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By R. L. Miller

Two samples of iron enriched basalt (IEB) containing simulated nuclear fuel and having two distinct microstructures were prepared and tested for uranium recovery. The IEBs are refractory towards leaching by ground water. However, the uranium content (15.8%) is high enough that if aggressive leaching techniques are used for uranium recovery, these materials could be considered as man-made uranium ores. The IEBs discussed in this report were prepared to simulate Three Mile Island-2 core debris. The crushed IEBs were treated using three different methods simulating potential industrial scale processes. In one method the IEBs were fused with sodium hydroxide then the cooled mass leached first with water then with dilute sulfuric acid; about 52% of the uranium was recovered in this case. In the second method the IEBs were treated with a sulfuric acid/hydrogen peroxide lixiviant and about 13% of the uranium was recovered. In the third technique the IEBs were leached with a sodium carbonate/sodium bicarbonate/hydrogen peroxide solution. Only about 0.1% of the uranium was recovered. The results of these screening tests suggest that the IEBs can be successfully treated for recovery of the contained uranium. Other studies would be required to determine if other values, such as zirconium or silver, could be recovered from the IEBs.

Jan 1, 1984

By Deon van Tonder, Bert Van Hege

Comparison of various technologies for uranium recovery from sulphuric acid leach solutions shows that Resin-in-Pulp (RIP) and/or Solvent extraction (SX) based processing routes are usually cost effective (11). A combined RIP-SX recovery-purification route and a CCD-SX recovery-purification route were investigated and optimised. The design basis used for the investigation was a production rate of 200 kg/h U3O8 over a solution concentration range of 40 to 1500 mg/L U3O8. The OPEX for the RIP-SX processing route was found to be sensitive to the variation in uranium concentration in the leach liquor. One of the main drivers for this trend is the leach acid concentration. Conversely, the CAPEX of the CCD-SX processing route was sensitive to the uranium concentration in the leach liquor. The leach acid concentration only affected the OPEX of the CCD-SX processing route modestly, as the bulk of the acid is recovered in a pre-leach circuit. Contrary to expectation, the effect of extractant loss assumptions on the overall processing route economics was found to be modest to insignificant. It should be noted that the CCD-SX processing route OPEX was more sensitive to extractant loss assumptions than the RIP-SX processing route OPEX. Economic optimum wash ratios were determined for the CCD-SX processing route and increased with leach concentration ? the increase in wash ratio was less than proportional. A 5-stage CCD configuration was found optimal over the concentration range investigated.

Jan 1, 2007

By William P. Lorenz

The paper describes a uranium by-product recovery plant operating within a copper leach, solvent extraction, and electrowinning circuit. The operation is unique because it is integrated into the main process stream of the copper circuit The plant processes 1408 m3/h of copper solutions containing about 10 mg/L of uranium. An Eluex type process was selected due to its compatibility with the copper leach plant. The paper includes an overview of the copper circuit

Jan 1, 1983

By William P. Lorenz

Overlying the sulfide mineralization at Anamax Mining Company's Twin Buttes Mine is an oxidized zone up to one hundred meters in thickness. The principal copper minerals in this zone are chryso-colla, tenorite, cuprite, native copper and copper-manganese-iron wad. This ox¬idized zone also contains minor amounts of uranium ranging in concentration from 0.002 to 0.010 percent. Since pit development through 1980, some 38 million tonnes of oxide ore with copper contents greater than 0.6 percent have been brought to the surface. Copper in the oxide ore is extracted at Twin Buttes in, an agitated sulfuric acid leach plant followed by solvent extraction and electrowinning producing 90 tonnes per day of copper cathode. During leaching of the oxide ores small amounts of uranium are solubilized along with the copper values. This is not limited to Twin Buttes as most acidic copper bearing leach solutions throughout the southwestern United States contain small amounts of uranium.1

