Modern Hot Metal Desulfurization

Modern Hot Metal Desulfurization Modern Hot Metal Desulfurization And Dephosphorization Technologies Introduction The purpose of phosphorus and sulfur removal is to decrease the concentration of these particles along with the undesired inclusions (oxides, borides, nitrides, carbides, and chlorides) to accomplish the final product quality requirements [5]. Dephosphorization involves low temperature, high slag basicity (CaO/ SiO2 ratio) and high oxygen activity whereas desulphurization entails high temperature, high slag basicity (CaO/ SiO2 ratio) and low oxygen activity. Initially, dephosphorization was performed by the addition of iron ores in the blast furnace runner. Soda ash (Na2CO3) was used in the blast furnace house during desulphurization. Subsequently, dephosphorization was improved by the subsurface injection of reagents in vessels, such as torpedo or submarine cars. Desulfurization was enhanced by co-injection of lime and magnesium into the hot metal transfer ladles [6]. The following dephosphorization and desulphurization technologies are reviewed: 1. Dephosphorization by the multirefining converter (MURC) process 2. Dephosphorization using CaO aggregates 3. Desulfurization by Magnesium 4. Desulfurization by flux injection using a new kinetic model 5. Desulfurization by the CFD modeling 1. Dephosphorization By The Murc Process The multirefining converter (MURC) process claims to improve the efficiency of the dephosphorization procedure by reducing the cost and minimizing the slag volume. It is a new hot metal pretreatment in which dephosphorization and decarburization processes are developed in the same converter for further reduction of the decarburization slag. The MURC process reduces the amount of slag by 50 % in comparison to the conventional pretreatment processes (30 %). The decarburization slag is continuously recycled (Figure 1). A low basicity dephosphorization slag is discharged from the MURC due to the high amount of total iron in the slag (T Fe) and no desiliconization treatment of the hot metal. This results into a valuable utilization of the dephosphorization slag in the steelmaking process. 2. Dephosphorization Using Cao Aggregates The multiphase dephosphorization slag is analyzed through the addition of calcium ferrite flux powder into hot metal. It is observed that high [Si] content (0.15 %) shows a similar CaO efficiency for dephosphorization than low [Si] content (0.00 %). The low [Si] content exhibits calcium phosphate (3CaO.P2O5) whereas high [Si] content shows a combination of calcium silicate (2CaO.SiO2), and calcium phosphate. The formation of these solid phases explains a similar CaO efficiency under different [Si] content. 3. Desulfurization By Magnesium Desulfurization is enhanced by the stirring effect of Mg bubbles in the hot metal. The reaction speeds up by the addition of lime and CaC2. These desulfurization reagents were tested in ArcelorMital Indiana Harbor. The typical inclusions before reagent injection were TiC and MnS. TiO2 is added to protect the graphite lining in the blast furnace. MgS + TiC and MgS were the most frequent inclusions after the reagent injection. MnS inclusions were not observed after this stage. This means, most of these inclusions floated up at the end of desulphurization. Further improvement of desulfurization can be achieved by Al addition. The latter reacts with lime to form lower melting point calcium aluminates. 4. Desulfurization By Flux Injection Using A New Kinetic Model Desulfurization is performed by introducing powder reagents (CaO, calcium carbonate, calcium diamide carbonate) into the hot metal using either core wired or a carrier gas (nitrogen). This creates a complex variety of interfaces in torpedo ladles (Figure 2) [7]. There are two reaction modes that are present in the heterogeneous/ immiscible phases. The first mode is related to the transitory reaction between the liquid steel and powder particles. The second mode is the permanent reaction between the slag on the surface and the molten steel. Desulfurization in torpedo ladles. The interfaces are: (1) Jet zone; (2) bubbles and particles rise in the plume zone; (3) bubbles emerge in the breakthrough zone; (4) slag zone; (5) gas-slag-metal emulsion forms in the dispersion zone; (6) metal reacts with lining in the lining zone; (7) lowest stirring intensity in the intermediate zone Several parameters influence the desulfurization of hot metal and are predicted by a new model of submerged powder injection. The total amount of the flux is considered to be liquid at steelmaking temperature and the injection