes. 

Potassium hydroxide is made by electrolysis of potassium chloride solutions in cells that are exactly analogous to sodium hydroxide production. 

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Miscellaneous Inorganic Chemicals and Associated Air Pollution Emissions... 

Miscellaneous. Hydrochloric acid is used for the recovery of semiprecious metals from used catalysts, as a catalyst in synthesis, for catalyst regeneration (see Catalysts, regeneration), and for pH control (see Hydrogen-ION activity), regeneration of ion-exchange (qv) resins used in wastewater treatment, electric utiUties, and for neutralization of alkaline products or waste materials. In addition, hydrochloric acid is also utilized in many production processes for organic and inorganic chemicals. 

Table 6.2 shows the important applications of sodium hydroxide. Direct applications can be further broken down into pulp and paper (24%), soaps and detergents (10%), alumina (6%), petroleum (7%), textiles (5%), water treatment (5%), and miscellaneous (43%). Organic chemicals manufactured with sodium hydroxide are propylene oxide (23%), polycarbonate (5%), ethyleneamines (3%), epoxy resins (3%), and miscellaneous (66%). Inorganic chemicals manufactured are sodium and calcium hypochlorite (24%), sodium cyanide (10%), sulfur compounds (14%), and miscellaneous (52%). As you can see from the number of applications listed, and still the high percentages of miscellaneous uses, sodium hydroxide has a very diverse use profile. It is the chief industrial alkali. 

The various types of compounds which have been purified with peroxygens and which will be discussed here are petroleum products, miscellaneous organic chemicals, surfactants, natural oils, waxes and gums, natural sugars and starches, synthetic polymers, inorganic acids and salts, clays, talc and minerals. 

Figure 10.3 Market outlets for caustic soda, a, vinyl chloride b, solvents c, propylene oxide d, chloromethanes e, inorganic chemicals f, paper/pulp g, miscellaneous.

The estimated consumption of sulfuric acid in 1996 by the industrial sector in the United States is shown in Figure 35.1. In Canada, while fertilizer consumption is not as prominent, consumption of sulfuric acid follows a similar pattern to that in the United States fertilizers—68% mining—5.8% miscellaneous—10.6% inorganics—5.1% others, including petroleum refining and products, synthetic rubber and plastics, pulp mills and other paper products, and industrial organic chemicals—10.5% (CIS, 1997). Sulfuric acid consumption is very stable and should continue to be so. 

In the Landolt-Bdmstein data collection, ferroelectric and antiferroelectric substances are classified into 72 families according to their chemical composition and their crystallographic structure. Some substances which are in fact neither ferroelectric nor antiferroelectric but which are important in relation to ferroelectricity or anti-ferroelectricity, for instance as an end material of a solid solution, are also included in these families as related substances. This subsection surveys these 72 families of ferroelectrics presented in Landolt-Bornstein Vol. III/36 (LB III/36). Nineteen of these families concern oxides [5.1,2], 30 of them concern inorganic crystals other than oxides [5.3], and 23 of them concern organic crystals, liquid crystals, and polymers [5.4]. Table 4.5-1 lists these families and gives some information about each family. Substances classified in LB 111/36 as miscellaneous crystals (outside the families) are not included. 

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