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Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production.
Date:
January 1, 2004
Creator:
Walqui, H. J.; Eisele, T. C. & Kawatra, S. K.
Object Type:
Report
System:
The UNT Digital Library
NON-PRODUCTION FUELS REPROCESSING, CENTRIFUGATION STUDIES ON VARIOUS DISSOLVER EFFLUENT SOLUTIONS
>The proposed flowsheets for reprocessing of nonproduction fuels include centrifugal separation of particulate matter from various dissolver effluent solutions. The settling characteristics of process solids were determined in water and in cold process solutions. Uranium dioxide particles will be recovered from Zirflex and Sulfex cladding waste solutions, and core-dissolver solutions will be centrifuged for removal of ZrO/sub 2/, metallic slimes, siliceous matter, and uranium-bearing solids. (W.L.H.)
Date:
December 1, 1959
Creator:
Amos, L.C.
Object Type:
Report
System:
The UNT Digital Library
Progress Report on Carnotite Studies; Carbonate Processes: September 1949
This is a progress report on the carbonate process, compiled by the chemical development department of the Carbide and Carbon Chemicals Corporation's Y-12 plant, covering the month of September, 1949. In the previous month, the problem of immediate interest to the Monticello operation were listed. Projects that were left incomplete during that time were continued during this month, as well as a brief investigation of the process in which raw ore is leached with sodium carbonate, the sands and slime separated, the sands leached with acid, and the slimes roasted in a pellitized form.
Date:
October 6, 1949
Creator:
Brown, K. B. & Coleman, C. F.
Object Type:
Report
System:
The UNT Digital Library
Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This is being accomplished by mathematical modeling of the grinding circuits to determine how to correct this problem. The approaches taken included (1) Modeling of the circuit to determine process bottlenecks that restrict flowrates in one area while forcing other parts of the circuit to overgrind the material; (2) Modeling of hydrocyclones to determine the mechanisms responsible for retaining fine, high-density particles in the circuit until they are overground, and improving existing models to accurately account for this behavior; and (3) Evaluation of advanced technologies to improve comminution efficiency and produce sharper product size distributions with less overgrinding.
Date:
October 1, 2004
Creator:
Eisele, T. C.; Kawatra, S. K. & Walqui, H. J.
Object Type:
Report
System:
The UNT Digital Library
Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This is being accomplished by mathematical modeling of the grinding circuits to determine how to correct this problem. The approaches taken included (1) Modeling of the circuit to determine process bottlenecks that restrict flow rates in one area while forcing other parts of the circuit to overgrind the material; (2) Modeling of hydrocyclones to determine the mechanisms responsible for retaining fine, high-density particles in the circuit until they are overground, and improving existing models to accurately account for this behavior; and (3) Evaluation of advanced technologies to improve comminution efficiency and produce sharper product size distributions with less overgrinding.
Date:
March 31, 2005
Creator:
Kawatra, S. K.; Eisele, T. C.; Weldum, T.; Larsen, D.; Mariani, R. & Pletka, J.
Object Type:
Report
System:
The UNT Digital Library
Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This is being accomplished by mathematical modeling of the grinding circuits to determine how to correct this problem. It has been determined that, for mixtures of approximately equal quantities of high-density minerals (such as iron oxides) and low-density minerals (such as quartz), existing hydrocyclone models fail to accurately predict the hydrocyclone behavior. Since the hydrocyclone is the key unit controlling the particle size, an accurate model of these units is required and is being fully developed. Experimental work has demonstrated that the previous models are inaccurate due to incorrect assumptions concerning the change in hydrocyclone cut size as a function of changing particle density.
Date:
July 1, 2004
Creator:
Walqui, H. J.; Eisele, T. C. & Kawatra, S. K.