rate along with the time lapse can be determined. The total sulfur removal rate for both the permanent contact (top slag) and transitory (injection powder) mode is obtained by the following equation, The right hand side of the reaction is related to the transitory reaction. This equation is only useful during the powder injection. After that, the right hand side becomes worthless. Sulfide solubility in slag is restricted. Once the sulfide solubility limit is reached, a pure sulfide phase grows within the slag to absorb the excess of sulfur. Sulfide saturation may occur before the slag and metal reach equilibrium. The speed of the reaction is reduced until the sulfur content is dropped. Excess of sulfur in permanent reactions produces a reversion reaction and further desulphurization cannot occur. The transitory reaction removes the excess of sulfur by the continuously addition of fresh powder into the torpedo ladle. It is also recommended to deslag after powder injection. Figure 3 is divided into [% S] wt % and reaction rate. The experimental results are obtained from the 20 CaO-60CaF2-20Al2O3 (by weight) powder injection under an argon atmosphere into 3.4-3.8 kg cast iron at 1310 Â °C. Once the slag (permanent-contact reaction) experiences an excess of sulfur at 420 s, the sulfur concentration decreases continuously until 950 s. The contributions of the permanent and transitory reactions are also displayed. The permanent reaction increases with time until it is saturated. The transitory reaction never approaches to saturation conditions. The difference between these two reactions is not significant large. Therefore, the contribution of these both reactions is generally equal. 5. Desulfurization By CFD Modeling Synthetic slag is used on the desulfurization process due to its reuse in several treatments. The sulfur is transferred to the synthetic slag followed by slag regeneration. Slag regeneration is performed by the oxygen injection to produce gaseous sulfur dioxide (Equation 3). The sulfur distribution also differs from the slag and the metal once desulfurization begins (Figure 4). A porous plug at the bottom of the vessel is used to inject nitrogen in the hot metal. The fluid velocity is increased to optimize the desulfurization rate to improve sulfur transport. Therefore, CFD analyzes the desulfurization and slag regeneration processes to optimize the plug position and calculate the drift velocity of gas bubbles, desulfurization rate, among other parameters, for future design of desulphurization processes. Conclusions Multirefining converter (MURC) (1) Dephosphorization and decarburization are carried out in the same converter, reducing the slag volume for better industrial, economical and environmental purposes (2) The dephosphorization efficiency is increased by greater amounts of CaO to produce solid phases, such as 3CaOP2O5 and 2CaSiO2 Desulfurization by Mg (1) TiC particles are nucleation sites for MnS and MgS (2) MgS inclusions are the most frequent particles after the reagent injection Desulfurization by flux injection using a new kinetic model (1) A new model is developed to evaluate and identify separately the transitory and permanent reactions (2) This model helps to predict the excess of sulfur to avoid reversion of it in the hot metal (3) The contributions of the transitory and permanent contact reactions are observed to be in a similar proportion, concluding equal influence in the powder injection technique CFD Modelling (1) The desulfurization and slag regeneration are successfully modeled using thermal and transport mechanisms References [1] S.Y. Kitamura, K. Yonezawa, Y. Ogawa, N. Sasaki (2002). Improvement of reaction efficiency in hot metal dephosphorization, 29 (2), 121-124 [2] Q. Liu, H. Pielet, P. Kaushik B. Chukwulebe (2009). AISTech 2009 Proceedings. An investigation of hot metal desulfurization by Mg, 1, 821-827 [3] S. Ohguchi and D.G.C. Robertson (1984). Kinetic model for refining by submerged powder injection: Part 1 Transitory and permanent contact reactions, 11(5), 261-274 [4] S. Pirker, P. Gittler, H. Pirker J. Lehner (2002). Elsevier. CFD, a design tool for a new hot metal desulfurization technology, 26, 337-350 [5] X. LV and L. Zhang (2008). Removal of impurity elements from molten aluminum: part 1. A review. 1, 1-35 [6] R.J. Fruehan (Ed.) (1998). The making, shaping and treating of steel (11th ed.). Pittsburgh: The AISE Steel Foundation [7] M. Sadmi S. Ashhab (2007). Jordan Journal of Mechanical and Industrial Engineering. Application of neural net modeling and inverse control to the desulfurization of hot metal process, 1 (2), 79-84

