Theus G.,Metallurgical Engineering Inc.
Advanced Materials and Processes | Year: 2010
The fourth generation of nuclear reactors offers several benefits such as fuel efficiency and cost reduction. Gas-cooled fast reactor (GFR) features a fast-neutron-spectrum, helium-cooled reactor, and a closed fuel cycle, minimize the production of long-lived radioactive waste and make it possible to utilize fissile and fertile materials efficiently. Very-high-temperature reactor is a graphite-moderated, helium-cooled reactor with a thermal neutron spectrum, which offers high-efficiency electricity production and a broad range of process heat applications, while retaining the desirable safety characteristics. Lead-cooled fast reactor features a fast-spectrum lead or lead/bismuth eutectic liquid-metal-cooled reactor and a closed fuel cycle for efficient conversion of fertile uranium and management of actinides. The advantages offered by the reactor including fuel efficiency, its capabilities in nuclear materials management and the reduced production of high-level radioactive waste and actinides.
Park S.S.,Metallurgical Engineering Inc. |
Dyussekenov N.,University of Utah |
Sohn H.Y.,University of Utah
Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science | Year: 2010
The top-blow injection technique of a gas-solid mixture through a circular lance is used in the Mitsubishi Continuous Smelting Process. One of the inherent problems associated with this injection is the severe erosion of the hearth refractory below the lances. A new configuration of the lance to form an annular gas-solid jet rather than a circular jet was designed in the laboratory scale. With this new configuration, solid particles leave the lance at a much lower velocity than the gas, and the penetration behavior of the jet is significantly different than with the circular lance in which the solid particles leave the lance at the same high velocity as the gas. The results of cold model tests using an air-sand jet issuing from a circular lance and an annular lance into a water bath showed that the penetration of the annular jet is much less sensitive to the variations in particle feed rate as well as gas velocity than that of the circular jet. Correlation equations for the penetration depth for both circular and annular jets show agreement among the experimentally obtained values. © The Minerals, Metals & Materials Society and ASM International 2009.
Kaskah S.E.,Metallurgical Engineering Inc.
TMS Annual Meeting | Year: 2013
The Box-Behnken Design (BBD) is used to model the sacrificial Cathodic Protection System (SCPS) to find the factors effectiveness behaviour. For protection potential assessment the BBD receives (resistivity of environment, sacrificial anode alloy, distance between anode and cathode and surface area for the structure to be protected) as input and gives the protection potential as output. By applying BBD with their analysis tools we get many results. The important results which are the factors individual effectiveness on the sacrificial cathodic protection (SCP) process are the resistivity which has the greatest effect on the potential protection (rank=1) followed by sacrificial anode alloy type (rank=2), surface area for structure protected required (rank=3) and distance between anode and cathode (rank=4). The interaction of sacrificial anode alloy and cathode area (χ2χ4) has significant effect on CP process with the limits which are used in this work while the other factors interaction (χ1χ2, χ1χ3, χ1χ4, χ2χ3, χ3χ4) has insignificant effect on the limits which used in this work.
Brocchi E.A.,Metallurgical Engineering Inc. |
S.goncalves M.S.,Pontifical Catholic University of Rio de Janeiro |
Moura F.J.,Metallurgical Engineering Inc.
65th ABM International Congress, 18th IFHTSE Congress and 1st TMS/ABM International Materials Congress 2010 | Year: 2010
The paper describes the preparation of composite Co-ZnO by preferential reduction with hydrogen. Initially we developed a thermodynamic assessment of the main reactions to the process such as pyrolysis of nitrates of cobalt and zinc, responsible for obtaining the respective oxides, and the reduction of hydrogen. The experimental study was performed to evaluate the effect of important variables (temperature and partial pressure of the reacting gas) on the kinetics of reduction reactions. There was the feasibility of establishing conditions occur where the preferential reduction of cobalt oxide in relation to zinc oxide. As an example may be mentioned that in the temperature range of the experiments of reduction of cobalt oxide (590K - 790K) were obtained from 20 conversions and 80% within an interval of time between 1 and 15 minutes using a hydrogen flow of 0.18 L / min. In turn, the composite can be obtained in the test conducted at a temperature of 590K by the time of 30 minutes kept the same flow. The properties of materials were carried out by X-ray diffraction, SEM / EDS and transmission electron microscopy, it is possible to identify relatively pure oxides and Co-ZnO composite very homogeneous and consists of particles on the nanometer scale, these features are desirable for such materials.
Faleiro R.M.R.,Metallurgical Engineering Inc. |
Velloso C.M.,V and M do Brazil |
De Castro L.F.A.,Federal University of Minas Gerais |
Sampaio R.S.,RSConsultants Ltd.
6th Int. Congress on the Science and Technology of Ironmaking 2012, ICSTI 2012 - Including Proceedings from the 42nd Ironmaking and Raw Materials Seminar, and the 13th Brazilian Symp. on Iron Ore | Year: 2012
The need to increase the blast furnaces productivity indexes and to produce hot pig with costs each time lower has led to deep analysis of the factors that affect the cost and the behavior of these reactors. V & M do Brasil is conducting such studies, which have increased since the economic crisis in late 2008, using historical data on raw materials consumption and blast furnaces hot pig production and turning them into information for evaluate the production cost and achieve better planning and economic results for the company. The models developed are based on statistical techniques of Response Surface Models (RSM) and Linear Regression. These models are used strategically to make a cost immediate estimate and the decisions on the offers and opportunities in the market of raw materials for immediate financial return. This work represents a major step in the blast furnaces operation, with a differential for V & M do Brasil, that left to set standard ferrous loads for blast furnaces and started to operate with greater flexibility and variability in the type of load seeks to achieve better economic results.