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Control of pyrite surface chemistry in physical coal cleaning (open access)

Control of pyrite surface chemistry in physical coal cleaning

The successful separation of pyrite from coal by flotation is dependent to a large extent upon the selectivity of the process, and the use of a pyrite depressant is one of the most important and cost-effective techniques for achieving this. This report evaluates the effects of three factors on the floatability of pyrite. These are (1) the superficial oxidation of pyrite, (2) the contamination of pyrite surfaces by carbonaceous matter, and (3) pulp redox potentials. XPS (x-ray photoelectron spectroscopy) and IR spectrometry have been used to identify surface reaction products. Microflotation, laboratory-scale conventional flotation and microbubble column flotation were used to quantify the effects of these factors. It was found that low (reducing) pulp potentials are effective depressants of pyrite (more so for fresh, unoxidized samples than for oxidized samples), whilst at the same time do not materially affect coal flotation.
Date: June 24, 1992
Creator: Luttrell, G. H.; Yoon, R. H. & Ou, Z. S.
Object Type: Report
System: The UNT Digital Library
Control of pyrite surface chemistry in physical coal cleaning (open access)

Control of pyrite surface chemistry in physical coal cleaning

To better understand the surface chemical properties of coal and mineral pyrite, studies on the effect of flotation surfactants (frother and kerosene) on the degree of hydrophobicity have been conducted. The presence of either frother or kerosene enhanced the flotability of coal and mineral pyrite with a corresponding decrease in induction time over the pH range examined. Scanning electron microscopy (SEM) results indicate a correlation exists between the sample surface morphology and crystal structure and the observed hydrophobicity. As a result of the data obtained from the surface characterization studies, controlled surface oxidation was investigated as a possible pyrite rejection scheme in microbubble column flotation.
Date: June 24, 1992
Creator: Luttrell, G. H.; Yoon, R. H.; Zachwieja, J. & Lagno, M.
Object Type: Report
System: The UNT Digital Library
Control of pyrite surface chemistry in physical coal cleaning (open access)

Control of pyrite surface chemistry in physical coal cleaning

One of the most difficult separations in minerals processing involves the differential flotation of pyrite and coal. Under practical flotation conditions, they are both hydrophobic and no cost-effective method has been developed to efficiently reject the pyrite. The problem arises from inherent floatability of coal and pyrite. Coal is naturally hydrophobic and remains so under practical flotation. Although pyrite is believed to be naturally hydrophilic under practical flotation conditions it undergoes a relatively rapid incipient oxidation reaction that causes self-induced'' flotation. The oxidation product responsible for self-induced'' flotation is believed to be a metal polysulfide, excess sulfur in the lattice, or in some cases elemental sulfur. It is believed that if incipient oxidation of pyrite could be prevented, good pyrite rejection could be obtained. In order to gain a better understanding of how pyrite oxidizes, a new method of preparing fresh, unoxidized pyrite surfaces and a new method of studying pyrite oxidation have been developed this reporting period.
Date: June 24, 1992
Creator: Yoon, R. H. & Richardson, P. R.
Object Type: Report
System: The UNT Digital Library

[Photograph 2012.201.B0352.0650]

Photograph used for a newspaper owned by the Oklahoma Publishing Company.
Date: June 24, 1992
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B0245.0618]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Kay Lindsey, Minna Hall, Jerry Love and Evie Wood, from left, look through Decorator's Show House scrapbooks at a recent appreciation luncheon for Show House chairmen."
Date: June 24, 1992
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B0257.0421]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Johnny Herrera (29) eases past Terry McCarl during Wednesday's World of Outlaws race at State Fair Speedway"
Date: June 24, 1992
Creator: Gooch, Steve
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B0306B.0193]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Capt. Russ dear of the Oklahoma County sheriff's office uses a mop handle Wednesday to help test the strength of an experimental security screen placed over the glass block windows in one cell of Oklahoma County's new 1,200-cell jail."
Date: June 24, 1992
Creator: Hoke, Doug
Object Type: Photograph
System: The Gateway to Oklahoma History

[Photograph 2012.201.B0410B.0082]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "The Graham-Carroll House Bed and Breakfast in this 1935 Victorian Gothic house."
Date: June 24, 1992
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History
Drop oscillation and mass transfer in alternating electric fields (open access)