Book Report On a Dramatic Death :: essays research papers fc

Book Report on "A Dramatic Death" This story starts off with the Dorking Drama Group who are making a play everything is going well until gruesome accidents start happening but the group ignores it until a prop falls down and kills someone. The police do a investigation but conclude that it was a accident so the play goes on, but everybody is convinced it was foul play and everyone in the drama group is a suspect. The cast members start investigating the murder by themselves and everybody starts turning against each other. In the end two cast members named Steve and Claire find out the murder is Claire because they themselves were attacked by her but they identified her. Emma was a jealous cast member who loved Steve but Claire was Steve's girlfriend, Steve always treated her like a sister but she wanted more than that and went to great lengths to achieve. CHARACTER ANALYSIS The main characters in my book are Steve and Emma. Steve was a popular good looking guy who all the girls liked. He didn't like school that much expect the Dorking Drama Club where he acted in the play, he had a sister and Steve was very careful to trust anyone during all the murder. Emma was very fond of Steve but because she was Steve's sister's friend for so long Steve treated her as a sister, which she didn't like. Emma became so fond of Steve that she start doing all these gruesome things and in the end she went to a mental hospital. Emma liked to be in the play a lot and she was said to have a very over active imagination. SETTING The setting was in a small quiet town called Dorking, the play took in a high school drama room. The setting brings people together (the drama group) which brings conflicts. The town was described to bring a spooky setting to the novel. THEME The theme of this novel is that we shouldn't trust everybody we know no matter how close they are. In the novel the murder is found to be a very close friend to everyone. Everyone should be considered a suspect. This book was written is for to show the great lengths that some people will go to for love. CHAPTER 1 The Dorking Drama club is getting ready for a play and everybody is joking around and acting calm. When they are rehearsing and somebody opens a prop they scream and find there is a dead cat in the box, everyone wonders who is capable of doing such a thing like this.

Living Deficiently or Energy-Efficiently :: Economy Pollution Papers

To live deficiently or energy-efficiently: that is the question. Although the majority of us are aware of the pressing environmental problems we face daily, we are not very aware of the urgency to find a solution to them. Life on earth is built up like a wagon wheel; we can remove a few of those spokes and we might still be able to travel safely, but eventually the wheel will weaken and collapse. At that point, no amount of human ingenuity will allow us to reconstruct the wagon wheel so we can keep traveling on to the future. This fact is obvious, given our inability to completely clean up any damage our pollution has done to the environment—how can we expect to rebuild or repair a collapsed planetary ecosystem? We cannot keep consuming resources and damaging the environment at our current exponential rate. Exponential growth implies infinite expansion, but our Earth is finite, and its resources are finite. If something is not done about our wasteful use of the planetâ₠¬â„¢s energy and resources, our lives will be made miserable and desperate as the natural processes which support human life collapse like a flimsy wagon wheel made of sludge and decaying tree stumps. We will be living deficiently, if at all, according to our current standards of living. Pollution cleanup is no good; continuing to use the current rates of energy that we use without change is no good. We must concentrate on preventing environmental problems in the first place, and what’s more, we must figure out a simple, economical, and practical way that each of us can do it. This solution is energy-efficiency. Series of Topic Sentences to Follow Outline: It is necessary to find a practical resolution to environmental problems. Examples of these environmental problems include: These environmental problems pose a serious threat to humans because the planetary ecosystem is being slowly destroyed. We often like to use the less-impacting terms â€Å"degraded† or â€Å"injured,† but we shouldn’t use diction to hide the truth. By flagrantly using unnecessary quantities of energy, we are gradually destroying our environment—not â€Å"degrading† or â€Å"injuring† it, but destroying it. Our environmental problems are caused by pollution release, resource overuse and destruction, and carelessness towards the environment. The source of all these problems is the lack of human energy-efficiency in manufacturing products and, with greater contribution to the problem, the lack of energy-effiicient lifestyles.

