Ferro-Silicon

Ferro-Silicon Ferro-silicon (Fe-Si) is a metallic ferro-alloy having iron (Fe) and silicon (Si) as its main elements. In commercial terminology It is defined as a ferro-alloy containing 4 % or more of Fe, more than 8 % but not more than 96 % of Si, 3 % or less phosphorus (P), 30 % or less of manganese (Mn), less than 3 % of magnesium (Mg), and 10 % or less any other element. However, the regular grades of the ferro-alloy normally contain Si in the range of 15 % to 90 %. The usual Si contents in the Fe-Si available in the market are 15 %, 45 %, 65 %, 75 %, and 90 %. The remainder is Fe and minor elements. The minor elements, such as aluminum (Al), calcium (Ca), carbon (C), manganese (Mn), phosphorus (P), and sulphur (S) are present in small percentages in Fe-Si. Commercially, Fe-Si is differentiated by its grade and size. Fe-Si grades are defined by the percentages of Si and minor elements contained in the product. The principal characteristic is the percentage of Si contained in the ferro-alloy and the grades are referred to primarily by reference to that percentage. Hence 75 % Fe-Si contains around 75 % of Si in it. Fe-Si grades are further defined by the percentages of minor elements present in the product. ‘Regular grade 75 % Fe-Si’ denote that the product containing the indicated percentages of Si and recognized maximum percentages of minor elements. Other grades of Fe-Si differ from regular grades by having more restrictive limits on the content of elements such as Al, titanium (Ti), and/or Ca in the ferro-alloy. Fe-Si is also produced in a grade that contains controlled amounts of minor elements for the purpose of adding them to...

Factors influencing the cost of an item...

Factors influencing the cost of an item The term ‘item’ here can be multi-component equipment, a unit consisting of several equipments, or a project. The term ‘cost’ here means the total amount which the purchaser spends for the procurement of the item. The cost includes the amount paid to the seller through the contract entered with him and the additional expenditure incurred by the purchaser outside the contract for the procurement of the item. The contractual price is the amount which the purchaser pays to the supplier for fulfilling his obligations under the contract. While entering into a contract between the purchaser and the seller, the purchaser wants to pay the minimum price to keep his cost under control while the seller wants a price which can give him a decent profit after taking care of all the expenditure which he has to incur for the production and selling of the item. Often it may appear that the purchaser is paying a higher/lower price to the seller when compared to the price paid by another purchaser for the same item. This type of comparison is not advisable though very frequently it is being done by the purchasers, auditors and many other peoples.  In two contacts of purchase/sale of the same base item, though the supply of the base equipment can remain the same in the two contracts still the terms and conditions of the contract can differ a lot between the two contracts to influence the contractual price. For understanding the reasons for the difference in the price paid by the two purchasers for the so called same base item, it is necessary to understand the factors which are influencing the cost. These factors are (i) base date of the contract, (ii) scope of...

Production of Ferro-Silicon Jun27

Production of Ferro-Silicon...

Production of Ferro-Silicon Ferro-silicon (Fe-Si) is a ferro-alloy having iron (Fe) and silicon (Si) as its main elements. The ferro-alloy normally contains Si in the range of 15 % to 90 %. The usual Si contents in the Fe-Si available in the market are 15 %, 45 %, 65 %, 75 %, and 90 %. The remainder is Fe, with around 2 % of other elements like aluminum (Al) and calcium (Ca). Fe-Si is produced industrially by carbo-thermic reduction of silicon dioxide (SiO2) with carbon (C) in the presence of iron ore, scrap iron, mill scale, or other source of iron. The smelting of Fe-Si is a continuous process carried out in the electric submerged arc furnace (SAF) with the self-baking electrodes. Fe-Si (typical qualities 65%, 75% and 90% silicon) is mainly used during steelmaking and in foundries for the production of C steels, stainless steels as a deoxidizing agent and for the alloying of steel and cast iron. It is also used for the production of silicon steel also called electrical steel. During the production of cast iron, Fe-Si is also used for inoculation of the iron to accelerate graphitization. In arc welding Fe-Si can be found in some electrode coatings. The ideal reduction reaction during the production of Fe-Si silicon is SiO2+2C=Si+2CO. However the real reaction is quite complex due to the different temperature zones inside the SAF. The gas in the hottest zone has a high content of silicon mono oxide (SiO) which is required to be recovered in the outer charge layers if the recovery of Si is to be high. The recovery reactions occur in the outer charge layers where they heat the charge to a very high temperature. The outlet gas form the furnace contains SiO2 which can...

Ferro-Manganese

Ferro-Manganese Ferro-manganese (Fe-Mn) is a metallic ferro alloy which is added usually along with ferro-silicon (Fe-Si) as ladle addition during steelmaking. It is a ferroalloy composed principally of manganese (Mn) and iron (Fe), and normally contains much smaller proportions of minor elements, such as carbon (C), phosphorus (P), and sulphur (S). Fe-Mn is an important additive used as a deoxidizer in the production of steel. It is a master alloy of Fe and Mn with a minimum Mn content of 65 %, and maximum Mn content of 95 %. There are two families of Mn alloys. One is called Fe-Mn while the other is known as silico-manganese (Si-Mn). Around 93 % of all the Mn produced is in the form of Mn ferroalloys consists of the Fe-Mn grades and the Si-Mn grades. Mn plays an important role in the manufacturing of steel as deoxidizing, desulphurizing, and alloying agent. It is a mild deoxidizer than silicon (Si) but enhances the effectiveness of the latter due to the formation of stable manganese silicates and aluminates. Mn is used as an alloying element in almost all types of steel. Of particular interest is its modifying effect on the iron-carbon (Fe-C) system by increasing the hardenability of the steel. Fe-Mn is produced in a number of grades and sizes and is consumed in bulk form primarily in the production of steel as a source of Mn, although some Fe-Mn is also used as an alloying agent in the production of iron castings. Mn, which is intentionally present in nearly all steels, is used as a steel desulphurizer and deoxidizer. Mn improves the tensile strength, workability, toughness, hardness and resistance to abrasion. By removing S from steel, Mn prevents the steel from becoming brittle during the hot rolling process....

Understanding the Organization...

Understanding the Organization An organization consists of a system where two or more people work together to achieve a group result. In the organization organized human activities take place. These human activities are the co-operative activities of two or more persons. The organization is the process of dividing up of these activities into various tasks to be performed and the coordination of these tasks to accomplish the activities. The structure of an organization can be defined simply as the sum total of the ways in which it divides its activities into distinct tasks and then achieves coordination among them. An organization is a basic social unit which is generally established for the purpose of achieving the set objectives. The organization is considered to have several distinct features. These features can be (i) a common objectives or an accepted pattern of purpose, (ii) a set of shared values or common beliefs which provide individuals a sense of identification and belonging, (iii) a continuity of goal oriented interaction, (iv) a division of work purposely planned for achievement of the objectives, and (v) a system of authority or a chain of command to achieve conscious coordination of efforts for achieving the objectives. Organizations can be either informal or formal. An informal organization can be characterized by some of the features of the formal organization, but it lacks one or more of these features. Individuals who share a common value may meet regularly to foster some objectives, and this group can become a recognizable formal organization. Some informal groups never develop the consistent characteristics of a formal organization, however, and simply remain informal. Formal organizations almost inevitably give rise to informal organizations. Such informal groups can be regarded as spontaneous organizations which emerge since individuals are brought together...