Corrosion effect of acid

Phosphoric acid is poisonous only at a high concentration, when it shows the usual corrosive effects of acids.2 The salts, and even the acid in low concentration, favour the growth of moulds and fungi, provided that the hydrogen-ion concentration also is favourable. 

Nitric acid reacts energetically at ordinary temperatures, with formation of the nitrate and of the oxides of nitrogen. The behaviour of the metal with hydrochloric acid is similar to that of lead. The action of concentrated sulphuric acid and of nitric acid finds application in the separation of alloys of gold and silver. The corrosive effect of acids is accelerated by the presence of an oxidizer.5... 

Because the literature on the effects of acid deposition on PCC is limited, the large amount of literature dealing with the corrosive effects of acids, acid waters, and sulfates on concrete was reviewed in an attempt to estimate the effects of acid deposition on PCC (25-48). 

Supplit, R., Koch, T. and Schubert, U. (2007), Evaluation of the anti-corrosive effect of acid pickling and sol-gel coating on magnesium AZ31 alloy , Corros. Sci., 49,3015-23. 

RW. Lipfert, M. Benarie, and M.L. Daum, Metallic corrosion damage functions for use in environmental assessments, in Proceedings of the Symposia on Corrosion Effects of Acid Deposition and Corrosion of Electronic Materials, Las Vegas, NV, 1985, R Mansfeld, S.R Haagenrud, V. Kucera, RH. Haynie, and J.D. Sinclair (eds.). The Electrochemical Society, Rennington, NJ, vol. 86(6), p. 108 (1986). 

S.E. Haagenrud, J.R. Henriksen, and R. Gram, Dose-response functions and corrosion mapping of a small geographical area. Presented at the Electrochemical Society Symposium on Corrosion Effects of Acid Deposition, Las Vegas, NV, October 1985, Norwegian Institute for Air Research, NILU R 53/85, (1985). 

Penn, J. H. and Murray, G. A. W., Effect of Acidic Gelatinous Materials on Pitting Corrosion of Aluminium Hollow-ware , Br. Corros. J., 2, 193 (1967)... 

A volatile, amine-based chemical treatment usually added to the boiler FW, designed to neutralize the corrosive effects of carbonic acid in steam/condensate and raise condensate pH. 

F. Mainier, C. A. Saliba, and G. Gonzalez. Effectiveness of acid corrosion inhibitors in the presence of alcohols. SPE Unsolicited Paper, SPE-20404, July 1990. 

In a demonstration of the corrosive effect of fuming nitric acid on rubber tubing, soon after the initial vigorous reaction had subsided, a small explosion followed by ignition occurred. (The sulfur compounds used to compound the rubber were probably involved) [1], Leaded neoprene rubber gloves, (the lead present as red lead, Pb304) used in the nuclear industry, may form explosive compounds in contact with nitric acid. It is hypothesised this could be lead fulminate formation. Since mixtures of lead nitrate with organics, or with sulfur from vulcanisers, would be explosive, this seems unduly complicated [2]... 

The corrosive effects of sulfuric acid on teeth with chronic exposure are well established." The damage, etching of dental enamel followed by erosion of enamel and dentine with loss of tooth substance, is limited to tbe parts of the teeth that are exposed to direct impingement of acid mist upon the surface. Although etching typically occurs after years of occupational exposure, in one case exposure to an average of 0.23mg/m for 4 months was sufficient to initiate erosion. ... 

Some of the most dramatic environmental effects of acid deposition have involved buildings, statues, monuments, and other structures made of metal and stone. The explanation of this kind of damage is obvious Acids in acid deposition react with metals and with many of the compounds of which rock and other building material are made. For example, corrosion occurs when metals such as iron are exposed to hydrogen ions in the presence of oxygen ... 

Engine lubricant formulators are aware of the problems associated with fuel sulfur and develop products to help combat its corrosive effect. Lubricants containing overbased calcium sulfonates and phenates are utilized to chemically neutralize the acids which form as a result of burning fuel sulfur. These oils can be effective at preventing the corrosive effects of fuel sulfur. However, the oils must be frequently changed to ensure that the acid-neutralizing effect is maintained. 

Lead is an acid-resistant material and the lead sulphate formed on the surface does not contaminate the product of nitration, merely forming a permanent protective layer against the corrosive effects of the nitrating acids. However, the cover of lead sulphate acts as a thermal insulator, which is undersirable since it lowers efficiency of operation, e.g. when leaden cooling coils are used. 

The materials handled in the bins were 20% solids by weight, flow of 2.9 tons of water per hour and 47 gallons/minute of pulp. The size of the material was 100 to plus 325 BSS mesh. Maximum acid concentration was 20% hydrochloric acid. The temperature in the system was 60°C. A 6 mm thick natural rubber lining of shore hardness 50°A was used to protect the equipment against the abrasive environment as well as the corrosion effects of hydrochloric acid. 

In a demonstration of the corrosive effect of fuming nitric acid on mbber tubing, soon after the initial vigorous reaction had subsided, a small explosion followed by ignition occurred. (The sulfur compounds used to compound the rubber were probably... 

Other metals, such as copper, nickel, or silver, have been used as electrode materials in connection with specific applications, such as the detection of amino acids or carbohydrates in alkaline media (copper and nickel) and cyanide or sulfur compounds (silver). Unlike platinum or gold electrodes, these electrodes offer a stable response for carbohydrates at constant potentials, through the formation of high-valence oxyhydroxide species formed in situ on the surface and believed to act as redox mediators (40,41). Bismuth film electrodes (preplated or in situ plated ones) have been shown to be an attractive alternative to mercury films used for stripping voltammetry of trace metals (42,43). Alloy electrodes (e.g., platinum-ruthenium, nickel-titanium) are also being used for addressing adsorption or corrosion effects of one of their components. The bifunctional catalytic mechanism of alloy electrodes (such as Pt-Ru or Pt-Sn ones) has been particularly useful for fuel cell applications (44). 

Corrosion. A more serious effect and one of great economic importance is the corrosive action of acid gases on building materials. Such acids can cause stone surfaces to blister and peel mortar can be reduced to powder. Metals are also damaged by the corrosive action of some pollutants. Another common effect is the deterioration of tires... 

Corrosion studies have been rare. (8), copper, or iron were corroded by carbon tetrachloride when exposed to Co-60 radiation (78). Alkyl halides enhanced the corrosive effect of benzoic acid on iron (79). (1) was found to promote stress-corrosion cracking in zirconium alloys used in nuclear reactors (80). 

Ammonia gas is injected into treated water using systems and equipment similar to those used for chlorine gas. Aqua ammonia is handled using systems similar to those used for sodium hypochlorite. This form of ammonia is basic and has a strong odor, but is not corrosive. For ammonium sulfate powder, a 25-30% solution is prepared in a plastic or fiberglass container and added to the water by means of a chemical metering pump. Equipment similar to that used for handling calcium hypochlorite can be used for this process. Solutions of ammonium sulfate are stable, but acidic, and, therefore, corrosive to some metals. Materials that withstand dilute sulfuric acid will also withstand the corrosion effects of dilute ammonium sulfate solutions. 

After ingestion, emesis should not be induced due to the corrosive effects of chromium compounds. Ascorbic acid should be administered orally or nasogastrically to help reduce the hexavalent compounds to the trivalent forms. Dilution of the Cl tract contents is indicated if the dilution can be accomplished within a few minutes after the ingestion. 

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