Jan 1, 1982

By J Davidson

Ion exchange using strong base resins is a well established technology for the recovery and purification of uranium from sulfuric acid leach liquors. Production of uranium at the Beverley Mine in South Australia includes acidic in situ leaching, ion exchange and uranium precipitation. The salinity present in the groundwater results in a relatively high concentration of chloride in the leach liquor reporting to the ion exchange plant. The impact of chloride on the ion exchange process is discussed in this paper. The results presented show that an increased chloride concentration in the lixiviant solution feeding the ion exchange plant leads to increased uptake of chloride by the resin during the loading cycle. At the highest chloride concentration studied (7.5 g/L Cl) chloride took up to 60 per cent of the resin loading sites. The impact of the chloride can be summarised as follows: for a given uranium concentration in the lixiviant feed solution, the uranium loading decreased with increasing chloride concentration; a consequence of decreased uranium loading is an increase in the frequency of elution, with an associated increase in elution reagent costs; and for a given elution efficiency, the uranium concentration in the barrens is expected to increase with increasing chloride concentration.A few options were examined to counteract the impact of chloride: an increase in elution efficiency was targeted to reduce the amount of uranium returning to the loading circuit; increasing the pH improved uranium loading, but this was found to also increase iron extraction; and preliminary screening of alternative resins showed that the higher the theoretical ion exchange capacity of the strong base resin, the higher the uranium loading.Work is continuing on uranium recovery from saline leach liquors, specifically investigating the performance of alternative resins.

Jan 1, 2005

By K. M. Sarkar

"In many plant trial s(1,2) it has been proven that very small amounts (10 to 20 ppm) of uranium dissolved in mine water can be effectively recovered by the use of ion exchange resins and this uranium recovery has many advantages. In this paper an economic analysis at different levels of uranium contamination and at different market prices of uranium are described.For this study an operating mine-mill complex with a sulphuric acid leach circuit, followed by solvent extraction (SX) process, is considered, where contaminated mine water is available in excess of process requirements. lt is further assumed that the sulphuric acid eluant containing uranium would be mixed with the mill pregnant liquor stream that proceeds to the SX plant for final uranium recovery.Recovery by Ion ExchangeMine water, in this study, is defined as the water coming from the underground mine, or mine pits, and the run-off water from stockpiles, mine shops, crushing plant , washdown areas, etc.In nature, uranium mainly occurs in two stages; reduced (tetravalent) and oxidized (hexavalent) . The oxidation of sulphides present in the orebody often causes the presence of S04- and acidity in mine water, and this acidic water readily dissolves U+6 part of the depo sit. The react ion between hexavalent uranium, which is dissolved in water as U02+ 2 cation and S04 producing uranyl sulph ate as,"

Jan 1, 1984

By Wi11iam M. Leaders

Uranium Recovery Corporation was incorporated in the State of Florida in 1968 for the sole purpose of developing a method to economically recover uranium from Florida phosphoric acid. The preliminary laboratory work culminated in the demonstration of the process to United Nuclear Corporation in the spring of 1971. This was quickly followed by a pilot plant program to identify any unusual problems such as those arising from the day-to-day variation which occurs in a fertilizer phosphoric acid plant production system. After two years of pilot plant operation, United Nuclear Corporation purchased controlling interest in Uranium Recovery Corporation and committed several million dollars to the design and construction of the first commercial plant for this purpose in the State of Florida, or anywhere else in the United States, for that matter. After many start-up problems were resolved at the production plant located at the W. R. Grace fertilizer complex near Bartow, sustained production began March, 1971, and has continued to date. We still have some problems to solve but are currently producing sufficient uranium to make shipments to the UF6 converters for preparation of Florida uranium for use in nuclear power plant fuel materials.

Jan 1, 1978

By M. Fainerman-Melnikova

The use of strong base ion exchange resins for the extraction of uranium was pioneered in the 1950?s. Ion exchange technology is applicable to dilute leach solutions such as those obtained from in-situ, heap leaching or in-plant processing of low grade ores. A further advantage of ion exchange processes is that fluidised bed technology allows for treatment of solutions with a relatively high concentration of suspended solids and resin-in-pulp technology can treat leach slurries. However, the extraction of uranium with strong base resins is severely affected by the presence of chloride ions in solution. In areas where high quality water is not readily available, the use of saline water as process water would extend the potential application for ion exchange in uranium processing. Our research program has studied the effectiveness of a wide range of commercially available ion exchangers in uranium extraction from saline solutions. In the present work, we examine the impact of salinity (ranging from chloride concentrations found in groundwater to those present in sea water), on the uranium extraction with weak base anionic resins (WBA). The effect of pH and the presence of the competing impurities are also discussed.

Aug 1, 2010

By Catherine Cai

A granular sorbent, prepared by gel-coating polyethyleneimine (PEI) on high surface area silica followed by crosslinking with a low-molecular weight diepoxide, has significantly higher uranium capacity, greater salt tolerance, and faster kinetics than the commercial resin Dowex 21K. Though having lower U(VI)/Fe(III) selectivity than Dowex 21K, the gel-coated PEI affords much higher sorptions of both U(VI) and Fe(III) and also their separation by selective stripping with acid.

