Rubber lining ammonia

Materials of construction for ammonia are dependent on the operating temperature. Whilst mild steel may be used at ambient temperature, special costly steels are required at low temperatures to avoid embrittlement. Impurities in liquid ammonia such as air or carbon dioxide can cause stress corrosion cracking of mild steel. Ammonia is highly corrosive towards copper and zinc. Rubber lined steel construction is suitable for service at ambient temperature. 

Typical applications for soft natural rubber linings include chemical storage tanks to handle phosphoric acid (37%), hydrofluosiUcic acid, alum, chlorides and sulfates of ammonia, cadmium, iron phosphoras and sodium, inorganic salts in gen-... 

From the outset the Nazi nerve gas project was beset by difficulties, and it took over two years, until April 1942, to get the factory operational. Many of the chemicals needed to make the liquid nerve gases were found to be exceptionally corrosive and all iron and steel equipment had to be plated with silver. The nerve gas itself was so highly toxic that the whole of the plant was enclosed in double glass-lined chambers with pressurized air circulating between ,5 and all apparatus had to be decontaminated with steam and ammonia. The workers wore respirators and special protective suits made of cloth sandwiched between two layers of rubber which were discarded after every tenth wearing. If anyone was suspected of having been contaminated, their clothes were torn off and they were immersed in large baths of sodium bicarbonate solution. 

PERSONAL PROTECTION rubberized outerwear is required wear safety goggles and self-contained breathing apparatus air lines or ammonia canister masks are required equipment should not have copper, zinc, aluminum, or galvanized parts emergency showers and eyewash baths should be provided in the immediate work area. 

In most cases, it is normal to maintain a uniform acid feed for the desired output level and to control the ammonia addition to achieve a steady pH of 8.0. The control system should include an audible alarm and provisions for shutting off the acid if the pH faDs below 7.0 otherwise, those components in the system not protected by rubber or plastic linings (e.g., the centrifuge) would be quickly damaged by corrosion. Slurry is withdrawn from the saturator at about 80% solids concentration, and the ammonium chloride crystals are separated and rinsed in stainless-steel centrifuges. In some cases, drying is... 

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