Object Type:
Report
System:
The UNT Digital Library
OPTIMIZATION OF COMMINUTION CIRCUIT THROUGHPUT AND PRODUCT SIZE DISTRIBUTION BY SIMULATION AND CONTROL
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This is being accomplished by mathematical modeling of the grinding circuits to determine how to correct this problem. The approaches taken included (1) Modeling of the circuit to determine process bottlenecks that restrict flowrates in one area while forcing other parts of the circuit to overgrind the material; (2) Modeling of hydrocyclones to determine the mechanisms responsible for retaining fine, high-density particles in the circuit until they are overground, and improving existing models to accurately account for this behavior; and (3) Evaluation of advanced technologies to improve comminution efficiency and produce sharper product size distributions with less overgrinding.
Date:
January 1, 2005
Creator:
Kawatra, S. K.; Eisele, T. C.; Weldum, T.; Larsen, D.; Mariani, R. & Pletka, J.
Object Type:
Report
System:
The UNT Digital Library
Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project is to improve the energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. This will save energy by reducing the amount of material that is ground to below the target size, and will also reduce the quantity of material wasted as slimes that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production. In the first quarter of this project, work was completed on a basic comminution model that will be used to carry out the subsequent project tasks. This phase of the work was supported by the Electric Power Research Institute, as their cost-share contribution to the project. The model has been implemented as an Excel spreadsheet, which has the advantage of being a very portable format that can be made widely available to the industry once the project …
Date:
December 1, 2001
Creator:
Kawatra, S. K.; Eisele, T. C. & Walqui, H. J.
Object Type:
Report
System:
The UNT Digital Library
Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing he product size distribution, so that the amount of excessively fine material produced can be minimized. This will save energy by reducing the amount of material that is ground below the target size, and will also reduce the quantity of materials wasted as ''slimes'' that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production. In the seventh quarter of this project, analysis of the plant operation identified sources of overgrinding in the circuit. Overgrinding was primarily caused by two effects: (1) The hydrocyclones used to close the circuit and remove fully-ground particles from the circuit were preferentially returning high-density ore particles to the secondary mills for regrinding even after they were already ground to pass the desired product size, and (2) The primary grinding mills were operating at less than full capacity, suggesting …
Date:
October 1, 2002
Creator:
Kawatra, S. K.; Eisele, T. C. & Walqui, H. J.
Object Type:
Report
System:
The UNT Digital Library
OPTIMIZATION OF COMMINUTION CIRCUIT THROUGHPUT AND PRODUCT SIZE DISTRIBUTION BY SIMULATION AND CONTROL
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing he product size distribution, so that the amount of excessively fine material produced can be minimized. This will save energy by reducing the amount of material that is ground below the target size, and will also reduce the quantity of materials wasted as ''slimes'' that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production. In previous quarters, it was determined that the primary grinding mills were operating at less than full capacity, suggesting that a shift of grinding load to the primary mills could liberate more material before it reached the secondary mills, allowing more complete liberation with a coarser grind. In the eighth quarter, further analysis was carried out to determine the full extent of the benefit that could be obtained by this shift in grinding load. A key part of this …
Date:
January 1, 2003
Creator:
Kawatra, S.K. & T.C. Eisele, H.J. Walqui
Object Type:
Report
System:
The UNT Digital Library
Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. This will save energy by reducing the amount of material that is ground below the target size, and will also reduce the quantity of materials wasted as slimes that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production. In the sixth quarter of this project, work was centered on analyzing the considerable plant data gathered during the first year of the project. Modeling is being carried out of the hydrocyclone portion of the grinding circuit, since this has been identified as the primary source of overgrinding and inefficiency.
Date:
July 1, 2002
Creator:
Kawatra, S. K.; Eisele, T. C. & Walqui, H. J.
Object Type:
Report
System:
The UNT Digital Library
Radiological survey of the inactive uranium-mill tailings at Green River, Utah
The uranium-mill tailings at Green River, Utah, are relatively low in /sup 226/Ra content and concentration (20 Ci and 140 pCi/g, respectively) because the mill was used to upgrade the uranium ore by separating the sand and slime fractions; most of the radium was transported along with the slimes to another mill site. Spread of tailings was observed in all directions, but near-background gamma exposure rates were reached at distances of 40 to 90 m from the edge of the pile. Water erosion of the tailings is evident and, since a significant fraction of the tailings pile lies in Brown's Wash, the potential exists for repetition of the loss of a large quantity of tailings such as occurred during a flood in 1959. In general, the level of surface contamination was low at this site, but some areas in the mill site, which were being used for nonuranium work, have gamma-ray exposure rates up to 143 ..mu..R/hr.