Jan 1, 1999

By A. Bhowmik

Uranium Refining is the process in which undesirable neutron absorbing elements such as Boron (B), Gadolinium (Gd), Cadmium (Cd), Europium (Eu), Samarium (Sm) and other heavy metals (Fe, Ni, Co, Ca, Mg etc.) are removed to make it nuclear pure. At present, Uranium refining is carried out by solvent extraction process by using organic based solvent e, g. TBP diluted with Kerosene. The above process generates lot of nitrate bearing liquid waste and degraded organic. In order to eliminate use of hazardous organic and ammonia for Uranium refining altogether, a new process has been developed. In the new process, Yellow Cake is dissolved in nitric acid and uranium peroxide hydrate is precipitated selectively from the solution leaving all the impurities in the solution by using commercial grade hydrogen peroxide at a pre-defined pH, U conc., temperature and stoichiometric quantity of hydrogen peroxide under mild agitation. The precipitate is filtered and washed with DM water to obtain nuclear pure product meeting purity standard as per ASTM C ? 753-99.The product is spray dried and calcined to obtain uranium oxide. The process eliminates use of organic, flammable, toxic chemicals, consumes less quantity of nitric acid and uses environfriendly chemical hydrogen peroxide. The process is simple and can be integrated in the mill. A patent application is entering national phase in several countries including CANADA and abstract/full paper is available in WIPO publication no: WO/2009/013759.

Aug 1, 2010

By N. C. J. Dempers, J. A. L. Parker, R. A. Wildenboer

More than half of global cobalt reserves are located in the Southern African Copperbelt, stretching over the northern tip of Zambia and southern area of the Democratic Republic of Congo. In these areas, cobalt is not typically produced as a primary product but as a byproduct of copper production. Ores from this region often contain uranium, which is readily leached under typical copper leach conditions and enters the process. Uranium does not pose a challenge to copper production, but it becomes a significant problem when it follows cobalt to the cobalt precipitation process and results in unacceptably high levels of U in the final Co product. This paper evaluates the existing process technologies that can be used to remove uranium from cobalt-bearing process streams, including phosphate precipitation and ion exchange. Advantages and disadvantages of the uranium removal processes are discussed, and important design considerations are highlighted.

Jan 1, 2023

By Jr. Koch

In the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) phase of its National Uranium Resource Evaluation (NURE) pro¬gram, the U.S. Department of Energy (DOE) samples about 1400 sites for stream sediments in each two-degree quadrangle of the National Topographic Nap Series (NTMS) and about 1200 sites for ground or stream water. Through a geological/statistical analysis, we find that NURE data are useful for assessing the uranium resources of the NTMS quadrangles. Our computer-implemented System for Uranium Resource Evaluation (SURE) calculates a score for each NTMS quadrangle based on the HSSR, geologic, and radiometric data; we score the four Colorado quadrangles--Pueblo, Montrose, Durango, and Trinidad--that comprise the study area. We interpret the scores in terms of geology and the known occurrences, which include the Hanson ore deposit with reserves of 30,000,000 lbs. U308 and the Pitch mine with reserves of 1,740,000 lbs. SURE depends in part on distinguishing mineralized or metalliferous granitoids from barren ones through "geochemical signatures."

Jan 1, 1980

By V. McLemore

New Mexico ranks 2nd in uranium reserves in the U. S., which amounts to 15 million tons ore at 0.277% U3O8 (84 million lbs U3O8) at $30/lb (EIA, 2006). The most important deposit in the state is sandstone within the Morrison Formation (Jurassic) in the Grants district. More than 340 million pounds of U3O8 have been produced from these deposits from 1948-2002, accounting for 97% of the total production in New Mexico and more than 30% of the total production in the United States. Sandstone uranium deposits are defined as epigenetic concentrations of uranium in fluvial, lacustrine, and deltaic sandstones. Three types of sandstone uranium deposits are recognized: tabular (primary, trend, blanket, black-band), roll-front (redistributed, post-fault, secondary), and fault-related (redistributed, stack, post-fault). Several companies are planning to mine these deposits by in-situ leaching.

