Properties and Structure of Metallurgical Coke...

Properties and Structure of Metallurgical Coke Metallurgical coke is a porous, fissured, silver-black solid and is an important part of the ironmaking process since it provides the carbon (C) and heat required to chemically reduce iron burden in the blast furnace (BF) to produce hot metal (HM). It is a porous C material with high strength produced by carbonization of coals of specific rank or of coal blends at temperatures around 1100 deg C in coke ovens. It is composed of both the organic and inorganic matter. C is the major component of the organic part. Small amounts of sulphur (S), nitrogen (N2), hydrogen (H2) and oxygen (O2) also occur in the organic part. The inorganic matter in coke is called coke ash (mineral matter) and is typically around 12 % on dry basis. Both the organic and inorganic components influence coke reactivity. Thus, coke characterization is an important aspect to understand the quality of coke formed. The basic understanding of coke quality is an important task as it determines the high temperature and gasification behaviours of coke in the blast furnace (BF). As the coke moves towards the lower zones of BF, it degrades and generates fines, which affects the bed permeability and the process efficiency. Hence, superior coke quality is critical for a stable and efficient BF operation. Coke quality is influenced by many factors such as the rank, the maceral composition (leading to isotropic or anisotropic coke structures), the ash composition and the fluidity of the starting coals, the carbonization conditions including peak temperature, heating rate, particle size, pressure and bulk density as well as heat treatment conditions. The important properties of coke, including mechanical strength and reactivity, are governed by the arrangement of the constituent C atoms. The principal features...

Executives and Effectiveness...

Executives and Effectiveness It is not generally enough for an executive to be intelligent, to work hard or to be knowledgeable for being effective. Effectiveness is something which is different and distinct. But to be effective, the executive does not need special assistances, aptitude, or training. He is required to do certain and fairly simple things. These simple things consist of a few practices which are not inherited. These things are required to be learned. After learning, these things are to be practiced until they become habits. The executive, who works for becoming an effective executive, always succeeds in doing so. Effectiveness can be learned and for an executive to be effective it is necessary that he learns effectiveness. Effectiveness is what executives always need for their performance at work. Without effectiveness there is no performance, no matter how much intelligence and knowledge goes into the work, no matter how many hours it takes. Yet it is perhaps very surprising that very little attention is paid by executives towards effectiveness. In the present day environment, an executive is expected to spend all of his working life in an organization of some kind. His effectiveness depends increasingly on his ability to be effective in the organization, to be effective as an executive and to have abilities to perform. Perhaps even his ability to survive in the organization increasingly depends on how effective executive he is for the organization. As a matter of fact, effectiveness for an executive is a key requirement for his individual achievements and accomplishments. It is the prime requirement for him to carry out his job efficiently. Since he is expected first of all to get the right things done, which simply means that he is expected to be effective. But usually...

Organizational Productivity by Harnessing the Strength...

Organizational Productivity by Harnessing the Strength  Effective organizational management achieves the productivity by harnessing the strengths available in the organization (Fig 1). It is aware that it cannot build on weaknesses. To achieve results, it has to use all types of the available strengths in the organization which include the strengths of the non-executives, the strengths of the executives, and its own strengths. These strengths are the true opportunities. After all, the unique purpose of the organization is to make strength productive. It cannot, of course, overcome the weaknesses with which the organizational employees are generally having with them, but it can always make these weaknesses irrelevant. It is to strive for using the strength of each employee as a building block for the enhancement of the organizational productivity. Fig 1 Organizational productivity by harnessing the strength The major area in which the effective management encounters the challenge of strength is in its function of staffing. The effective management fills positions and promotes people on the basis of what the employee can do. It does not make staffing decisions to minimize the weaknesses of the organization but to maximize the strengths. Such management makes effective appointments since it selects people for their tested abilities and not for the absence of a weakness. It staffs people for their strengths though they may have weaknesses which are to be ignored. The people having narrow but very great strength normally bring success to the organization. If the management tries to place a person or staff the organization to avoid weakness then it ends up at best with mediocrity. The idea that there are ‘well-rounded’ people, people who have only strengths and no weaknesses (whether the term used is the ‘complete man’, ‘mature personality’, ‘well-adjusted personality’, or ‘generalist’)...

Preference of Steel as a Material of Construction...

Preference of Steel as a Material of Construction Steel is one of the most widely used materials, particularly in construction, engineering, white goods, and automobile industries. Steel is also used widely in the manufacture of electrical motors, power generation (nuclear, conventional fuels and wind), power transmission, and railway network. It is also used for gears and engines where it has to be very tough and withstand high temperatures. There is a group of steels known as ‘Advanced High Strength Steels’ (AHSS), which are specially treated steels that can be rolled very thin without losing the element of strength needed for the specific purpose.  These steels are particularly useful for the manufacture of automobiles, helping to reduce the overall mass and thus decrease the consumption of the fuel. Steels with a thin coating of tin are used to make cans for beverages and food. Steels coated in various ways with zinc are used in roofing, for example, and in automobiles as the zinc gives protection to steel against corrosion. It is estimated that there are more than 20,000 million tons of steel in use, which means that there is more than 2 tons of steel is in use for every person living on the Earth. The construction industry is the main user of steel. It uses steel from small buildings to huge bridges and uses it in multiple ways even within a single construction.  A bridge, as an example, may use steel in the huge suspension ropes, the steel plate flooring for the road, the beams for the columns, and for the safety barriers and lighting columns. A large amount of steel is also used in the reinforce concrete. In fact, steel is either used or used to produce all the items needed in our daily life....

Material hardness and hardness testing...

Material hardness and hardness testing Material hardness is the property of the material which enables it to resist plastic deformation, usually by penetration or by indentation. The term of hardness is also referred to stiffness or temper, or to resistance to bending, scratching, abrasion, or cutting. It is the property of a material, which gives it the ability to resist being permanently, deformed when a load is applied. The greater the hardness of the material, the greater the resistance it has to deformation. Hardness has been variously defined as resistance to local penetration, scratching, machining, wear or abrasion, and yielding. The multiplicity of definitions, and corresponding multiplicity of hardness measuring instruments, together with the lack of a fundamental definition, indicates that hardness may not be a fundamental property of a material, but rather a composite one including yield strength, work hardening, true tensile strength, modulus of elasticity, and others. In mineralogy, hardness is normally described as the resistance of a material to being scratched by another material. The ability of materials to resist scratching by another material can be ranked by referring to the Mohs scale which assesses relative hardness of the materials. In metallurgy hardness is defined as the ability of a material to resist plastic deformation. It is sometimes known as indentation hardness which is the resistance of a material to indentation. The usual type of hardness test is where a pointed or rounded indenter is pressed into a surface of the material under a substantially static load. Hardness measurement can be carried out at macro scale, micro scale or nano scale according to the forces applied and displacements obtained. Measurement of the macro hardness of the material is a quick and simple method of finding mechanical property data for the bulk...