Research Proposal Childhood Obesity Essay

The topic of this research proposal is addressing childhood obesity in the United States. This epidemic has been going on for many years now and has become an issue most recently being addressed by the United States government through their task force, which hopes to end this problem. By reviewing the many factors involved which include economic boundaries for the children’s families, early education in nutrition, and progress made in battling this epidemic thus far, we will be able to determine when it is the best time to introduce good nutritional knowledge and application, as well as physical activity, for children in the United States in hopes of ending this problem overall. In order to determine this answer, the researcher will need to research the changes that have taken place thus far by reviewing articles that show what certain states have been actively promoting healthy eating and physical activity, like in Portland ME who has educational programs for residents. This program also allows for scholarships for these programs for families who cannot afford the classes. The researcher will also have to review articles in the ProQuest database that show what has been studied so far regarding nutrition for young children as well as other sources like the White House website articles related to the task force being led by First Lady Michelle Obama. The researcher will also need to show an overview of the current problem at hand with one in three children in the country qualifying as obese. The researcher will review some of the problems that may be contributing factors like target marketing to children by fast food establishments and limited physical activity by children today, By reviewing all of this information, the researcher should be able to show progress made toward ending this problem and answer when good nutrition and physical activity should be introduced in a child’s life.

Atticus, Throughout to Kill a Mockingbird Essay

Throughout the novel, To Kill a Mockingbird, although Atticus Finch appears to be a loving and caring father, he proves himself to be more of a friend through the eyes of his children. The author, Harper lee, created Atticus to be a loyal friend to Jem Finch and Scout Finch. Atticus has potential to be a friend to his children because, first of all, the children call him by his first name. Secondly, he seldom scolds his children. Atticus has little or no rules set for his children to abide by. Lastly he does not try to mold his off springs into something they are not, though he does supply them with good advice. Typically adults and parents think that it is more respectful for children, particularly their own, to not call them by their first names. Jem and Scout refer to their father as â€Å"Atticus.† Scout asks her father, â€Å"Are we poor, Atticus?† (pg. 21) this shows that she calls her father by his first name on a regular basis. Jem says to his father while reque sting permission from him, â€Å"Atticus, if it’s alright with you†¦.† (pg. 61). This shows that even the older son refers to his father as Atticus. â€Å"†¦ Jem asked Atticus if he remembered anybody who ever won†¦Ã¢â‚¬ , as Scout narrates her story, she still refers to her father as â€Å"Atticus.† Throughout the story, Atticus never shows any sign of being offended or upset with his children calling him by his first name, like a friend. All through the novel, never once did Atticus scold his children for inappropriate behavior. The Finch’s had over a poor boy, named Walter. Scout insulted him with out understanding how it was rude,â€Å"†¦Atticus shook his head at me again. ‘But he’s gone and drowned his dinner with syrup†¦Ã¢â‚¬â„¢Ã¢â‚¬ (p24). All Atticus did was shake his head; he left the rest of the punishing up to Calpurnia, the nanny. When Jem and Scout snuck into the court case that they knew they were not supposed to be in, Atticus did not show the slightest bit of aggravation with them. â€Å"†¦A tticus and Calpurnia met us downstairs. Calpurnia looked peeved, but Atticus looked exhausted,†(pg. 206). When Jem got furious with a horrible old lady, Mrs. Dubose, he destroyed her garden out of anger. When Atticus found out that Jem did this, he says, â€Å"†¦I strongly advise you to go down and have a talk with Mrs. Dubose†¦come straight home afterward.†(pg. 104). Normally, if friends get upset with each other, they do not have the right to â€Å"punish† their friend. Atticus has that right as a parent, but chooses not to use it. Many parents set rules and restrictions for their children. Atticus, for some reason, does not feel it necessary for his two young children to have rules to abide by. The only rules that he ever gave to his children were to not go near the â€Å"Radley house† anymore after they had been teasing Boo Radley in the front yard. It is not common for friends to set rules for one another, but very common for parents to want their children to know where their boundaries lye. Jem and Scout don’t have any rules set by their father to follow, and no known consequences for breaking any rules. Atticus Finch does not try to influence his ideas or beliefs about things on his children. He does not â€Å"make† his children into something they are not, just because that’s what he believes. Most parents try to get their off springs to believe the same things they do, or want the same things they want. Atticus just teaches his kids to the best of his ability through his advice. When the teacher, Miss Caroline, was upset with the fact that Scout was being taught how to read by her father, Scout got the idea of not liking school anymore. Atticus made a compromise with her saying that if she was good in class, then he would continue reading to her. This shows that Atticus was not going to force Scout to like school just because he thought it was a good decision. When scout got into a fight with Cecil Jacobs, Atticus said, â€Å"†¦you just hold your head high and keep your fists down. No matter what anybody tells you, don’t let ‘em get your goat. Try fighting with your head for a change, it’s a good one†¦Ã¢â‚¬ (pg. 79) this is important because it shows that he is not forcing his daughter to think some way, or be someone else, he is not even getting mad at her; he is just giving her good advice. When Jem and Scout got guns for Christmas, Atticus told them one thing, â€Å"†¦Shoot all the bluejays you want, if you can hit ‘em, but remember it’s a sin to kill a mockingbird.† This shows that Atticus is not threatening his children with this statement, he is just simply giving them the best advice he can in this situation. Friends do not expect each other believe the same things they believe, but just hope that people will take their advice into thought. Throughout the novel although Atticus Finch appears to be a loving and caring father, he proves himself to be more of a friend through the eyes of his children. He shows himself to have much potential as a loyal friend to his children. Maybe Atticus as a loyal friend to Jem and Scout was more meaningful than him being a father figure.

