In-Situ Leaching Of Crownpoint, New Mexico, Uranium Ore. III. Laboratory Study Of Strong Leaching Systems: Sodium Hypochlorite

1985 ◽  
Vol 25 (06) ◽  
pp. 875-880
Author(s):  
T.C. Vogt ◽  
E.T. Strom ◽  
W.F. Johnson ◽  
P.B. Venuto
Keyword(s):  
Sodium Hypochlorite ◽  
Laboratory Tests ◽  
Field Research ◽  
Carbonaceous Matter ◽  
Uranium Mineral ◽  
Oxidative Breakdown ◽  
Chloride Leaching ◽  
Bicarbonate Solutions ◽  
High Chloride

Mobil Research and Development Corporation Field Research Laboratory Dallas, Texas Abstract The organic carbonaceous matter found intimately associated with the uranium mineral in some Crownpoint ore trends appears to shield some of the uranium from contact by a chemically-mild leaching system. Sodium hypochlorite (NaOCl) is an oxidant strong enough to attack this carbonaceous matter and contact the trapped uranium mineral. Batch and pack laboratory tests showed that alkaline bicarbonate solutions containing 0.1–5.0 wt-% NaOCl were effective for rapid recovery of uranium from Crownpoint refractory ore. Recoveries of 90% and greater were obtained In the laboratory tests. However, NaOCl is such a strong oxidant that it reacts extensively with gangue minerals also present in the ore as well as with uranium. Since oxidation with NaOCl generates sodium chloride, high chloride levels would tend to build up in the leaching circuit. Electron mlcroprobe studies of ore samples after leaching with NaOCl showed the presence of holes and cracks in the residual carbonaceous matrix as well as the presence of chloride. Leaching with NaOCl is also associated with high levels of dissolved organic carbon. These observations suggest some degree of oxidative breakdown of the encapsulating organic matter by NaOCl, thereby facilitating oxidant attack on the uranium mineral.

scholarly journals In Situ Performance Assessment and Evaluation of Hydrophobic and Ultraviolet Protective Treatments for Historic Log Structures

2015 ◽  
Vol 38 ◽  
pp. 100-111
Author(s):  
Courtney Magill ◽  
Frank Matero
Keyword(s):  
Field Research ◽  
Accelerated Weathering ◽  
Assessment And Evaluation ◽  
Appropriate Treatment ◽  
Wood Coatings ◽  
Subsequent Phase ◽  
Initial Results ◽  
Ongoing Project

Beginning in the summer of 2015, research was conducted on protective wood coatings and accelerated weathering testing methods for architectural log and timber. A rack for supplementary natural weathering testing of hydrophobic and ultraviolet protective surface treatments for logs was also erected as a subsequent phase at Grand Teton National Park. This laboratory and field research is part of an ongoing project to develop an appropriate treatment for historic log structures in the region that will preserve their original fabric while maintaining the intended historic appearance of the buildings, i.e., unpainted. The weathering rack will be in place for upwards of five years to verify the lab-based results from Phase I and to determine the long-term durability of the chosen treatments on already aged materials in situ. This report addresses the methods and materials for preparation of the weathering rack and samples as well as the methods being used to monitor their progress and initial results. Readings will be taken yearly to monitor the effects of weathering on each treatment.

scholarly journals Using CPTs to derive thermal properties of soil

2020 ◽  
Vol 205 ◽  
pp. 04005
Author(s):  
Philip J. Vardon ◽  
Joek Peuchen
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Laboratory Tests ◽  
Field Investigation ◽  
Volumetric Heat Capacity ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
Penetration Tests ◽  
Properties Of Soil

A method of utilizing cone penetration tests (CPTs) is presented which gives continuous profiles of both the in situ thermal conductivity and volumetric heat capacity, along with the in situ temperature, for the upper tens of meters of the ground. Correlations from standard CPT results (cone resistance, sleeve friction and pore pressure) are utilized for both thermal conductivity and volumetric heat capacity for saturated soil. These, in conjunction with point-wise thermal conductivity and in situ temperature results using a Thermal CPT (T-CPT), allow accurate continuous profiles to be derived. The CPT-based method is shown via a field investigation supported by laboratory tests to give accurate and robust results.

scholarly journals Drenagem e acumulação de ar frio em noites de arrefecimento radiativo. Um exemplo no vale de Barcarena (Oeiras)

Finisterra ◽  
2012 ◽  
Vol 30 (59/60) ◽  
Author(s):  
António Lopes
Keyword(s):  
Drainage System ◽  
Field Research ◽  
Intermittent Flow ◽  
Cold Air ◽  
Climatological Field ◽  
Irradiation Process

THE COLD AIR DRAINAGE DURING CALM CLEAR NIGHTS: AN EXAMPLE IN HE BARCARENA VALLEY (OEIRAS, PORTUGAL) - The cold air drainage system is a recent climatological field research in Portugal. In the valley of Barcarena, a few kilometres westward from Lisbon, it was possible to detect the intermittent flow of the cold air drainage during two calm clear nights. We came to the conclusion that the cold air lakes are formed in situ by the irradiation process and also by the accumulation of the cold air drained along the valley slopes. The rugosity of the surface and the slow down of the cold air along the slope could be responsible for the oscillations of the cold air lakes thickness

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