Understanding Pellets and Pellet Plant Operations Mar21

Understanding Pellets and Pellet Plant Operations...

Understanding Pellets and Pellet Plant Operations Pelletizing is an agglomeration process which converts very fine grained iron ore into balls of a certain diameter range (normally 8mm to 20 mm, also known as pellets. These pellets are suitable for blast furnace and direct reduction processes. Pelletizing differs from sintering in that a green unbaked pellet or ball is formed and then hardened by heating. Iron ore pellets  can be made from beneficiated or run of mine iron ore fines. Lean iron ores are normally upgraded to a higher iron ore content through beneficiation.  This process generates iron ore filter cake which needs to be pelletized so that it can be used in an iron making process.  Also during the processing of high grade iron ores which do not need beneficiation, generated fines can be pelletized and used instead of being disposed of. Pellet plants can be located at mines, near ports or can be attached to steel plants. Equipped with advanced environmental technology, they are virtually pollution free, generating no solid or liquid residues. History of pelletization The history of pellets began in 1912 when A.G.Andersson, a Swede, invented a pelletizing method. The commercial use of pellets, however, began in the USA after World War. Various studies were conducted in USA with the aim of developing the vast reserves of taconite (a low grade iron ore) in the area around the Great Lakes. The process of enriching taconite ore involved grinding the ore to remove gangues and upgrading the iron ore (i.e., an ore beneficiation process). The resultant high grade ore is in the form of fine particles, as small as 0.1 mm or less, which are not suitable for sintering. This issue led to the development of the pelletizing process. In 1943, Dr. Davis,...

International Commercial Terms...

International Commercial Terms Incoterms®  is an abbreviation for the international commercial terms and is the registered trademark name given to these terms by International Chamber of Commerce (ICC). They are a  series of three-letter trade terms related to common contractual sales practices. The Incoterms® rules are intended primarily to clearly communicate the tasks, costs, and risks associated with the transportation and delivery of goods. They are published by the ICC and are widely used in international commercial transactions. Incoterms® are a set of rules which define the responsibilities of sellers and buyers for the delivery of goods under sales contracts for domestic and international trade. They apportion transportation costs and responsibilities associated with the delivery of goods between buyers (importers) and sellers (exporters) and reflect modern day transportation practices. Incoterms® significantly reduce misunderstandings among trading parties and thereby minimize trade disputes and litigation. The Incoterms® was first conceived by ICC in 1921, and brought to fruition with the first Incoterms® rules in 1936. The Incoterms® were created with the purpose of providing a set of international rules for the interpretation of the most commonly used trade terms in foreign trade. A Trade Terms Committee with the assistance of the ICC National Committees developed the first six rules in 1923 namely FOB, FAS, FOT, FOR, Free Delivered CIF and C&F, which were the precursor of what would later be known as the Incoterms® rules. This set in motion a long and vibrant history of Incoterms® rules. As commercial practices, types of goods and transports, and international laws evolve, the Incoterms ® rules need to be regularly updated by experienced international experts. Since the issue of first set of rules in 1936, ICC expert lawyers and trade practitioners have updated them six times to keep pace...

Purchase Management

Purchase Management  Materials today are lifeblood of industry. They must be available at the proper time, in the proper quantity , at the proper place, and at the proper price. Purchasing is the function of buying materials and services from external sources in an organization. It is one of  the most critical functions as it provides the input materials to the organization for converting it into output products. Purchase management is the management of the purchase and procurement process and related aspects in the organization. Purchase department buys raw materials, equipment, spare parts, consumables, and services etc. as required by the organization and hence purchase department has a very important role in the functioning of the organization. Purchase activity is one of the most crucial activity in the organization and needs an effective management. It is the main activity in the area of material management. Often procurement and purchasing are used as synonym to each other. Procurement is used to define one of several supply functions involved in logistics activities. In the broadest sense procurement includes the entire process by which all classes of resources (people, materials, facilities and services) for the organization are obtained. Since purchasing is a unique function, it differs a bit from procurement in the sense that while procurement, with the same objective has a wider domain , purchasing with the same objective is included in it. In a manufacturing  organization, purchase is the first element which affects the product cost and hence has a big impact on the organizational profit. The organization needs an efficient and economic purchasing and procurement of its various supplies of materials from the suppliers. The purchase department which performs the function of purchasing and procurement of the materials is to function very efficiently. Purchasing is no doubt a vast and complex...

Understanding Sinter and Sinter Plant Operations Mar15

Understanding Sinter and Sinter Plant Operations...

Understanding Sinter and Sinter Plant Operations               Sintering is a process of agglomeration of fine mineral particles into a porous and lumpy mass by incipient fusion caused by heat produced by combustion of solid fuel within the mass itself. The sintering process is a pre-treatment step in the production of iron, where fine particles of iron ores and also secondary iron oxide wastes (collected dusts, mill scale etc.) along with fluxes (lime, limestone and dolomite) are agglomerated by combustion.  Agglomeration of the fines is necessary to enable the passage of hot gases during the blast furnace operation. Sintering has been referred to as the art of burning a fuel mixed with ore under controlled conditions. It involves the heating of fine iron ore with flux and coke fines or coal to produce a semi-molten mass that solidifies into porous pieces of sinter with the size and strength characteristics necessary for feeding into the blast furnace. Although simple in principle, sintering plant requires that a number of important factors in its design and operation be observed to attain optimum performance. A simplified schematic flow diagram of sintering process is at Fig 1.  Fig 1 Simplified flow diagram of a sintering process  There are basically the following three types of sinters. Non flux or acid sinters – In these sinters no flux is added to the iron ore in preparing the sinter mix. Non flux sinters are very rarely being produced these days. Self fluxing or basic sinters – These are the sinters where sufficient flux is added in the sinter mix for producing slags of desired basicity (CaO/SiO2) in blast furnace taking into account the acidic oxides in the blast furnace burden. Super flux sinters – These are the sinters where sufficient flux is added in...

Carbon Based Refractories...

Carbon Based Refractories Carbon based refractories behave differently than the typical ceramic refractories, primarily because carbon based refractories are conductive rather than insulating. All carbon based refractory lining systems perform as a ‘conductive cooling system’ as opposed to a classic definition of a refractory lining that is typically an ‘insulating system’. Consequently, proper cooling must always be utilized with any carbon based refractory lining system to assist in maintaining refractory temperatures that are below the critical chemical attack temperature for mechanisms such as oxidation, alkali, CO degradation, or dissolution of the carbon by liquid metal. The words ‘carbon’ and ‘graphite’ are often used inter-changeably, but the two are not synonymous. Additionally, the words ‘semi-graphite’ and ‘semi-graphitic’ are also similarly misused. Carbon based refractories are basically classified  in three categories namely (i) carbon refractories, (ii) carbon containing basic refractories, and (iii) carbon containing non basic refractories. (Fig 1) Fig 1 Carbon based refractories  Within the area of carbon based refractories, phenol-formaldehyde (Phenolic) resins have found a multitude of uses. One significant attribute of phenolic resins is their ability to form a carbon bond. This, to a large extent, contributed to their initial use in this Industry, as cleaner alternatives to the traditional pitch and tar binders. Also as the industry increased usage of carbon bonded products, phenolic resin bonded products have replaced more and more the traditional ceramic bond in many areas of liquid metal contact. Phenolic resins can also dramatically improve production rates and consistency of refractories. Their low temperature curing characteristics give dimensional stability, and in many applications, the final heating of the product to form the carbon bond, can be carried after the product has been installed at the customer.  They have excellent compatibility with many refractory raw materials, and give good...