Jan 1, 2007

By Robert Ditchburn

Within New Zealand?s extended EEZ there exists a vast submarine hydrothermal mineral resource associated with the Kermadec intra-oceanic arc. Along this arc more than thirty submarine volcanoes have been explored by GNS-lead researchers and, of these, c. 60% are known to be hydrothermally active and a site of active seafloor mineralisation. Assessment of whether this mineralisation is economically viable in terms of grade and tonnage is now underway. A key aspect of these investigations is determining the age of the mineralization which will have a direct bearing on its mode of formation, the time elapsed to amass an economic deposit and, ultimately, its capacity for sustainable extraction. Intact barite-rich ?black-smoker? chimneys similar to that depicted here (86 cm long) have been recovered from Brothers volcano in the southern part of the arc. These and other hydrothermal deposits provide evidence of active volcanic massive sulphide (VMS) mineralisation along the arc, the age of which can be determined from the disequilibrium between isotopes within the thorium or uranium decay chains. A chimney from Mariana arc has also been dated using these radiometric methods. The principle dating technique for chimneys up to 15,000 years old uses the decrease in 226Ra/Ba due to radioactive decay after the VMS was deposited. An initial ratio is obtained from chimneys that are proven to be less than 100 years old and this involves dating with 210Pb, 228Ra and 228Th that have short half-lives compared with 226Ra.

Jan 1, 2005

By Lynn C. Jacobsen

Among the unforeseen consequences of the 1973 Arab oil embargo has been a considerable array of new or increased taxes on the so-called energy minerals. These taxes will be the subject of this report. Both Federal and State taxes have been enacted, but I will be concerned mostly with state severance taxes and particularly those on uranium. Severance taxes are considered to include all taxes having the distinctive feature of being applied on a natural resource at the stage of extraction. The tax may be based on units of production or on value, and if on values it may be on gross value or on gross value less either arbitrary or cost-related deductions. The tax has a number of aliases - resource excise tax, conservation tax, privilege tax, mining excise tax, ad valorem production tax, and more - and this makes comparison of tax burdens among states difficult. The windfall profit tax on oil is an example of a severance tax at the Federal level. Severance taxes are an established feature of state tax systems, but they continue to be a controversial issue, and proposals to raise or modify existing severance taxes are regularly submitted to the legislatures of the Western energy producing states. No concensus exists as to what is a reason- able and proper level of severance taxation or to the form it should take. The taxes which have been adopted by the various states reflect the interaction of a variety of interests and the specific circum- stances in each state. What follows is a summary of theoretical, practical, and emotional viewpoints and arguments that surface in any statehouse in which a severance tax bill has been introduced. The New Mexico experience will be heavily relied upon. THE ECONOMISTS Marginal effects. A severance tax which is based on a gross percentage of revenue or on units of production is a constant addition to variable costs, and to the mine operator has the same effect as any other increase in operating costs. The direction of these effects is straightforward: the tax will cause the property to have a lowered present value, to be mined at a lower rate than without the tax, raise the minimum grade that will be mined, lead to lower total recovery, make marginal properties sub-marginal and discriminate in favor of richer, more profitable operations (Lockner, 1965; Steele, 1967). In the short run, production facilities are fixed and imposition of a severance tax will have little effect on production levels. In the longer term, capital is mobile and investment and exploration expenditures will shift from minerals and jurisdictions with high taxes to those with low taxes. Over a considerable range of taxation the effect will be to change the relative position of the taxing state, but an overly optimistic evaluation of the capacity of mineral producers to absorb a tax can bring an industry to a halt. It is generally acknowledged that imposition of high severance taxes on taconite in Minnesota stopped development completely, and that only the adoption of a constitutional amendment limiting the amount of taxes that could be imposed in the future brought the firms back and encouraged them to make the huge investments required (Weaton, 1969). A tax which is a percentage of the net operating income (gross revenue less cash operating costs) does not influence the cut-off grade for recovery nor change the time preference for extraction, and hence, is free of the negative features of the tax applied to gross revenues or units of production. In theory it is a more efficient tax but relative administrative complexity and inherent difficulty in predicting revenue have discouraged its use. The Wyoming severance tax on uranium, which uses grade of ore as well as price in establishing taxable value, is the most cost related, and hence, the most neutral and efficient of the various state severance taxes on uranium. Economic rent. Despite the discrimination and the anti-conservation aspect inherent in most severance taxes, economists generally endorse their use because they are seen as a vehicle to appropriate rents - that is, returns greater than the long-run competitive supply price. Conspicuous examples of supposed economic rents are the returns to oil producers because of the OPEC cartel, the returns of the uranium producers under AEC buying contracts in the 19501s, and the high prices obtained by the uranium producers for contracts entered into in the 1976-1979 period. Mining of coal in the Western states is believed by some to generate huge economic rents because of the OPEC caused increase in price of a competitive fuel (McLure, 1978, p. 261), and possibly because of clean air regulations favoring the burning of low-sulfur coal. In theory, such surplus returns could be taxed completely away without affecting supply. In practice, the situation is more complex (Steele, 1967, pp. 234-236); economic rent of mineral production is an elusive quantity involving as it does replacement costs, and technical and market risk, and it, like beauty or pornography, probably exists mostly in the eye of the beholder. Rent may also be perceived to be present in the upper portion of a cyclic market which also has a downside. Where rent exists, it is almost certain to be short-lived - cartels self- destruct, government subsidies end, competitive adjustments occur - but the taxes imposed to capture it tend to be immortal. There is little doubt that the perception of un- usual and undeserved (obscene) profits in the mid- and late 1970's was a major factor in the adoption of energy mineral taxes strikingly higher than had been previously considered. At the New Mexico legislature of 1977 supporters of a moderate tax were repeatedly confronted with some variant of the statement, "You can't expect me to believe that a