Discrimination with “A House on Mango Street” Essay

In the society of today, discrimination and other similar ideas are not suppressed so that they are free to roam our cities, states, countries, and finally the whole world. Still, different sides of the world have different types of discriminations. There are some about animals, race, etc. But the worst possible is discrimination against the opposite sex; cause then those people would be against about 50 percent of the world’s population of humans. So, those who oppose this would try to show the world that the idea of sexism is wrong, and Sandra Cisneros is one of then. She indirectly discusses it in a book, â€Å"House on Mango Street.† This book, â€Å"The House on Mango Street† by Sandra Cisneros, showed feminism and machismo in the Latino culture. For example, I quote, â€Å"I thought I would because he was so old and just as I was about to put my lips on his cheek, he grabs my face with both hands and kisses me hard on the mouth and doesn’t let go.†(p.55) In this quote, the man, who represents the machismo side, tries to take control of Esperanza, which is in the feminism side. This shows an example for power between each other and the thought that the sexes are unequal, unbalanced, and that the male side has more power. For, is the man in the story didn’t think that he could kiss Esperanza and get away with it because he has the right to do so, then he wouldn’t have done so. Just because the society that Esperanza lives in believe that women have no right in the governments or any other part of the society than to care for the family that she lives in and nothing else. So, taking the machismo’s side, first of all I think that it is wrong and that all people are on the same level of equality, its just that some prove themselves more valuable to others so that they have more power in the real world but no person has power over another person. Women’s rights is another important idea of discriminations. An example from this book would be, â€Å"Then Rafaela, who is still young but getting old from leaning out the window so much, gets locked indoor because her husband is afraid Rafaela will run away since she is too beautiful to look at.†(p.79) In this part of the story, the one on the feminism side is being locked up and prevented from doing what she wants to do. In my point of view, plus my previous experiences, I know that no one likes to be locked up and not enjoy  the joy while is possible to do so. Also, it affects how the affected person would respond to others when they are free because they would have never even touched the real world. It would have both physical and mental effects. In addition to that, the women shouldn’t be locked up and more they are limited, the more they would be afraid of the world outside and surrounding them. But, even though most women who are locked up in their own house would be afraid of the world outside, in the very inside, there would be a place where they are longing to transform the musty air they breath to fresh. The dull and bitter papaya and coconut juice would then change into sugar and bubbly drinks. All these would be incomplete without some equality in this society and world. There are places for everyone in this world, but sometimes there are a few people who will never know where they fit. These people are ignored and need places to belong to. For example, Esperanza needs a home of her own because the house she is living in now brings her and her family shame. In the hierarchy of needs, love and caring is one of the parts in it and when the hierarchy is incomplete, there would be problems and disorders. These women who are fighting hard not only for freedom, but also their lives, and they are least likely to succeed when the opposite sex are constantly harassing them and don’t make them feel that they belong. Some strong willed ones would find a way to escape their treacherous would, but that does not work for every abused woman. As a result, the men would give the women so hard of a time to live their lives that they would even fear to even think about escaping their present life. They are why equality must be achieved throughout the world. All that is done and said, there is only one thing left to do. Words may change people’s thoughts and ideas, but words without action is just like living on a deserted island, no point in doing so. That is why we must bring words and actions together to fight discrimination back to where it came from. Words alone would only give a new idea and would not change the world. Action alone would result in only hurting people. Still, words alone, like Martin Luther King or Caesar Chavez, would succeed, but it would take more time and the â€Å"inactive† people would suffer before the world changes. All that is asked is that ideas of how discriminations should be public so that everyone would know how the majority of the population feels and some or even all would change their ideas about how to treat one another and finally achieve equality. It is all about how in which perspective the ideas are seen. It would take a long and grueling process, but the rewards are always better than what is lost.

