scholarly journals Treatment of Molybdenite Ore Using a 2 kw Solar Furnace

1979 ◽  
Author(s):  
S. R. Skaggs ◽  
J. P. Coutures

Hydrometallurgical methods of extracting molybdenite (MoS2) from the raw ore consume 145 × 106 Btu ton of fossil fuel equivalent energy per ton of concentrate produced. Processing the ore using a solar heat source could save 56 percent of this energy. Thermodynamic considerations indicate that MoS2 is the easiest of the economically valuable ores to extract. If the technique can be developed with this ore, it may be possible to extend it to other ores. Oxidation of the sulfide to molybdic oxide (MoO3) is an exothermic process, and it should proceed autogenically if the concentration of MoS2 is high enough. Experiments to measure the specific heat of the raw ore were conducted to determine the crossover point for this autogenic reaction. Using a calorimeter, we found three distinct reaction temperature ranges corresponding to water and organic vapors, oxidation of pyrite (FeS2), and oxidation of molybdenite. The production rate of SO2 was measured for 0.5-g samples of three different concentrations of molybdenite: (a) 95 percent MoS2 concentrate, (b) 10 percent concentrate in the raw ore, and (c) the unadulterated raw ore. A crude mass balance was obtained between the reaction products and the unreacted ore in the hearth. The curves of reacted product wersus time look very similar to the curves of SO2 gas produced versus time. Both sets of curves show the reaction is more than 90 percent complete in one minute. This work is sponsored by the US Department of Energy and the French Center Nationale de Recherche Scientifique. It is a cooperative effort of the Los Alamos Scientific Laboratory in the US and the Laboratoire des Ultra-Refractaires and the Laboratoire d’Energetique Solaire in Odeillo, France.

Author(s):  
Mark A. Paisley ◽  
Donald Anson

The Biomass Power Program of the US Department of Energy (DOE) has as a major goal the development of cost-competitive technologies for the production of power from renewable biomass crops. The gasification of biomass provides the potential to meet his goal by efficiently and economically producing a renewable source of a clean gaseous fuel suitable for use in high efficiency gas turbines. This paper discusses the development and first commercial demonstration of the Battelle high-throughput gasification process for power generation systems. Projected process economics are presented along with a description of current experimental operations coupling a gas turbine power generation system to the research scale gasifier and the process scaleup activities in Burlington, Vermont.


2011 ◽  
Vol 1 (1) ◽  
pp. 269-276
Author(s):  
P. Thakur ◽  
J. Monk ◽  
J. L. Conca

Abstract The Waste Isolation Pilot Plant (WIPP), a US Department of Energy (DOE) facility, is a deep geologic transuranic waste disposal site designed for the safe disposal of transuranic (TRU) wastes generated from the US defense program. Monitoring is a key component of the development and operation of any nuclear repository and is important to the WIPP performance assessment. Initial concerns over the release of radioactive and chemical contaminants from the WIPP led to various monitoring programs, including the independent, academic-based WIPP environmental monitoring (WIPP-EM) program conducted by the New Mexico State University (NMSU) Carlsbad Environmental Monitoring and Research Center (CEMRC) located in Carlsbad, NM. The mission of CEMRC is to develop and implement an independent health and environmental monitoring program in the vicinity of WIPP and make the results easily accessible to the public and all interested parties. Under the WIPP-EM program constituents monitored include: (1) selected radionuclides, elements, and ions of interest in air, soil, vegetation, drinking water, surface water and sediment from within a 100-mile radius of WIPP as well as in the air exiting the WIPP exhaust shaft, and (2) internally deposited radionuclides in the citizenry living within a 100-mile radius of WIPP. This article presents an evaluation of more than tens years of environmental monitoring data that informed the public that there is no evidence of increases in radiological contaminants in the region that could be attributed to releases from the WIPP. Such an extensive monitoring program and constant public engagement is an ideal model for all nuclear waste repositories anywhere in the world.


2014 ◽  
Vol 21 ◽  
pp. 78
Author(s):  
Samuel S. Webster

This paper analyzes the impact of the federal Production Tax Credit on the development of wind energy in the US. Following an analysis of the incentives these policies produce for wind energy generation and integration, this paper finds that, although the Production Tax Credit has proven effective at promoting some level of wind power development, the effectiveness of the Production Tax Credit varies by region and by itself is unlikely to achieve the deep levels of wind power penetration desired by some policymakers and the U.S. Department of Energy.


2019 ◽  
Vol 16 (1) ◽  
pp. 299-325
Author(s):  
Atef Elmahdy ◽  
Hayam Taha ◽  
Mohamed Kamel ◽  
Menna Tarek

The influence of mechanical bending to tuning the hydrogen storage of Ni-functionalized of zigzag type of boron nitride nanotubes (BNNTs) has been investigated using density functional theory (DFT) with reference to the ultimate targets of the US Department of Energy (DOE). Single Ni atoms prefer to bind strongly at the axial bridge site of BN nanotube, and each Ni atom bound on BNNT may adsorb up to five, H2 molecules, with average adsorption energies per hydrogen molecule of )-1.622,-0.527 eV( for the undeformed B40N40-? = 0 , ) -1.62 , 0-0.308 eV( for the deformed B40N40-? = 15, ) -1.589,  -0.310 eV( for the deformed B40N40-? = 30, and ) -1.368-  -0.323 eV( for the deformed B40N40-? = 45 nanotubes respectively. with the H-H bonds between H2 molecules significantly elongated. The curvature attributed to the bending angle has effect on average adsorption energies per H2 molecule. With no metal clustering, the system gravimetric capacities are expected to be as large as 5.691 wt % for 5H2 Ni B40N40-? = 0, 15, 30, 45. While the desorption activation barriers of the complexes nH2 + Ni B40N40-? = 0 (n = 1-4) are outside the (DOE) domain (-0.2 to -0.6 eV), the complexes nH2 + Ni- B40N40-? = 0 (n = 5) is inside this domain. For nH2 + Ni- B40N40-? = 15, 30, 45 with (n = 1-2) are outside the (DOE) domain, the complexes nH2 + Ni- B40N40-? = 15, 30, 45 with (n = 3-5) are inside this domain. The hydrogen storage of the irreversible 4H2+ Ni- B40N40-? = 0, 2H2+ Ni- B40N40-? = 15, 30, 45 and reversible 5H2+ Ni- B40N40-? = 0, 3H2+ Ni- B40N40-? = 15, 30, 45 interactions are characterized in terms of density of states, pairwise and non-pairwise additivity, infrared, Raman, electrophilicity and molecular electrostatic potentials. Our calculations expect that 5H2- Ni- B40N40-j = 0, 15, 30, 45 complexes are promising hydrogen storage candidates.


1990 ◽  
Vol 34 (1-4) ◽  
pp. 145-148 ◽  
Author(s):  
M. Moscovitch ◽  
K.J. Velbeck ◽  
G.M. Bencke

Abstract The method of response interpretation for determining dose equivalents of a new multi-element thermoluminescence dosemeter in mixed photon-beta and photon-neutron fields is described. The four TL chips are LiF:Mg,Ti, each covered by its own unique filter. Experiments to determine the response of the dosemeter and to test the dose calibration algorithm were performed according to the standard established by the US Department of Energy Laboratory Accreditation Program (DOELAP). It has been shown that the dosemeter response can be used to identify the mixture type. The accuracy of the system has been proven in blind testing to be well within DOELAP tolerance limits in all test categories.


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