When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Sulfate attack in concrete and mortar - Wikipedia

    en.wikipedia.org/wiki/Sulfate_attack_in_concrete...

    Oxidation of pyrite in clay formations in contact with concrete – this produces sulfuric acid which reacts with concrete. Bacterial activity in sewers – anaerobic sulfate reduction at work in the organic-rich sludges accumulated under water in the conduits produces hydrogen sulfide gas (H 2 S).

  3. Iron(II) sulfide - Wikipedia

    en.wikipedia.org/wiki/Iron(II)_sulfide

    These metal sulfides, such as iron(II) sulfide, are often black or brown, leading to the color of sludge. Pyrrhotite is a waste product of the Desulfovibrio bacteria, a sulfate reducing bacteria. When eggs are cooked for a long time, the yolk 's surface may turn green.

  4. Iron sulfide - Wikipedia

    en.wikipedia.org/wiki/Iron_sulfide

    Iron sulfide or Iron sulphide can refer to range of chemical compounds composed of iron and sulfur. Minerals. By increasing order of stability: Iron(II) sulfide, FeS;

  5. Iron (II) sulfate - Wikipedia

    en.wikipedia.org/wiki/Iron(II)_sulfate

    Iron(II) sulfate outside a titanium dioxide factory in Kaanaa, Pori, Finland. Upon dissolving in water, ferrous sulfates form the metal aquo complex [Fe(H 2 O) 6] 2+, which is an almost colorless, paramagnetic ion. On heating, iron(II) sulfate first loses its water of crystallization and the original green crystals are converted into a white ...

  6. Acid sulfate soil - Wikipedia

    en.wikipedia.org/wiki/Acid_sulfate_soil

    These soils contain iron sulfide minerals (predominantly as the mineral pyrite) and/or their oxidation products. In an undisturbed state below the water table, acid sulfate soils are benign. However, if the soils are drained, excavated or otherwise exposed to air, the sulfides react with oxygen to form sulfuric acid. [1]

  7. Pourbaix diagram - Wikipedia

    en.wikipedia.org/wiki/Pourbaix_diagram

    Pourbaix diagram of iron. [1] The Y axis corresponds to voltage potential. In electrochemistry, and more generally in solution chemistry, a Pourbaix diagram, also known as a potential/pH diagram, E H –pH diagram or a pE/pH diagram, is a plot of possible thermodynamically stable phases (i.e., at chemical equilibrium) of an aqueous electrochemical system.

  8. Biogenic sulfide corrosion - Wikipedia

    en.wikipedia.org/wiki/Biogenic_sulfide_corrosion

    The hydrogen sulfide gas is biochemically oxidized in the presence of moisture to form sulfuric acid. The effect of sulfuric acid on concrete and steel surfaces exposed to severe wastewater environments can be devastating. [1] In the USA alone, corrosion causes sewer asset losses estimated at $14 billion per year. [2]

  9. Iron - Wikipedia

    en.wikipedia.org/wiki/Iron

    The best known sulfide is iron pyrite (FeS 2), also known as fool's gold owing to its golden luster. [63] It is not an iron(IV) compound, but is actually an iron(II) polysulfide containing Fe 2+ and S 2− 2 ions in a distorted sodium chloride structure. [67] Pourbaix diagram of iron