Blast Furnace Stock House Jun12

Blast Furnace Stock House...

Blast Furnace Stock House  A blast furnace (BF) needs for the production of hot metal (HM) (i) iron bearing raw materials like sinter, pellet, and calibrated lump ore also known as sized iron ore, (ii) fuels and reductant like BF coke, nut coke and pulverized coal, (iii) fluxing materials like lime stone, dolomite, and quartzite, and (iv) miscellaneous materials (also known as ‘additives’) like manganese ore, and titani-ferrous iron ore etc. All these materials except the pulverized coal which is injected in the blast furnace at the tuyere level are charged in the furnace at the top and are handled through a stock house. The blast furnace charging system consists of two main areas, the stock house system and the top charging equipment. The purpose of the blast furnace charging system is to enable the raw materials to be placed inside the furnace accurately and consistently in a predictable and controlled way. At the stock house system, the weighing, batching of the raw materials is carried out for their delivery to the top charging equipment. The top charging equipment serves the function of delivering blast furnace raw materials to the furnace top and distributing these materials into the furnace. The purpose of the stock house is to deliver the correct quantities of coke, iron bearing materials, fluxing materials and additives to the furnace as expeditiously as possible to keep the blast furnace at top operating performance. The stock house is the area where the individual raw material types are stored and then measured out in the prescribed order for delivery to the top of the blast furnace. The typical blast furnace stock house in the early 1900s was built as a deep pit in the ground and rail cars were moved over it and...

Screening of Materials and Types of Screens...

Screening of Materials and Types of Screens Size control is done (i) to prevent undersize in the feed from blocking the next size reduction stage (scalping), (ii) to prevent oversize from moving into the next size reduction or operation stage (circuit sizing), and (iii) to prepare a sized product (product sizing). There are two methods dominating size control processes. They are (i) screening using a geometrical pattern for size control, and (ii) classification using particle motion for size control. Screening using geometrical patterns for size control (Fig 1) makes use of screening media made of bars, wires, and panels with holes usually rounds, squares, rectangle aligned to length and rectangle aligned to width. Fig 1 Geometrical patterns for the size control Screening is the process of separating solids into two or more products on basis of their size. The objective of screening is size control. The purpose of screening is to separate from a granular substance particles that are smaller than the screen opening from those that are larger. This is not as simple as it sounds, and the difficulties compound as the opening becomes smaller. This can be done dry or wet. Action of screening is aided when screen is subjected to some kind of motion, reciprocating or gyratory in the horizontal plane, or shaken with a reciprocating motion having both vertical and horizontal components. The minus particles pass through the screen at a diminishing rate until all but the particles closest to the opening size have been separated out. The time duration of the shaking to reach this stage is roughly proportional to the amount of the material on the screen. The performance of screens falls back on three main parameters namely (i) motion, (ii) inclination, and (iii) screening media. It is...