Fireclay Refractory Bricks...

Fireclay Refractory Bricks  Fireclay refractory bricks are manufactured from unfired refractory bond clay and fireclays (chamotte), fired refractory clay or similar grog materials . Fireclay refractory bricks have two main components namely 18 % to 44 % of alumina (Al2O3) and  50 % to 80 % of silica (SiO2). The variety of clays and manufacturing techniques allows the production of numerous brick types appropriate to particular applications. The usefulness of fireclay refractory bricks are largely due to the presence of mineral mullite, which forms during firing and is characterized by high refractoriness and low thermal expansion. Raw materials for fireclay refractory bricks Refractory fireclay essentially consists of hydrated aluminum silicates with minor proportion of other minerals. The general formula for these aluminum silicates is Al2O3.2SiO2.2H2O, corresponding to 39.5 % alumina, 46.5 % silica, and 14 % water (H2O). Kaolinite is the most common member of this group. At high temperature, the combined water is driven off, and the residue theoretically consists of 45.9 % alumina and 54.1 % silica. However even the purest clays contain small amounts of other constituents , such as compounds of iron, calcium, magnesium, titanium, sodium, potassium, lithium, and usually some free silica. The total quantity of these fluxing agents, which lower the melting point, should be at a level of 5 % to 6 % maximum. TiO2 is not regarded as fluxing agent and was previously counted together with alumina. The name fireclay is given to a group of refractory clays which can generally withstand temperatures above pyrometric cone equivalent (PCE) value of 19. Refractoriness and plasticity are the two main properties needed in fireclay for its suitability in the manufacture of refractory bricks. A good fireclay should have a high fusion point (greater than 1580 deg C) and...

Compensation Management...

Compensation Management The success or failure of an organization hinges on the ability to attract, develop, retain, empower and reward a diverse array of appropriately skilled employees. Compensation is a systematic approach for     providing monetary value to the employees in exchange for work performed by them. It may achieve several purposes such as assisting in recruitment, job performance, and job satisfaction etc. It also supports the achievement of the organizational objectives and is strategic in the sense that it addresses long term issues relating to how employees are to be valued for what they want to achieve. The focus on managing the effectiveness and maximizing the value of employees is a critical management necessity of the present time for the organizational performance. This, in turn, requires a focus on the fundamentals and management of compensation. Managing compensation is not an easy task, since it involves a variety of job categories and goes far beyond just doling out merit pay. It must address the planning for and management of the many categories of variable compensation used in a modern organization to incentivize improved performance of the employees. Compensation management, also known as wage and salary administration, remuneration management, or reward management, is concerned with designing and implementing total compensation package. The traditional concept of wage and salary administration emphasized only on the determination of wage and salary structures in organizational settings. However, over the passage of time, many more forms of compensation entered the field of running an organization and this necessitated to take wage and salary administration in comprehensive way with a suitable change in its nomenclature. Compensation management is based on a well articulated philosophy,  a set of beliefs and guiding principles which are consistent with the values of the organization. It recognizes the...

Design Features of an AC Electric Arc Furnace Feb24

Design Features of an AC Electric Arc Furnace...

Design Features of an AC Electric Arc Furnace  Electric arc furnace (EAF) used for steel making apply high current and low voltage electric energy to the charge materials , and thereby melt and refine them. EAF is a batch furnace which consists of a refractory lined vessel covered with a retractable roof through which electrodes enter the furnace. General features of a typical AC electric arc furnace is shown in Fig 1. Fig 1 General features of an AC electric arc furnace  EAF has a large bowl shaped body with a dish shaped hearth. The shell has a refractory lining inside. The reaction chamber of the furnace is covered from above by a removable roof made of refractory bricks held by a roof ring. It is fed with a three phase alternating current (AC) and has three graphite electrodes which are connected by flexible cables and water cooled copper tubes. The design of electric arc furnaces has changed considerably in recent years. Emphasis has been placed on making furnaces larger, increasing power input rates to the furnace and increasing the speed of furnace movements in order to minimize power off time in furnace operations. Modern steel melting shops with EAFs usually employ a mezzanine furnace installation. In this type of installation, the furnace sits on an upper level above the shop floor. The furnace is supported on a platform which can take on several different configurations. In the half platform configuration, the electrode column support and roof lifting gantry is hinged to the tiltable platform during operation and tapping. When charging the furnace, the complete assembly is lifted and swiveled. This design allows for the shortest electrode arm configuration. In the full platform design, the electrode column support and roof lifting assembly is completely...

Basic Shaped Refractories...

Basic Shaped Refractories  Basic shaped refractories are those refractories which have resistance to corrosive reactions with chemically basic slags, dusts and fumes at elevated temperatures. They are both MgO and CaO based refractories or in combination between them or in combination between MgO and Cr2O3. These refractories belong to MgO- CaO equilibrium system as shown in Fig 1. Fig 1 MgO-CaO equilibrium system  Broadly basic refractories falls into one of the following five compositional categories (Fig 2). Products based on dead burned magnesite (DBM) or magnesia. These products are known as magnesite bricks. Products based on DBM or magnesia in combination with chrome containing materials such as chrome ore. Chrome containing magnesite bricks with about 5 % to 15 % Cr2O3 are known as magnesite chrome bricks while those with 15 % to 30 % chromium are called chrome magnesite bricks. DBM or magnesia in combination with spinel. In these basic bricks magnesia-rich spinel (MgO.Al2O3) replaces chrome ore. These bricks are called magnesite spinel bricks. DBM or magnesia in combination with carbon. These bricks are known as magnesite carbon bricks. Dolomitic products. These bricks are known as sintered dolomite bricks. Fig 2 Categories of basic shaped refractories based on composition  Basic refractories are characterized by an extremely high refractoriness and good resistance to basic slags. Compared to fireclay bricks they do not have glassy phase. These refractories have low resistance both to thermal shocks and creep at temperatures close to 1500 deg C. The chemical-physical characteristics together with a very high thermal capacity and thermal conductivity make basic refractories ideal refractories for steel making processes. Hence basic refractories received increased importance with the introduction of basic oxygen steel making process. One of the more important types of magnesite bricks are those which have low...

Management Control in an Organization...

Management Control in an Organization  Management control in an organization is an approach that enables the organization to produce desired results (generally expressed in terms of performance) by taking actions to achieve those results and by dealing with the dangers brought in by external difficulties (particularly those related to the market, competitors and the economic or political environment) and the internal difficulties of the organization. Management control in the organization consists of a systematic effort on the part of the organizational management. It is required to assure that all organizational resources are being used in the most effective and efficient manner possible in order to achieve the organizational objectives and goals. It constitutes (i) setting of performance standards with planning objectives, (ii) design of information feedback systems, (iii) comparison of actual performance with the predetermined standards, plans or objectives in order to determine whether there are any deviations and to measure their significance, and  (iv) taking of any remedial action if needed. Management control describes the means by which the actions of individuals or groups within the organization are constrained to perform certain actions while avoiding other actions in an effort to achieve organizational objectives and goals. It is not to be seen as an activity of exclusive competence of the administration area , but rather as a process which involves all the functions of the organization, at the appropriate levels of responsibilities. Management control can be defined as the process whereby the organization sets itself performance objectives and strives to achieve them as best it can over time. It is a method for managing the performance of the organization. It is an approach that is pursued over time, both before the action in the planning phase, and after the action in the monitoring...