The burning of fuel oil with high sulfur content in diverse industrial segments results in the generation of oxidized sulfur compounds (SO x). These emissions, directly or indirectly, lead to the deterioration of air quality with consequences including the development of lung diseases in the surrounding population, the generation of acid rain and damage to civil constructions, such as public buildings, public squares, historic monuments, bridges, etc. This article describes the mechanisms of corrosion that occur in reinforced concrete deterioration observed in an industrial plant by the action of direct emissions of sulfur dioxide. SO2 in this case study is from the burning of fuel oil high sulfur content from chimney of an industrial boiler. The deterioration of concrete was evaluated in the laboratory showing the formation of calcium sulfate and calcium sulfate hydrate associated with aluminum oxide (Al 2 O 3) and calcium oxide (CaO).

a b s t r a c tThis article presents a case of scale on steam generator pipe of high pressure resulting from a failure in the ion exchanger unit of the water system power supply. This generator was injecting steam into oil wells for enhanced oil recovery at a temperature and pressure of about 350°C and 17.0 Mpa, respectively. For safety and operational performance, routine inspections on the steam generator are carried out. The steam injection was interrupted by a thick layer of incrustation in a vapour injection pipe. Analysis showed a scale of calcium carbonate (CaCO 3 ), magnesium and iron silicate [(Mg,Fe) (CaCO 3 .MgCO 3 ) with a thickness of 1.8 to 2.3 mm adherent to a film of magnetite (Fe 3 O 4 ), which protects the carbon steel pipe from generated steam. To put the steam generator in safe operating condition again, the scale of calcium carbonate was removed with hydrochloric acid solution and a corrosion inhibitor. Chemical analyses and X-ray diffractometry analysis were performed in order to identify the scale formation on the inner walls of the pipe. Laboratory testing showed that acid removal with a mixture of hydrochloric acid and hydrofluoric acid with propargyl alcohol (corrosion inhibitor) achieved efficiency exceeding 90%.