Date:
March 1, 1980
Creator:
Haywood, F. F.; Christian, D. J.; Ellis, B. S.; Hubbard Jr., H. M.; Lorenzo, D. & Shinpaugh, W. H.
Object Type:
Report
System:
The UNT Digital Library
Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project was to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process were used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced could be minimized. The goal was to save energy by reducing the amount of material that was ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that were too fine to be useful. Extensive plant sampling and mathematical modeling of the grinding circuits was carried out to determine how to correct this problem. The approaches taken included (1) Modeling of the circuit to determine process bottlenecks that restrict flowrates in one area while forcing other parts of the circuit to overgrind the material; (2) Modeling of hydrocyclones to determine the mechanisms responsible for retaining fine, high-density particles in the circuit until they are overground, and improving existing models to accurately account for this behavior; and (3) Evaluation of the potential of advanced technologies to improve comminution efficiency and produce sharper product size distributions with less overgrinding. The mathematical models were used to simulate novel circuits for minimizing overgrinding and increasing throughput, …
Date:
July 1, 2005
Creator:
Kawatra, S. K.; Eisele, T. C.; Weldum, T.; Larsen, D.; Mariani, R. & Pletka, J.
Object Type:
Report
System:
The UNT Digital Library
Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control
The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production. During this quarter, work was focused on three areas: (1) The mathematical relationship developed for predicting plant throughput was improved, based on ore work index and equipment parameters measured in the plant over an extended period. It was determined that the model would need to fit two distinct regimes of grinding circuit operation, depending on the work index of the feed ore. (2) Plans for a proposed change in the circuit configuration at an iron ore plant are …
Date:
April 1, 2003
Creator:
Walqui, H. J.; Eisele, T. C. & Kawatra, S. K.
Object Type:
Report
System:
The UNT Digital Library
Radium-226 in vegetation and substrates at inactive uranium mill sites
Results of a study of the content of radium-226 in plants growing on inactive uranium mill tailings sites in the Four Corners Region of the southwestern United States and in plants grown under greenhouse conditions with minimal surficial contamination are reported. Field plant samples and associated substrates were analyzed from two carbonate tailings sites in the Grants Mineral Belt of New Mexico. Radium activities in air-cleaned samples ranged from 5 to 368 pCi/g (dry weight) depending on species and location: activities in plants growing on local soils averaged 1.0 pCi/g. The talings and local soils contain 140 to 1400 pCi/g and 2.1 pCi/g, respectively. An evaluation of cleaning methods on selected samples showed that from 17 to 79% of the radium activity measured in air-cleaned samples was due to surficial contamination, which varied with species and location. A survey of 18 inactive uranium mill sites in the Four Corners Region was performed. Radium activity in plant tissues from nine species ranged from 2 to 210 pCi/g on bare tailings and from 0.3 to 30 pCi/g on covered tailings The radium content in most of the soil overburdens on the covered tailings piles was 10 to 17 pCi/g. An experiment was …
Date:
January 1, 1980
Creator:
Marple, M.L.
Object Type:
Report
System:
The UNT Digital Library
Concentration Experiments with the Siliceous Red Hematite of the Birmingham District, Alabama
From Introduction: "The results of concentration experiments with these ores made a more thorough and systematic investigation desirable. In consequence, the author subsequently collected samples in the district, and these became the basis of the experimental work described in this report. The results are published by the Bureau of Mines as a part of its efforts to increase efficiency in the utilization of mineral resources."
Date:
1917
Creator:
Singewald, Joseph T., Jr.
Object Type:
Report
System:
The UNT Digital Library
Jigging, Classification, Tabling, and Flotation Tests of Coals Presenting Difficult Washing Problems, with Particular Reference to Coals from Pierce County, Washington
From Content and Arrangement of Report: "For the convenience of the reader the bulletin has been divided into two parts. Part I describes the investigation and summarizes the most important results. Part II gives the detailed data of the best of the washing tests by each process."
