Browsing by Subject "Usim Pac"

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    Development of a Mathematical Model for Fine Screening
    (University of Minnesota Duluth, 2004-04-16) Pletka, Jeremy
    Usim Pac mineral processing plant simulation software is used by the University of Minnesota's Coleraine Minerals Research Laboratory Concentrator Modeling Center to simulate taconite plant operations. Its ability to simulate fine screening is limited, since the present suitable models assume a constant partition curve for a given set of screens and do not account for changes in operating conditions. As it is well known that the fine screen unit operation is sensitive to operating conditions such as feed density, loading, and size, it becomes clear that for accurate simulations, the model will require modifications. Consequently, a series of tests was performed on a pilot scale unit where several of the operating conditions were varied. Partition curve parameters were then related to operating conditions for relevant mineral components.
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    Iron Ore Processing Improvements through Process Modeling and Computer Simulation
    (University of Minnesota Duluth, 2001-06-15) Ersayin, Salih
    In 1997, under the auspices of the Iron Ore Cooperative Research Program, iron ore mining companies operating on the Iron Range decided to work as a consortium in establishing expertise in the development of math models of individual taconite concentration operations and their use to simulate portions of the integrated concentration process. This led to the establishment in 1998 of the Concentrator Modeling Center within the Coleraine Minerals Research Laboratory (CMRL) of the University of Minnesota - Duluth. Following discussions on the type of software to be used by the Center, Usim Pac, mineral processing software developed by BRGM of France was selected due to the availability of a larger number of models, and model incorporation capability to add those to be developed in the future. The Center became fully operational when Dr. Salih Ersayin started to work as the program director on Nov. 1, 1999. While the application of modeling and simulation has provided significant benefits in the processing of base metal ores, its application to the processing of magnetic taconite has been hindered. This was caused by the need to incorporate the modeling of mineral liberation into the comminution models for size reduction steps, which occur between several stages of magnetic separation. An initial effort at integrating the modeling of size reduction, mineral liberation was carried out by Wiegel1 for the Erie Mining Company process in 1976. Plant scale implementation of the combined use process modeling and plant testing was reported for the National Steel Company secondary grinding section modifications 2 . Recently, Schneider 3 developed a mineral liberation model based on liberation characterization by scanning electron microscopy measurements. He validated his model using plant data obtained from the Fairlane Plant of Eveleth Taconite. For simulation purposes, he integrated his liberation approach into a ball mill grinding model. He also presented magnetic separator and hydrocyclone model structures compatible with the type of data produced by the liberation model. Despite of these developments, there still was a need to develop a simplified approach to the integrated size reduction/liberation model for taconite processing, models for magnetic separators, hydroseparators and fine screens, which would take into account the significant operating and design parameters. Therefore, the initial efforts of the Center were concentrated on development of simplified integrated mineral liberation/size reduction and magnetic separator models using funds allocated by the Permanent University Trust Fund (PUF), while providing a simulation service to taconite plant operators with the available software. Data from four plants in the Range taken as a part of an earlier Iron Ore Coop project was analyzed using the existing capabilities of the software. The data was first mass balanced and performance of individual pieces of equipment was examined. Results were presented to the plant engineers; their implications and potential improvements were discussed. To illustrate the capabilities of the software and potential benefits from the use of simulation, some modifications in plant flow sheets and operating/design conditions were simulated using the same data as a basis. These simulation results were also presented to the relevant engineers.
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    Iron Ore Processing Improvements through Process Modeling and Computer Simulation - 2003
    (University of Minnesota Duluth, 2003-09-05) Ersayin, Salih
    When the Concentrator Modeling Center was established in 1998, its first task was to define the prevailing conditions in terms of taconite plant simulation. Capabilities of existing software and unit operations needing improved models were defined. Preliminary simulations were carried out to determine how accurately the existing models could simulate taconite plant operations. Plant data was analyzed to determine how taconite plant operation could be simulated and to define the common problems and bottlenecks. It also provided some insight in terms of model development. This work indicated that there was a need for improved model development for the unit operations commonly used in taconite processing. Therefore, the Center's task was defined as "to develop advanced models, while providing simulation based assistance to the taconite plant operators using available simulation capabilities. n On the model development side, the specific objective was to develop improved models for magnetic separators, hydroseparators, fine screens and mineral liberation. Despite unsuccessful attempts to obtain federal funding for this type of work due to unwillingness of federal sources to fund projects that would benefit only a smaller section of the mining industry, the Center managed to improve the very simple models available for these unit operations using its plant database and limited funding for specific projects, Now it has the capability of simulating taconite processing more realistically. This was achieved . by analyzing available plant data and developing theoretical understanding of how these unit operations function, and along with pilot scale testing in the case of fine screen modeling. The Center's task was not only to develop these models, but also to incorporate them into the existing software, Usim Pac. Models for magnetic separators and hydroseparators were converted to the programming language of the software. The liberation model is expected to be incorporated soon. The Center's simulation efforts were concentrated on case studies involving the Evtac and lspat Inland plants. While replacing hydrocyclones in a ball mill grinding circuit with fine screens was the focus of study in the former plant, improving overall plant performance was the aim in the latter, which is still an on-going project funded by the DOE. Another simulation study was carried out to determine benefits of ore segregation in one of the taconite plants.