Drop oscillation and mass transfer in alternating electric fields

In certain cases droplet direct contact heat transfer rates can be significantly enhanced by the application of an alternating electric field. This field can produce shape oscillations in a droplet which will enhance mixing. The theoretical evaluation of the effect of the interaction of the field with drop charge on the hydrodynamics has been completed for small amplitude oscillations. Previous work with a zero order perturbation method was followed up with a first order perturbation method to evaluate the effect of drop distortion on drop charge and field distribution. The first order perturbation results show secondary drop oscillations of four modes and two frequencies in each mode. The most significant secondary oscillation has the same mode and frequency as the second mode oscillation predicted from the first order perturbation work. The resonant frequency of all oscillations decrease with increasing electric field strength and drop charge. Work is currently underway to evaluate the heat transfer enhancement from an applied alternating electric field.
Date: June 24, 1992
Creator: Carleson, T.E.
Object Type: Report
System: The UNT Digital Library
Control of pyrite surface chemistry in physical coal cleaning. Seventh quarterly progress report, March 1, 1991--May 31, 1991 (open access)

Control of pyrite surface chemistry in physical coal cleaning. Seventh quarterly progress report, March 1, 1991--May 31, 1991

The removal of pyrite from coal by flotation or any other surface chemistry based separation process is often hampered by the apparent hydrophobicity of the mineral. Results obtained in this project suggest that corrosion processes are responsible for the apparent hydrophobicity of pyrite in aqueous environments. Characterization of the corrosion products of pyrite in acidic and alkaline solution has been performed using electrochemical (cyclic voltammetry and single-potential-step chronoamperometry) and spectroscopic techniques (X-ray photoelectron spectroscopy -- XPS). The nature of the surface products have been correlated with hydrophobicity determined from in-situ contact angle measurements. The results show that pyrite hydrophobicity is influenced by either the oxidation or reduction conditions of the system.
Date: June 24, 1992
Creator: Luttrell, G. H.; Yoon, R. H. & Zachwieja, J. B.
Object Type: Report
System: The UNT Digital Library
Control of pyrite surface chemistry in physical coal cleaning. Tenth quarterly progress report, December 1, 1991--February 29, 1992 (open access)

Control of pyrite surface chemistry in physical coal cleaning. Tenth quarterly progress report, December 1, 1991--February 29, 1992

One of the most difficult separations in minerals processing involves the differential flotation of pyrite and coal. Under practical flotation conditions, they are both hydrophobic and no cost-effective method has been developed to efficiently reject the pyrite. The problem arises from inherent floatability of coal and pyrite. Coal is naturally hydrophobic and remains so under practical flotation. Although pyrite is believed to be naturally hydrophilic under practical flotation conditions it undergoes a relatively rapid incipient oxidation reaction that causes ``self-induced`` flotation. The oxidation product responsible for ``self-induced`` flotation is believed to be a metal polysulfide, excess sulfur in the lattice, or in some cases elemental sulfur. It is believed that if incipient oxidation of pyrite could be prevented, good pyrite rejection could be obtained. In order to gain a better understanding of how pyrite oxidizes, a new method of preparing fresh, unoxidized pyrite surfaces and a new method of studying pyrite oxidation have been developed this reporting period.
Date: June 24, 1992
Creator: Yoon, R. H. & Richardson, P. R.
Object Type: Report
System: The UNT Digital Library
Control of pyrite surface chemistry in physical coal cleaning. Second quarterly progress report, December 1, 1989--February 28, 1990 (open access)

Control of pyrite surface chemistry in physical coal cleaning. Second quarterly progress report, December 1, 1989--February 28, 1990

To better understand the surface chemical properties of coal and mineral pyrite, studies on the effect of flotation surfactants (frother and kerosene) on the degree of hydrophobicity have been conducted. The presence of either frother or kerosene enhanced the flotability of coal and mineral pyrite with a corresponding decrease in induction time over the pH range examined. Scanning electron microscopy (SEM) results indicate a correlation exists between the sample surface morphology and crystal structure and the observed hydrophobicity. As a result of the data obtained from the surface characterization studies, controlled surface oxidation was investigated as a possible pyrite rejection scheme in microbubble column flotation.
Date: June 24, 1992
Creator: Luttrell, G. H.; Yoon, R. H.; Zachwieja, J. & Lagno, M.
Object Type: Report
System: The UNT Digital Library
Control of pyrite surface chemistry in physical coal cleaning. Fifth quarterly progress report, September 1, 1990--November 30, 1990 (open access)

Control of pyrite surface chemistry in physical coal cleaning. Fifth quarterly progress report, September 1, 1990--November 30, 1990

