Corrosion accidents:- Bhopal tragedy
Corrosion and its types:
A BASIC QUESTION
What is Corrosion ????
DEFINATION:
Corrosion is a natural process, which converts refined metal to their more stable oxide. It is the gradual destruction of materials (usually metals) by chemical reaction with their environment. In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen.
Corrosion is the phenomenon of a metal or an alloy to undergo destruction or degradation by its interaction with the surrounding environment. Many structural alloys corrode merely from exposure to moisture in air, but the process can be strongly affected by exposure to certain substances. Corrosion can be concentrated
…show more content…
This selective leaching of an alloying element from the surface can result in the surface becoming dealloyed and in some cases this dealloying of metal is not limited to the surface and it grows in to the solid causing a serious loss in mechanical strength of the metal or alloy.
6: ENVIRONMENTALLY INDUCED FRACTURE: Application of mechanical stress to a metal or alloy when it is exposed to a chemically reactive environment results in formation and propagation of cracks at points of stresses below those required for cracking by purely mechanical process in absence of corrosive environment.
7: GALVANIC: Because different elements in alloy or metal has different chemical activities, therefore they have different electrochemical properties. When dissimilar metals join in such a way there electrical circuit gets completed due to unfamiliar environment and thus results in corrosion of metal.
8: EROSION: Mixing or stirring of solution can accelerate the rate of corrosion either by increasing the rate of transport to the surface or by mechanically damaging or removing surface films that protect the underlying metal from
…show more content…
All three tanks were in use. It is expected that one tank will be kept free for emergency purposes. In the United States, Japan, and Germany, MIC was either used up as it was produced or stored only for brief periods and never in such huge quantities as in Bhopal. Tank 610 had 6.4 tons of MIC prior to October 7 to which was added MIC produced from October 7 til October 22. Thus MIC was not only kept for 55 days, but Tank 610 contained two separate pools of MIC. It is expected that tanks should be no more than half full; however, prior to the fateful night in Bhopal, the Tank 610 was 87% full, which is far above the recommended capacity of 50% at the West Virginia plant and the 60% specification for the Bhopal plant Tanks containing MIC are required to be kept under refrigeration; this elementary caution was violated at
Bhopal. The Union Carbide manual specifies that the alarm should respond whenever the temperature goes above 11°C; in Bhopal it was set at 20°C. Most evidence suggests that MIC in the Bhopal plant was generally at or above 15°C.
Causes for Bhopal disaster
The main reason behind the Bhopal disaster was the gas
The cause of Union Carbide’s tank 610 MIC leak have two theories. One theory according to the Indian government, that water was introduced through a hose into bleeder A at filter pressure safety valve lines. It happened on the Eve of the disaster when a supervisor ordered an operator, R.Khan to unclog four filter valves near the MIC production area by washing them out with water. Khan connected a water hose to the piping above the clogged valves but neglected to insert a slip blind, a device that seals lines to prevent water leaks into adjacent pipes.
In other words, the alloying element affects the temperature of which the oxide scale forms and its behaviour is at higher elevation temperature as well as gas composition and moisture level [3].
A chemical is a substance used in a chemical process.Everything that has mass is a chemical.Anything that is matter is a chemical. Filtration is the process of separating solid particles from fluids.To evaporate is to change from a solid or liquid to vapor.Alcohol is soluble in water.However, oil is insoluble in water.
Meanwhile, another problem appeared in another part of the plant. The emergency feedwater system, backup to main feedwater, was tested 42 hours prior to the accident. As part of the test, a valve is closed and then reopened at the end of the test. But this time, because of either an administrative or human error, the valve was not reopened. This mistake prevented the emergency feedwater system from functioning. The valve was discovered closed about eight minutes into the accident. After it was reopened, the emergency feedwater system began to work correctly, allowing cooling water...
is 37°C and as soon as you go above this temperature it will cause the
Rationale: This question ties in with the second level of Webb’s DOK because it deals with cause and effect. Also, the students are involved in metal processing.
