Electric drying

The product is stable, free-flowing crystals. As a fertilizer, (NR SQ has the advantage of adding sulfur to the soil as well as nitrogen. By weight, the compound contains 21% N and 24% S. Ammonium sulfate also is used in electric dry cell batteries, as a soldering liquid, as a fire retardant for fabrics and other products, and as a source of certain ammonium chemicals. See also Fertilizer and Nitrogen. 

Batteries, Electric, Dry are described in Kirk Othmer 2(1948),324-340(7refs)... 

Very pure CuO (15 g.) is dissolved in a clear, carbonate-free solution of 500 g. of NaOH in 330 ml. of HsO (brief refluxing). The dark-blue solution is cooled to 110 C and carefully diluted by adding 140 ml. of H3O through the reflux condenser (use a funnel). The small quantity of unreacted CuO is then filtered off, collecting the filtrate in a preheated Erlenmeyer flask of refined silver. The Erlenmeyer flask is protected by a Peligot tube (filled with 50% KOH) and kept in an electric drying oven for six days at TO C to allow the filtrate to crystallize. The mixture is then filtered the crystals are washed with some 50% and 45% sodium hydroxide (once each) at room temperature and dried on a clay plate over H3SO4. Yield 13 g. 

IL Freshly precipitated, thoroughly washed FesOa aq. is added to carbonate-free 50% NaOH. An amount of NaOH equal in weight to the water contained in the FesOa paste is then added and the latter is dissolved with moderate heating (not to exceed 60 °C). The mixture, in a silver Erlenmeyer flask protected with a Peligot tube (filled with 50% KOH), is allowed to stand for several days in an electric drying oven at 70°C. In this manner, the FesOa aq. is completely converted into the nearly colorless, microcrystalline Na4[Fe(OH)7] 2 HsO, which is sparingly soluble in concentrated NaOH. 

A decomposition reaction is the opposite of a combination reaction. An example of a decomposition reaction in which a compound decomposes to form the elements in it is provided by the manufacture of carbon black. This material is a finely divided form of pure carbon, C, and is used as a filler in rubber tire manufacture and as an ingredient in the paste used to fill electrical dry cells. It is made by heating methane (natural gas) to temperatures in the range of 1260-1425°C in a special furnace, causing the following reaction to occur ... 

In this section, electrical drying methods are briefly discussed - examples of applications are discussed in Chapter 10. As an example, the industrial microwave dryer exhibits similar benefits to the domestic microwave oven - the energy is taken directly to the inside of the object(s) being heated, rather than having to be conducted from the surface of the particle or body. Microwave drying can be combined with conventional (hot air) drying to finish off the process, and a combination of... 

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