Corrosion Control By Deposition Of Ca Co3

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Proposal on ways to protect water pipe from corrosion

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Corrosion Control By Deposition Of Ca Co3

  1. 1. Corrosion Control by deposition of CaCO 3 Mahfoodh Mohamed Al-Shuely Consultant, Asst. Researcher, SQU MSC. Environmental Protection & Management, Edinburgh BSc. Chemistry, SQU
  2. 2. Contents <ul><li>What is corrosion </li></ul><ul><li>Causes of corrosion </li></ul><ul><li>Types of corrosion </li></ul><ul><li>Prevention of Corrosion </li></ul><ul><li>Proposed project </li></ul>
  3. 3. Corrosion <ul><li>Can be viewed as the process of returning metals to their natural state- the ores from which they are originally obtained </li></ul><ul><li>Consists of a series of electrochemical reaction occurring at the metal surface in contact with water and its constituents </li></ul>
  4. 4. Corrosion <ul><li>4Fe 2+ (aq) +O 2(g) +(4+2n)H 2 O (l) 2Fe 2 O 3 .nH 2 O (s) +8H + (aq) </li></ul><ul><ul><ul><ul><ul><li> Rust </li></ul></ul></ul></ul></ul>
  5. 5. Causes of Corrosion <ul><li>Metals corrode because they oxidize easily </li></ul><ul><li>Large difference in reduction potentials between oxygen and most metals causes oxides to be formed (rust) </li></ul><ul><li>Microbes create areas with different concentration in oxygen, minerals and metals </li></ul>
  6. 6. Types of Corrosion <ul><li>General wastage of material- Uniform corrosion </li></ul><ul><li>Galvanic corrosion-dissimilar metals in contact </li></ul><ul><li>Pitting-localized attack </li></ul><ul><li>Intergranular corrosion </li></ul><ul><li>Stress corrosion </li></ul><ul><li>Erosion-corrosion </li></ul><ul><li>Corrosion fatigue </li></ul><ul><li>High temperature oxidation </li></ul><ul><li>Hydrogen embrittlement </li></ul>
  7. 7. Prevention of Corrosion <ul><li>Galvanizing- Zinc coating of steal </li></ul><ul><li>Alloying- Chromium and Nickel coating to form oxides </li></ul><ul><li>Corrosion inhibitor chemicals (carbonate, silicate, phosphates) </li></ul><ul><li>Cathodic protection (most used in protecting buried pipelines and fuel tanks) Magnesium anode often used to furnish electrons </li></ul>
  8. 8. Corrosion prevention
  9. 9. Proposed Project <ul><li>Altering certain parameters of water to force deposition of CaCO 3 </li></ul><ul><li>CaCO 3 acts as a barrier between the metal surface and the water </li></ul><ul><li>No addition of foreign elements in water nor altering metal properties </li></ul><ul><li>Computer aided program predicts behaviour of protective film </li></ul><ul><li>CHEAP </li></ul>
  10. 10. International Experience <ul><li>Recent studies published in Desalination (issue 213, 2007) about municipality of Hrysoypolis in Greece confirmed the benefits of CaCO 3 deposition in pipeline protection </li></ul>

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