Papers by Keyword: Process

Abstract: It was determined that the current method of the Bakalsk mining department siderite ore preparation for blast-furnace smelting does not allow production of concentrate meeting the state-of-the-art metallurgy requirements. The most perspective method is reducing firing when a metallized product with higher iron content is obtained. It was demonstrated that implementation of this method requires the use of a three-zone shaft furnace having the oxidizing roasting zone, the reduction zone and the reduced product cooling zone. Experiments were carried out on the siderite ore reducing firing on laboratory units. The possibility in principle was demonstrated for production of the reduced product with iron content of 60 – 65% from the siderite ore. After the magnetic dressing the concentrate with iron content of 65 – 75% was obtained. It was determined that firing and reduction in hydrogen atmosphere result in the fired product reduction degree of 97 %. The possibility to produce a product suitable for blast-furnace conversion with the reduction degree of about 60% with the use of natural gas air conversion gas was demonstrated. The obtained results were used in the process development for the siderite ore reducing firing in a three-zone shaft furnace.

Abstract: 2116# Rosin Modified Phenolic Resin is synthesized by means of one-step process taking calcium hydroxide as catalyst and Rosin, Bisphenol A, solid formaldehyde and glycerol as main raw materials. The formulation and process are improved and characterized. The result shows that it satisfies technical performance indicators. And, it is preliminarily applied to ink. This resin is expected to be applied to printing ink and coating industry.

Abstract: The huge investment in the airport has great significance for economic development and national defense. In the past 20 years, China has built a large number of airports, and its pavements have been exposed to the outdoor environment for a long time, resulting in easy be damaged. Therefore, in recent years, the problems faced by the renovation of airport pavements have become increasingly prominent. Based on the analysis of the core functional indicators of the airport pavement, the paper establishes the hierarchical structure model, functional model and cost model, and finally forms the optimization model of the renovation process decision. The simulation calculation is carried out through engineering examples, and the advantages, shortcomings and their gaps of different renovation processes are obtained, which prove the rationality and effectiveness of the model.

Abstract: Electrochemical techniques can be used in the various fields, such as anodization, deposition, etching, polishing, pitting, and corrosion applications. In this paper, we focus on the high quality coloring anodic film fabrication. In the prior technologies, anodization generally has the main purpose of surface decoration or corrosion resistance. However, in the high technologies, the characteristics of film thickness, anti-voltage value, surface roughness, surface color and hardness of the anodic film have been strict requirements. The key parameters of anodization such as, electrolyte composition, current-voltage curve pattern, temperature, current density, time, final voltage, efficiency, and electricity affect the quality of anodic film. In order to make a high quality anodic film, this paper provided a detail anodization process and discussed the quality of anodic film.

Abstract: Every organisation is a very complex system. It consists of soft and hard parts of a system. Their relationships and the influence of the substantial neighbourhood lead to the development of a number of problems. This article deals with nonconformities in the relationship to material aspects in management systems of organisations. Nonconformities were found from the survey which was conducted in organisations in a one region of the Czech Republic. There are from production, maintenance, store, quality department and so on. The article classifies nonconformities by a type, by a severity and by an amount. It describes the relation to risks of the management system and also to main and minor processes and to innovations. In conclusion, the article presents some recommendations for the increase of quality of a production and also for the simplification of the management system.

Abstract: In this paper the new method of forming based on flanging is investigated. The obtained experimental results supported the theoretical conclusions and allowed us to define geometric dimensions of a blank for forming the thin axisymmetric parts with minimal thickness fluctuations. This analysis serves as a foundation for further design of the technological process.

Abstract: We have studied the influence of oxidation-reduction reactions on the structure and strength behavior of the Kachkanar fluxed pellets both in their initial condition and during reduction. It has been discovered that at heating rates and temperatures found in industrial units the roasted pellets that are not oxidized to a full extent and are characterized by zonal structure do not meet the requirements imposed for the blast-furnace smelting raw materials. To develop a process that would ensure high metallurgical properties, we have analyzed the hematite dissociation reaction. It was found that the temperature and the content of slag-forming oxides influence this reaction. A sinter pot was used to carry out the research and determine metallurgical properties of partially dissociated pellets. The obtained results helped to develop a process to dissociate hematite at lower temperatures with calcium ferrosilicate melt. Such pellets are reduced at the temperatures of over 700^оС, which prevents their destruction in blast furnaces.

Abstract: The search for effective methods of management is one of the strategic directions of economic development. To obtain high-quality products, organizations should manage nonconformities and causes of product defects. The paper focuses on the analysis of groups of defects of welded joints using statistical methods. Welding process was considered as one of the processes of management. The possible causes of nonconformities were indicated. The method of failure modes and effects analysis was used to quantify the level of risk. A matrix of consequences and probabilities was presented, and critical risks and risk situations were selected. The proposed measures to eliminate or minimize negative effects enable identification of problem areas of the life cycle of welded structures.

Abstract: We have developed the process that enables receiving pellets from zinc-containing dust and recovering them in a Waelz kiln with practically total zinc distillation and its capture in bag filters. As this takes place, metallic iron, still present in the pellets, can be used in metallurgical treatment. We have elaborated the process instructions to obtain pellets from zinc-containing dust with an addition of solid fuel, magnesite, and bentonite. To simulate recovery of the carbon-containing pellets in production, bench tests have been performed. These allowed us to determine principal operating conditions of the technological procedure of metallurgical zinc-containing dust recovery and validate the unit for recovery of this dust. The data obtained from the production tests prove feasibility of implementation of this process and allow assessing economic efficiency of zinc-containing dust recovery.

Abstract: A lap welding experiment of DP590 steel and 6061 aluminum plate is carried out by using Heating Friction Stir Spot Welding (HFSSW) to study the influence of welding parameters on the forming quality. The results show that a lap joint with better forming can be obtained for the dissimilar metal of steel and aluminum. Under the condition that the rotating speed of the stirring tool is 1000r/min, the penetration depth, 0.2mm, the dwell time, 90s, the welding pressure, 0.2Mp, and the flow rate of cooling air, 20L/min, the forming quality of the surface of the joint line is good & bright, and the exit hole is also smaller. The mechanism of heat production is revealed in the following: the main heat is produced by the friction between the stirring tool shoulder and the welded part & between the probe and the welded part as well as by the latent heat resulted from the plastic deformation of the material in joint line during welding.