Nitric Acid processes

In both the sulfuric and nitric acid processes, the dorn metal must be in shot form prior to treatment to secure a reasonably rapid reaction. A number of steps also may be required in processing the dorne metal to remove miscellaneous impurities, particularly in treating material from copper-anode slime (31). 

Latest Nitric Acid Process Design," Nitrogen (165) (fan.—Feb. 1987). 

Figure 4.2. Flow-sheet simplified nitric acid process (Example 4.2) (1) See example...

This example illustrates how the techniques used in an operability study can be used to decide the instrumentation required for safe operation. Figure 9.5a shows the basic instrumentation and control systems required for the steady-state operation of the reactor section of the nitric acid process considered in Example 4.4. Figure 9.5b shows the... 

Electric arc nitric acid processes, 77 186 Electric arc processes, of ammonia synthesis, 77 114-115 Electric-arc vaporizer zinc oxide process, 26 613... 

HOKO nitric acid process, 77 185 Holding furnaces, 72 313 Holds (ships), corrosion protection coatings, 7 205... 

Klaproth, Martin H., 11 398 Klatte, Fritz, 25 628 Kleiner nitric acid process, 17 186 Klosterboer-Rutledge (KR) model, 19 356 Kluveromyces lactis, 12 479 genome of, 26 450t Klystrons, 23 135-136 K-matrix methods, 14 239 Kneading process, in paper recycling, 21 439 440... 

Nitric acid processes. See also Nitric acid concentration (NAC) processes alternative, 17 186... 

Strong base anion exchangers, 74 395, 411 Strong inversion, in silicon-based semiconductors, 22 239 Strong nitric acid process, materials of construction for, 77 187-188 Strong phosphoric acids, equilibrium composition of, 78 827t Strontianite, 23 317, 321 Strontium (Sr) 23 316-325 chemical properties of, 23 318 economic aspects of, 23 320-321 effect of micro additions on silicon particles in Al-Si alloys, 2 311-312 in ferrites, 77 59... 

Wisconsin nitric acid process, 17 186, 292 Witch hazel distillate... 

Wet Process Phosphoric Acid. A production process flow diagram is shown in Figure 8. Insoluble phosphate rock is changed to water-soluble phosphoric acid by solubilizing the phosphate rock with an acid, generally sulfuric or nitric. The phosphoric acid produced from the nitric acid process is blended with other ingredients to produce a fertilizer, whereas the phosphoric acid produced from the sulfuric acid process must be concentrated before further use. Minor quantities of fluorine, iron, aluminum, sUica, and uranium are usually the most serious waste effluent problems. 

Acidity (as % AcOH), when RDX is Type A(made by nitric acid process) Acidity (as % HN03), when RDX is Type B (made by acetic anhydride process)... 

Properties of RDX. As described above, there are two types of US technical grade RDX, depending on the method of manif Type A, mp 202-203° prepd fcy the nitric acid-process and Type B, mp 192 93° (decomp with si evolution of fumes ), prepd by the acetic anhydride, combination or Bachmann processes... 

T. Ohrui, K. Ohkubo and 0. Imai, Technological Improvements in the Strong Nitric Acid Process , Ammonia P/ant Safety, Volume 21, pp.1 64-I 70, AlChE, New York (1979). 

V. Cavaseno (Ed ), Strong Nitric Acid Process Features Low Utility Costs , Process Technology and Flowsheets, pp.83-86, (reprints from Chemical Engineering) McGraw-Hill Publications, New York (1979). 

D.W. Bolme and A. Horton, The Humphreys and Glasgow/Bolme Nitric Acid Process , Chemical Engineering Progress, March, pp.95-98 (1979). 

The designers of nitric acid processes have generally accepted the chemical steps outlined in Section 1.2.4. Hence, process developments have centred around optimizing the design within the bounds of available equipment, materials of construction, and economics. 

FIGURE 3.1 Flowsheet for dual-pressure nitric acid process. (From Ref. PT I, p. 176 reproduced with permission from American Institute of... 

An example of a process with an intermediate product is the urea process. The second step, starting from ammonia, is over 90% efficient, whereas the total process, having ammonia just as an intermediate product, shows an efficiency of only half of this value. For the nitric acid process, Figure 14.2,... 

The CNA (Concentrated Nitric Acid) process is a general name for processes that make nitric acid more concentrated than the 70% made in conventional processes. 

The water balance in the nitric acid process consists of reaction water, dilution water and water carried with the process streams (see Figure 9.6)220. 

The capital cost of an integrated SCR unit for a new 1,000 tonne/day plant is estimated to be 1.5% of the total capital cost of the nitric acid plant. This cost includes the cost of the SCR catalyst but excludes spare parts. The capital cost of an end-of-pipe SCR unit for an existing 1,000 tonne/day plant is estimated to be 3% to 6% of the total capital cost of the nitric acid plant. But this is very dependent on the type of nitric acid process. The SCR will increase operating costs by 1.1% when NOx in the tail gas is reduced from 1,000 ppmv to 200 ppmv. The maintenance cost of the SCR unit is typically 2.5% of the capital cost97. 

Nickel and its common alloys such as Monel (nickel-copper), Inconel (nickel-iron-chromium), and Duranickel (primarily nickel) can be bonded with procedures that are recommended for stainless steels.35 A simple nitric acid process has also been used consisting of solvent cleaning, immersion for 4 to 6 s at room temperature in concentrated nitric acid, rinsing with cold deionized water, and finally drying. Also, a chromium trioxide-hydrochloric acid process consisting of a 60- to 80-s immersion in acid solution has been suggested. If immersion is impossible, this latter solution may be applied with a cheesecloth after solvent cleaning. The solution is applied to approximately 1 ft2 of the substrate surface at a time, and it remains on the part for approximately 1 min. 

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