Browsing by Subject "Ispat Inland"

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    Concentrator Modeling Database Development and Simulation of Ispat Inland Plant
    (University of Minnesota Duluth, 2003-09-05) Ersayin, Salih
    The Ispat Inland plant processes two blends of ore during different time periods throughout the year. Although these two blends have mineralogical differences, they go through the same process. The major difference in the process becomes fineness of grind required to achieve desired level of liberation, which is in tum controlled by the rod mill feed rate. This created a unique opportunity for modeling the effect of mineralogy on separation equipment and measuring reliability of the simulator in predicting perfonnance of non-concentration equipment, such as hydrocyclones and fine screens, under different operating and feed conditions. While performance of concentration devices including magnetic separator, hydroseparator and flotation banks was expected to show dependence on variation in mineralogy, particularly on liberation size, performance of classification and screening devices would be largely independent of the liberation characteristics. Therefore, the models were expected to reasonably simulate the performance of these devices for a given blend when plant data from the other blend was available. On the other hand, performance of grinding mills is mostly governed by the grindability characteristics of a given ore type. Differences in mineralogy may or may not have significant effect on their performance, depending on whether or not change in mineralogy create significant variations in grindability. If such variation occurs, then the question is: how can it be simulated? This study could also provide a guideline for refining grinding models to account for such variations.
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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.
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    Weakending of Taconite in Small Scale Explosive Tests
    (University of Minnesota Duluth, 2000-11-01) Niles, Harlan B; Bacca, D. A
    The primary objectives in blasting taconite are to produce broken rock that permits optimum digging and shovel loading rates with minimum secondary breakage and eliminates primary crusher delays. Since at least 1990, much of the blasting research by explosives companies, academics, and mining companies has been directed toward determining the downstream benefits of increased blast energy, particularly on crushing and coarse grinding. Several papers have been published that attempt to quantify the cost benefits. However, so many variables are involved that most benefits are only indicated or estimated. A report entitled "Effects of Blasting on Milling," by C. M. Lownds and D. A. Bocca of Viking Explosives & Supply, Inc., and K. Nielsen, Professor, Department of Geology and Mineral Resources Engineering, Norwegian University of Science and Technology, was presented at the 1997 Duluth, Minnesota, SME Annual Meeting. It describes a rather simple method of explosively loading taconite samples and of evaluating the explosive effects on grindability.1 " The small-scale explosive tests were conducted on taconite rock pieces collected from the back of a muckpile instead of on diamond drill core or sawed and drilled cubes, as described in previous work.2 · 3 The testwork described in the following report was proposed as a continuation of the tests on rock fragments to examine more extensively the effects of small-scale explosive tests on rock weakening.