Drying Technologies of Lignite Coals Jul20

Drying Technologies of Lignite Coals...

Drying Technologies of Lignite Coals Coals are generally ranked as anthracite, bituminous, sub-bituminous, and lignite, with anthracite being the oldest and lignite the youngest in the age. As coal ages, its moisture content decreases and heating value increases. The lignite coal is often being referred to as brown coal. It is considered to have the lowest rank, lowest carbon (C) content and highest moisture content. Moisture content in lignite coals can be even 60 % or more. Lignite coals are usually shallow buried facilitating its easy open mining. These coals besides high moisture content also have high volatile content and low calorific value (CV) with easy spontaneous ignition. High moisture content is the main restraint for the application of lignite coals. Moisture content of coal causes many difficulties during processing, storage, transport, grinding, and combustion. The high moisture content considerably reduces the CV and combustion efficiency of the coal. It also results into higher heat loss in the exhaust gas. In the combustion of lignite coals, the important part of the energy is consumed to evaporate the moisture inside the coal. The combustion of the high moisture content coal creates several problems such as the additional energy consumption for the moisture evaporation, the insufficient combustion and the additional exhaust discharge etc. Moisture content of the lignite coals can be classified into the following three types. Surface moisture – It is also known as external moisture. The moisture adheres to the surface of coal particulates or in the bigger capillary cavities. It is the moisture, which can be removed by the coal drying in air at ambient temperature (around 25 deg C). It depends on water conditions in deposit. Inherent moisture – It is a naturally combined part of the coal deposit. It is also...

Ferro-Chrome

Ferro-Chrome Ferro-chrome (Fe-Cr) is an alloy comprised of iron (Fe) and chromium (Cr).  Besides Cr and Fe, it also contains varying amounts of carbon (C) and other elements such as silicon (Si), sulphur (S), and phosphorus (P). It is used primarily in the production of stainless steel. The ratio in which the two metals (Fe and Cr) are combined can vary, with the proportion of Cr ranging between 50 % and 70 %. Fe-Cr is frequently classified by the ratio of Cr to C it contains. The vast majority of Fe-Cr produced globally is the ‘charge chrome’. It has a lower Cr to C ratio and is most commonly produced for use in stainless steel production. The charge chrome grade was introduced to differentiate it from the conventional high carbon Fe-Cr (HC Fe-Cr). The second largest produced Fe-Cr ferro-alloy is the HC Fe-Cr which has a higher content of Cr than charge chrome and is being produced from higher grade of the chromite ore. Other grades of Fe-Cr are ‘medium carbon Fe-Cr’ (MC Fe-Cr) and ‘low carbon Fe-C’ (LC Fe-Cr). MC Fe-Cr is also known as intermediate carbon Fe-Cr and can contain upto 4 % of carbon. LC Fe-Cr typically has the Cr content of 60 % minimum with C content ranging from 0.03 % to 0.15 %.  However C content in LC Fe-Cr can be upto 1 %. In international trade, Fe-Cr is classified primarily according to its C content. The common categories of Fe-Cr used in international trade are as follows. Charge chrome with a base of 52 % Cr. HC Fe-Cr with C content ranging from 6 % to 8 %, base of 60 % Cr, and a maximum of 1.5 % Si. HC Fe-Cr with C content ranging from 6...

Influence of stakeholders on the organizational management...

Influence of stakeholders on the organizational management Stakeholders are the people or groups who have an interest, claim, or stake in the organization. Hence, stakeholders usually focus on the performance of the organization and ensure that it remains at an acceptable level. Stakeholders do not have any role in the management of the organization, but they do influence the organizational management. Stakeholders influences the decision making process. They ensure that the organizational work environment remains dynamic, stimulating, and rewarding and there are good working conditions available in the organization so that the organization can perform well. However, it is to be understood that the stakeholders have their own interests which are required to be satisfied by the organization. These interests can vary and can relate to productivity, environment, quality, technology, as well as financial, regulatory, welfare, or ethical issues etc. The organization is required to define, fully understand and address the interests of the stakeholders. This is a very delicate process which is required to be addressed with discretion since it can help the organization to achieve the long term success. The organization which does not have the ability to satisfy its stakeholders defeats the purpose of its existence. For these reasons, management is required to assess the organizational setting and its own role. The major task of the management is to build relationships and to develop a framework for partnership. This framework connects the people of the organization with one another, and with its stakeholders with the stakeholders. For doing it, management is required to identify critical relationship, develop satisfactory working relationships with several key individuals and groups involved, and finally work for the maintenance of these relationships. With the conservation of organizational resources, time, money and personnel as mandate, organizational management seeks to capitalize...

Production of Ferro-Chrome Jul10

Production of Ferro-Chrome...

Production of Ferro-Chrome Ferro-chrome (Fe-Cr) is an alloy comprised of iron (Fe) and chromium (Cr) used primarily in the production of stainless steel. The ratio in which the two metals (Fe and Cr) are combined can vary, with the proportion of Cr ranging between 50 % and 70 %. Fe-Cr is frequently classified by the ratio of Cr to carbon (C) it contains. The vast majority of Fe-Cr produced is the ‘charge chrome’. It has a lower Cr to C ratio and is most commonly produced for use in stainless steel production. The second largest produced Fe-Cr ferro-alloy is the ‘high carbon Fe-Cr (HC Fe-Cr) which has a higher content of Cr and is being produced from higher grade chromite ore. Other grades of Fe-Cr are ‘medium carbon Fe-Cr’ (MC Fe-Cr) and ‘low carbon Fe-C (LC Fe-Cr). MC Fe-Cr is also known as intermediate carbon Fe-Cr and can contain upto 4 % of carbon. LC Fe-Cr typically has the Cr content of minimum 60 % with C content ranging from 0.03 % to 0.15 %.  However C content in LC Fe-Cr can be upto 1 %. Ferro-chrome (Fe-Cr) alloy is essential for the production of stainless steel and special steels which are widely used and are of high quality, typically characterized by a high corrosion resistance and a low tendency to magnetization. The processing cycle of Fe-Cr involves the chemical reduction of the chromite ore. Smelting of HC Fe-Cr ferro-alloy HC Fe-Cr and charge chrome are normally produced by the conventional smelting process utilizing carbo-thermic reduction of chromite ore (consisting oxides of Cr and Fe) using an electric submerged arc furnace (SAF) or a DC (direct current) open arc electric furnace. In SAF, the energy to the furnace is predominantly supplied in a resistive...