Induction Furnace Refractory Lining with Silica Ramming Mass...

Induction Furnace Refractory Lining with Silica Ramming Mass Induction furnaces are used for melting cast iron, mild steel and various alloy steels in foundries and making of steel in mini steel plants using sponge iron. Lining is the important part of induction furnace. Furnace performance is directly related to the performance of its lining. Well laid and stabilized lining results in smooth working of furnace, optimum output, and good control of the metallurgical reactions. The lining practice best suited to a particular furnace depends upon the capacity and design of the furnace, operation practice adopted during making of a heat, and furnace output. For successful and consistent performance of the lining, the important aspects are (i) use of proper grade and quality of the lining material, (ii) careful and systematic lining practice, and (iii) consistency in working conditions.  Fig 1 shows the installed refractory lining of a coreless induction furnace, Fig 1 Installed refractory lining of a coreless induction furnace The characteristics of the lining material needed for consistent lining life include (i) thermal characteristics which means that it has to withstand the stresses developed by thermal cycles during the furnace operation, (ii) chemically inert to metal being melted, (iii) structural strength under operating conditions, (iv) high erosion resistance, (v) ease of installation, (vi) reparability of the lining, (vii) ease of dismantling, and (viii) economics. As such, it is very difficult to judge the suitability of a particular lining under various conditions like operating temperature, metal being melted, the type of formed slag, and furnace capacity. Chemical inertness to the liquid metal can be achieved by using acid and neutral lining for the acidic slag and neutral or basic lining for the basic slags. Normally, the selection of refractory for the furnace lining is...

Management of the Process Productivity...

Management of the Process Productivity A process can be defined as a set of horizontal sequence of interrelated or interacting activities, which transforms inputs (needs) into outputs (results) for meeting the needs of customers or stakeholders. Inputs and intended outputs of a process can be tangible (such as equipment, materials or components) or intangible (such as energy or information). Outputs can also be unintended, such as waste or pollution.  The process needs a resource that provides the needed energy to the process for the transformation from the input to output to occur. Each process has customers and other interested parties (who may be either internal or external to the organization), with needs and expectations about the process, who define the required outputs of the process. A process is an interacting combination at any level of complexity, of people, materials, tools, machines, automation, software facilities, and procedures designed to work together for the common purpose of producing product of that quality which is needed by the customer. The process is central to the production system in the organization (Fig 1). The process instills quality in the product. Fig 1 Process of a production system The objectives of a process are normally (i) low cost operation, (ii) high performance, (iii) consistent product quality, (iv) high productivity level, (v) high yield, and (vi) product customization. An organization to function has several processes. The organization can reach its goals and objectives in an efficient and effective manner only if all the processes operate at a high level of productivity. Productivity is the quality or state of being productive. It is the measure of how specified resources are managed to accomplish timely objectives stated in terms of quality and quantity. It indicates how well the resources such as materials,...

Redsmelt process for ironmaking Apr19

Redsmelt process for ironmaking...

Redsmelt process for ironmaking Redsmelt is a new ironmaking process based a two reduction steps. These are (i) pre-reduction of iron bearing materials in a rotary hearth furnace (RHF), and (ii) smelting of the hot pre-reduced iron (DRI, direct reduced iron). Originally a submerged arc furnace (SAF) has been used for the second step. SAF has now been replaced by a coal and oxygen blown converter (oxy-coal reactor) known as ‘New Smelting Technology’ (NST). The RHF reduces green pellets made out of iron ore, reductant fines and binders to produce hot, metallized DRI which is charged to the NST for its smelting to hot metal. Redsmelt process has been conceived to be consisting of a cost-effective and environmental-friendly technology. The important highlights of the process are as follows. The process does not need any prepared charge materials The process does not need electrical energy, since the DRI smelting is carried out using chemical energy The smelter is having high productivity resulting into limited investment cost The process can use practically all the residues generated during various processes of the steel plant (including sludges and oily mill scales), thus it solves the increasing issue of steel wastes treatment The off-gas coming from the smelting reactor is used as a fuel in the RHF, with optimization of the overall energy utilization. This results into effective reduction in energy consumption A Redsmelt demonstration plant with two step smelting reduction process was built and tested in Piombino works (Italy) for the production of hot metal. The demonstration plant was commissioned in the year 2003. The two production steps in the demonstration plant have been based upon pre-reduction of iron-bearing materials in a RHF and smelting of the hot DRI in an oxy-coal converter. The plant has been designed...

Iron Carbide

Iron Carbide Iron carbide is a high melting point, non-pyrophoric, strongly magnetic synthetic compound obtained in granular or powder form. It is composed of three atoms of Fe and one atom C and its chemical formula is Fe3C. The commercial iron carbide consists of around 90 % total iron and around 6 % to 6.5 % of total carbon. The primary use of the product is as a metallic charge during steelmaking for substitution of hot metal, direct reduced iron, or steel scrap. Iron carbide is an intermetallic compound of iron and carbon. It is, more precisely, intermediate transition metal carbide. Its stoichiometric composition consists of 6.67 % carbon and 93.3 % iron (Fe) by weight. It has an orthorhombic crystal structure (Fig 1). It is a hard, brittle material and normally classified as a ceramic in its pure form. It is a frequently found and important constituent in ferrous metallurgy. While iron carbide is present in most steels and cast irons, it is produced as a raw material by the iron carbide process, which belongs to the family of alternative ironmaking technologies. Fig 1 Crystal of iron carbide Iron carbide is a premium quality feed for steelmaking in electric arc furnaces and basic oxygen furnaces. It is available as dark gray granules or powder. It offers matchless metallurgical advantages and outstanding cost savings. It has a density of 7.64 kg/cu m and is thus slightly denser than the liquid iron, which has a density of 6.98 kg/cu m. The iron carbide is composed of three atoms of Fe and one atom C and is also known as cementite. Cementite is an intermetallic compound which is hard, brittle, and metastable because it tends to decompose in ferrite (or austenite) and graphite according to the reaction Fe3C = 3 Fe + C. In fact, this transformation is not...

Competencies and development of competency framework for organization...

Competencies and development of competency framework for organization The greatest strength of an organization, and the key to its success, is the quality of its employees and their ability to thrive and fulfill their potential while delivering the output expected from them. The competency framework enables the organization to clarify expectations and to set standards for performance throughout the organization. It is a guide to help management and the employees to understand the behaviours and skills expected of them and what they are to strive for achieving them. The concept of competencies emerged during the early 1980s as a response to the organizational changes. This concept drives the organization towards higher performance levels. During the subsequent decades, competency frameworks have become an increasingly accepted part of modern HR (human resource) practice in the organizations. Competencies A competency is considered to be a cluster of related knowledge, skills, abilities, and characteristics which are related to the performance of a significant aspect of the practice of a profession. The term ‘competency’ is usually defined as a combination of skills, attributes and behaviours which are directly related to the performance on the job. They are important for all the employees regardless of occupation, function, or level. Competencies normally focus on the personal attributes or inputs of employees in the organization. They are the behaviours (and technical attributes where appropriate) which employees are to have, or are to acquire, for their effective performance at work. Competencies are broader concepts which encompass demonstrable performance outputs as well as behaviour inputs, and relate to a system or set of minimum standards required for the performance at the work. Competencies are means to provide organizational focus, as building blocks for human resource systems, and as methods for certifying attainment of various...