The purpose of the lab was to show the effect of temperature on the rate of
As for the management of Union Carbide¡¦s Bhopal plant, some steps indeed needed to be improved. Let us take a look at the whole process of the gas leak and see what actions can be improved. The first mistake in my opinion was that R. Khan, an operator in the MIC complex, neglected to insert a slip blind above the point of water entry. This omission violated instructions in the MIC processing manual, the technical manual that set forth procedures established by the chemical engineers who set up the plant. Obviously, the plant failed to emphasize the importance of obeying the processing manual and the danger of disobeying ...
Electroplating is a process of metal finishing that is used by many industries for several applications. The process includes using a metal to cover another metal by electrolysis in order to prevent corrosion. Electroplating gives a wide range of benefits to industries to improve their products. Industries use metals such as silver and gold to decorate jewelry that gives it a shine in order to depict it as expensive and covered with zinc that protects it. Metals such as steel and chromium are greatly used in the auto industry, in which car fenders are covered made with the metals to ensure its shine and that it is rust-resistant. In the 20th century, electroplating plastic has also become common where many household and car products might appear
“The Industrial Revolution was another of those extraordinary jumps forward in the story of civilization” (Stephen Gardiner). One of the major parts of the industrial process has to do with metal production. Welding has been incorporated into the framework of metalworking. Welding dates back to the middle ages where forge welding processes were used to make tools and weapons, commonly known as blacksmiths. It is known that the Egyptians used forms of welding to make gold tools, jewelry, and decoration. During the 1800’s a new process was formed by using carbon electrodes to form an arc. This was done by Sir Humphrey Davy, which carried on to become Carbon Arc Welding and the most used process during the late 1800’s. As time evolved so did the
In May 1982, three American engineers from the chemical products and household plastics division of UCC came to Bhopal. Their task was to appraise the running of the plant and confirm that everything was functioning according to the standards laid down by UCC. The report revealed that the Bhopal plant has lacked a lot of securities and workmanship. The report described the surroundings of the site as being 'strewn with oily old drums, used piping, pools of used oil and chemical waste likely to cause fire. It condemned the shoddy workmanship on certain connections, the warping of equipment, the corrosion of several circuits, the absence of automatic sprinklers and the risk of explosion in the gas evacuation flares. It also reported leaks of phosgene, MIC and chloroform, ruptures in pipe work and sealed joints, absence of any earth wire on one of the three MIC tanks and poor adjustment of certain devises where excessive pressure could lead to water entering the circuits. At the same time, the report expressed concern at the inadequately trained staff, unsatisfactory instruction methods and sloppy maintenance reports. In October 1982, MIC escaped from a broken valve, seriously affecting four workers and causing eye irritation and breathlessness among people in the nearby communities. This incident was a clear indication of the potential risk to public life. In
Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts (soluble-a substance able to be dissolved, especially in water). The process breaks down rocks. These reactions occur particularly when the water is slightly acidic. There are different types of chemical weathering. There’s hydrolysis, which is the chemical breakdown of a substance when combined with water. When water combines with the substances in rocks, it forms new types of substances, which are softer than original rock types.It’s easier to break them apart.There’s oxidation, which is the reaction of a substance with oxygen. When oxygen
- The amount of times the mixture was stirred. We stirred the mixture until the Ammonium Nitrate was dissolved, so the amount of times we stirred after each teaspoon was different.
In such cases, the metallic surface occasionally acts as a catalyst. For example, corrosion and polymerization occurs in cooling water for chemical industry which has slight content of the hydrocarbons. Systems in petroleum processing are susceptible to the polymerization of olefins or accumulation of heavy fractions. High tube wall temperatures may steer to the carbonizing of organic matter. Food industry, for example milk processing, also experiences fouling issues by these chemical reactions. Fouling through an ionic reaction with an progression of an inorganic solid is commonly classified as precipitation fouling (not chemical reaction
Toughness is the ability of a metal to mutilate plastically and to absorb energy in the process before it breaks or fracture. Metals can be heat treated to alter the properties of strength, ductility, toughness, hardness or resistance to corrosion. This can be done by using heat treatment processes which include precipitation strengthening, quenching, annealing and tempering. Annealing and tempering are the most prominent methods for treating metals. A material may become more or less brittle, harder or softer, or stronger or weaker, depending on the treatment used.