The successful separation of pyrite from coal by flotation is dependent to a large extent upon the selectivity of the process, and the use of a pyrite depressant is one of the most important and cost-effective techniques for achieving this. This report evaluates the effects of three factors on the floatability of pyrite. These are (1) the superficial oxidation of pyrite, (2) the contamination of pyrite surfaces by carbonaceous matter, and (3) pulp redox potentials. XPS (x-ray photoelectron spectroscopy) and IR spectrometry have been used to identify surface reaction products. Microflotation, laboratory-scale conventional flotation and microbubble column flotation were used to quantify the effects of these factors. It was found that low (reducing) pulp potentials are effective depressants of pyrite (more so for fresh, unoxidized samples than for oxidized samples), whilst at the same time do not materially affect coal flotation.
Date: June 24, 1992
Creator: Luttrell, G. H.; Yoon, R. H. & Ou, Z. S.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: LO92-001 (open access)

Texas Attorney General Opinion: LO92-001

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification;construction of the term "revocation" for the purposes of section 6.19,article 179e,V.T.C.S.,and related questions (RQ 188)
Date: June 24, 1992
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Actuator system history of safety rod lower latch problems review of latch inspection video tapes (open access)

Actuator system history of safety rod lower latch problems review of latch inspection video tapes

During pre-restart testing the safety rod at position X26-YlO bound after being driven approximately two (2) feet out of the reactor. Subsequently, the rod was manually returned to it`s seated position. Inspection of the lower latch showed that the latch locking plunger button (screwed on to the bottom of the plunger shaft and retained by a pin through a hole drilled through the button and the plunger shaft) was missing. The shaft failed through the hole drilled for the retaining pin. The button, with the retaining pin intact, was found lodged between the safety rod upper adapter collar and the top of the safety rod thimble top fitting. Analysis of the safety rod latch and accompanying forest guide tube design provided assurance that this type of failure would not cause binding during the ``scramming`` of the safety rods. Inspection of all of the ``K`` safety rod lower latches revealed six other latches with missing plunger buttons, and nine with other non-conformances which required latch replacement. A history search conducted by Reactor Engineering Design, Components Handling Group, is included in this report. The history search shows that latch design modifications, as a part of initial development of the latch system and …
Date: June 24, 1992
Creator: Banks, J. J.
Object Type: Report
System: The UNT Digital Library
Preliminary assessment of RTR and visual characterization for selected waste categories (open access)

Preliminary assessment of RTR and visual characterization for selected waste categories

The first transuranic (TRU) waste shipped to the Waste Isolation Pilot Plant (WIPP) will be for the WIPP Experimental Program. The purpose of the Experimental Program is to determine the gas generation rates and potential for gas generation by the waste after it has been permanently stored at the WIPP. The first phase of these tests will be performed at WIPP with test bins that have been filled and sealed in accordance with the test plan for bin scale tests. A second phase of the testing, the Alcove Test, will involve drummed waste placed in sealed rooms within WIPP. A preliminary test was conducted at the Rocky Flats Plant (RFP) to evaluate potential methods for use in the characterization of waste. The waste material types to be identified were as defined in the bin-scale test plan -- Cellulosics, Plastic, Rubber, Corroding Metal/Steel, Corroding Metal/Aluminum, Non-corroding Metal, Solid Inorganic, Inorganic Sludges, other organics and Cements. A total of 19 drums representing eleven different waste types (Rocky Flats Plant -- Identification Description Codes (IDC)) and seven different TRUCON Code materials were evaluated. They included Dry Combustibles, Wet Combustibles, Plastic, light Metal, Glass (Non-Raschig Ring). Raschig Rings, M{sub g}O crucibles, HEPA Filters, Insulation, …
Date: June 24, 1992
Creator: Ziegler, D. L.
Object Type: Report
System: The UNT Digital Library
Actuator system history of safety rod lower latch problems review of latch inspection video tapes (open access)

Actuator system history of safety rod lower latch problems review of latch inspection video tapes

During pre-restart testing the safety rod at position X26-YlO bound after being driven approximately two (2) feet out of the reactor. Subsequently, the rod was manually returned to it's seated position. Inspection of the lower latch showed that the latch locking plunger button (screwed on to the bottom of the plunger shaft and retained by a pin through a hole drilled through the button and the plunger shaft) was missing. The shaft failed through the hole drilled for the retaining pin. The button, with the retaining pin intact, was found lodged between the safety rod upper adapter collar and the top of the safety rod thimble top fitting. Analysis of the safety rod latch and accompanying forest guide tube design provided assurance that this type of failure would not cause binding during the scramming'' of the safety rods. Inspection of all of the K'' safety rod lower latches revealed six other latches with missing plunger buttons, and nine with other non-conformances which required latch replacement. A history search conducted by Reactor Engineering Design, Components Handling Group, is included in this report. The history search shows that latch design modifications, as a part of initial development of the latch system and …
Date: June 24, 1992
Creator: Banks, J. J.
Object Type: Report
System: The UNT Digital Library
Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. [801Methyl tert-butyl ether] (open access)

Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. [801Methyl tert-butyl ether]

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. (2) Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. (3) Addition of methanol to slurry phase FT synthesis making iso-olefins. During the sixth quarter we completed the construction of the slurry bubble column reactor (SBCR), conducted initial shake-down experiments in a cold-flow mode, and finalized the selection process of the acid catalysts for conversion of syngas-produced alcohols and isobutylene to MTBE (scheme 2). Tasks 3, 4, and 5 are awaiting complete implementation of the SBCR system.
Date: June 24, 1992
Creator: Marcelin, G.
Object Type: Report
System: The UNT Digital Library
Control of pyrite surface chemistry in physical coal cleaning. Third quarterly progress report, March 1, 1990--May 31, 1990 (open access)

Control of pyrite surface chemistry in physical coal cleaning. Third quarterly progress report, March 1, 1990--May 31, 1990

Correlation of the hydrophobicity measurements of coal and mineral pyrite with changes in the surface composition of the samples as determined by x-ray photoelectron spectroscopy (XPS) reveals that similar surface oxidation products are found on both mineral and coal pyrite samples. The surface oxidation layer of these samples is comprised of different amounts of hydrophilic species (iron hydroxy-oxides and/or iron oxides) and hydrophobic species (polysulfide or elemental sulfur). The resulting hydrophobicity of these samples may be attributed to the ratio of hydrophilic (surface oxides) to hydrophobic (sulfur-containing) species in the surface oxidation layer. Also, coal pyrite samples were found to exhibit a greater degree of superficial oxidation and a less hydrophobic character as compared to the mineral pyrite samples.
Date: June 24, 1992
Creator: Luttrell, G. H.; Yoon, R. H.; Zachwieja, J. B. & Lagno, M. L.
Object Type: Report
System: The UNT Digital Library
Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 6, January 1, 1992--March 31, 1992 (open access)

Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 6, January 1, 1992--March 31, 1992

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. (2) Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. (3) Addition of methanol to slurry phase FT synthesis making iso-olefins. During the sixth quarter we completed the construction of the slurry bubble column reactor (SBCR), conducted initial shake-down experiments in a cold-flow mode, and finalized the selection process of the acid catalysts for conversion of syngas-produced alcohols and isobutylene to MTBE (scheme 2). Tasks 3, 4, and 5 are awaiting complete implementation of the SBCR system.
Date: June 24, 1992
Creator: Marcelin, G.
Object Type: Report
System: The UNT Digital Library
The Paducah Post (Paducah, Tex.), Vol. 86, No. 19, Ed. 1 Wednesday, June 24, 1992 (open access)

The Paducah Post (Paducah, Tex.), Vol. 86, No. 19, Ed. 1 Wednesday, June 24, 1992

Weekly newspaper from Paducah, Texas that includes local, state, and national news along with advertising.
Date: June 24, 1992
Creator: Taylor, Jimmye C.
Object Type: Newspaper
System: The Portal to Texas History
The Clifton Record (Clifton, Tex.), Vol. 97, No. 26, Ed. 1 Wednesday, June 24, 1992 (open access)

The Clifton Record (Clifton, Tex.), Vol. 97, No. 26, Ed. 1 Wednesday, June 24, 1992

Weekly newspaper from Clifton, Texas that includes local, state, and national news along with advertising.
Date: June 24, 1992
Creator: Smith, W. Leon
Object Type: Newspaper
System: The Portal to Texas History
The Aransas Pass Progress (Aransas Pass, Tex.), Vol. 84, No. 18, Ed. 1 Wednesday, June 24, 1992 (open access)

The Aransas Pass Progress (Aransas Pass, Tex.), Vol. 84, No. 18, Ed. 1 Wednesday, June 24, 1992

Weekly newspaper from Aransas Pass, Texas that includes local, state, and national news along with advertising.
Date: June 24, 1992
Creator: Cole, Mary
Object Type: Newspaper
System: The Portal to Texas History

[Photograph 2012.201.B1430.0267]

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Computer entrepreneurs Gary W. Zimmerman, left, and John Musgrove discuss their new electronic filling software, their contribution to the paper-free office."
Date: June 24, 1992
Creator: Klock, Roger
Object Type: Photograph
System: The Gateway to Oklahoma History