Relative Rates: Free-Radical Bromination

BroIn this experiment of the relative rates of free-radical chain bromination, we were expected to be able to determine the relative reactivates of the many types of hydrogen atoms involved toward bromine atoms. Bromination is defined to be a regioselective reaction meaning bromine has preference of making or breaking a bond over all other directions that it may have had available.In this case, Markovnikov’s rule is revealed to be the case in this situation that states that adding a protic acid represented as HX to an alkene (sp2 hybridized), the hydrogen from that HX would be attracted to a carbon with the least alkyl groups and the halide (X) would become more attracted and will attach to the carbon containing more alkyl groups. Within the intermediate stage of the bromination reaction, the bromine radical will have already formed and the electronegatively charged radical will have a choice of how to protonate in order to create a stable carbocation.In order to determine the se sp3 hybridized carbons stability, it can be determined by knowing that while comparing, if there are less alkyl groups attached to a carbocation, then there would not be enough electrons to slightly mask over the positive charge on that certain carbocation. Due to this, the more alkyl groups that are attached, the more stable the carbocation would be due to the fact that the electron flow in the electron cloud slightly donates to the carbocation making it almost completely stable.During the experiment, we were expected to organize two groups of tubes with methylene chloride with their respective hydrocarbon (10 drops) as well as the addition of a small amount of bromine. One group of tubes was set in the light and one was set in the dark and when compared, you were already able to see that the ethylbenzene and toluene were the fastest to react in both situations.Due to this fact we can tell since they were the fastest reacting, they can be associated with the fact that they were more than likely secondary and primary benzylic carbons due to their excellent stability and fast reactions. The only other tube that reacted through observation (by eye) by the end of the experiment was the methylcyclohexane; and we could tell that it had slightly reacted by it’s slight orange color, but was not still completely red like the others(sign of bromine).The next most stable carbocation form would be the tertiary aliphatic carbon, so we will infer that this is what has occurred in this case. Due to the fact that methylcyclohexane is sp3 hybridized, we can pin point that our assumption that the bromination is tertiary aliphatic because it is stable with there being three alkyl groups present which means that the electrons within these groups are delocalized and are contained within an orbital that extends over the adjacent atoms involved. The last two tubes to react within the group were cyclohexane and t-butylbenzene in that order.When first added the bromine, the se two were the only ones that seemed to remain red longer and remained the same shade of red even after all of the other tubes had reacted. The reaction of cyclohexane however was expected to react slightly more than the t-butylbenzene due to the fact that the positive charge on the carbocation is delocalized â€Å"better† when there are more alkyl groups involved. This will match up the two with secondary (cyclohexane) and primary aliphatic (t-butylbenzene) bromination.