Date:
1931
Creator:
Bird, B. M. & Marshall, S. M.
Object Type:
Report
System:
The UNT Digital Library
Physical Stability of Asphalt Emulsion Admix Seal Radon Barrier for Uranium Mill Tailings
Pacific Northwest Laboratory, is investigating the use of an asphalt emulsion admix seal to reduce the release of radon from uranium mill tailings. A key requirement of any cover system is its long-term stability; the cover must withstand failure over very long periods of time. An important determinant of overall cover system stability is the integrity of the 6.35-cm (2.5-in.) thick asphalt admix seal. Therefore, the physical stability of this seal was examined. The investigation considered the mechanical interaction between the tailings pile and cover. The potential effect of differential settlement of the tailings pile on the integrity of the seal system was also examined. Results indicate that the minimum span length the seal could withstand without failing is 0.34 m (1.1 ft). This assumes a differential settlement of 4.92 cm (1.94 in.) at the center resulting from the application of a 0.76-m (2.5-ft) cover. At spans greater than 0.60 m (1.97 ft), no tensile strain would develop.
Date:
September 1, 1983
Creator:
Gates, T.E.
Object Type:
Report
System:
The UNT Digital Library
The War Whoop (Abilene, Tex.), Vol. 34, No. 6, Ed. 1, Friday, October 19, 1956
Weekly student newspaper from McMurry College in Abilene, Texas that includes local, state and campus news along with advertising.
Date:
October 19, 1956
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Gross alpha activity as an estimator of radium-226 activity in soils and tailings at an inactive uranium mill tailings site
Gross alpha activity in surface tailings and surface soils from one inactive uranium mill site has been shown to be an accurate estimator of /sup 226/Ra activity. An exponential regression, /sup 226/Ra = 387(e/sup 0.00166..cap alpha../ - 1), where /sup 226/Ra activity is in picoCuries per gram and gross alpha activity is in counts per minute per sample, gave a good fit for samples ranging in gross alpha activity from 3 to 1082 cpm/sample. A linear regression, /sup 226/Ra = 1.05 ..cap alpha.. + 1.78, has been calculated, which shows gross alpha activity to be an excellent estimator of /sup 226/Ra activity in soils contaminated with tailings. The percentage of gross alpha activity attributable to /sup 226/Ra activity has been calculated to be 7.2, 17.6, 18.3, and 17.0 for uncontaminated soils, contaminated soils, tailings, and the total set of samples, respectively.
Date:
October 1, 1978
Creator:
Dreesen, D.R. & Wienke, C.L.
Object Type:
Report
System:
The UNT Digital Library
URANIUM RECOVERY RESEARCH SPONSORED BY THE NUCLEAR REGULATORY COMMISSION AT PACIFIC NORTHWEST LABORATORY QUARTERLY PROGRESS REPORT OCTOBER TO DECEMBER 1983
None
Date:
February 1, 1984
Creator:
Foley, M. G.; Deutsch, W. J.; Gee, G. W.; Hartley, J. N.; Kalkwarf, D. R.; Mayer, D. W. et al.
Object Type:
Report
System:
The UNT Digital Library
The Thresher (Houston, Tex.), Vol. 8, No. 12, Ed. 1 Thursday, November 30, 1922
A weekly student newspaper from the Rice Institute in Houston, Texas that includes campus news and commentaries along with advertising.
Date:
November 30, 1922
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
The Rice Thresher (Houston, Tex.), Vol. 44, No. 2, Ed. 1 Friday, September 21, 1956
A weekly student newspaper from the Rice Institute in Houston, Texas that includes campus news and commentaries along with advertising.
Date:
September 21, 1956
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
The Thresher (Houston, Tex.), Vol. 20, No. 1, Ed. 1 Thursday, September 13, 1934
A weekly student newspaper from the Rice Institute in Houston, Texas that includes campus news and commentaries along with advertising.
Date:
September 13, 1934
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History