Jan 1, 1982

By G. Kordosky, A. Feather, M. Virnig, P. Crane

Introduction The post World War II nuclear arms race and interest in nuclear power generation resulted in a significant demand for uranium in the 1950’s. This led to the development of uranium solvent extraction technology and uranium became the first metal to be recovered on a large scale by solvent extraction (SX) (1), interestingly more than 100 years after the extraction of uranium from an acid nitrate solution using diethyl ether was first reported by Peligot.(2) For a variety of reasons discussed elsewhere (3,4) there have been upheavals in the supply demand picture and price for uranium since the 1960’s. (Figure 1) The low price of uranium from the mid 1980’s until 2004 resulted in a depression of new resource exploration and mine development along with uranium mine / mill closures and decommissioning. People with skills in uranium processing could not find suitable employment and many experienced engineers and metallurgists took jobs elsewhere or retired. This resulted in a significant brain drain with respect to uranium processing technology.

Jan 1, 2007

By Michael Davis

In the fairly recent past, with a history of cheap and abundant energy, it has been possible to predict with reasonable confidence that world energy demand would continue to double about every 15 years. Those who attempted to forecast the role of nuclear energy in future electricity generation could also start with the fairly safe assumption that electricity demand would increase even faster : with a doubling in demand about every 10 years. To estimate the likely future world demand for uranium it was then necessary to introduce a number of other assumptions including the rate of penetration of nuclear energy, the timing and the specific fuel requirements. This series of assumptions naturally compounded the uncertainty, but, remarkably, usually led to future uranium demands being overestimated. Such a bias which has almost always been observed in predictions made over the past 20 years has increasingly made uranium producers sceptical when expected to match the forecast demand with increased production capacity and supporting reserves. This scepticism has, of course, been reinforced by the persistence so far of a buyers' market in uranium throughout the entire period of emergence of commercial nuclear electricity generation.

Jan 1, 1974

By Grazyna Zakrzewska-Trznadel

The paper outlines the main objectives of the project that concern the evaluation of the possibility of uranium production from indigenous resources since Poland enters the nuclear program. The best available technologies are considered for uranium extraction and obtaining the yellow cake - U3O8. Liquid-liquid extraction with novel extracting agents, as well as membrane processes for separation of by-products will be tested in course of the project. The technological part will be completed with techno-economical analysis. Acknowledgement The studies were supported by the POIG project, No 01.01.02-14-094-09-00 ?Analysis of the possibility of uranium supply from domestic resources?.

Aug 1, 2010

By Edward S. Bell, Frank Angebrandt

"Nuclear reactors must have very large heat outputs to compete with conventional sources and the only feasible applications are in the production of electric power or large quantities of process steam. This paper considers alternative fuels for electric power generation in Canada. In a publicly owned utility, nuclear stations are economic for base-load generation for unit sizes of 500 mega• watts or larger where competitive fossil fuel costs are higher than about 30 cents per million Btu. In British Columbia, Alberta and Saskatchewan, fossil fuels will continue to be in adequate supply at costs lower than 30 cents per million Btu and thus, except for the special case of Vancouver Island, power generation in Western Canada will continue to be the hydraulic and conventional thermal type. In Eastern Canada, fossil fuel prices are likely to be higher than 30 cents per million Btu and most utilities will be able to install units of 500 mw or larger, so that nuclear power plants will provide much of the base-load generation required. Base-load generation comprises about two-thirds of the energy generated by power utilities. By 1990, the total annual electrical energy load will be over 600 billion kwh, with two-thirds of this load in Eastern Canada. Allowing for additional hydraulic resources which may be developed in Quebec, British Columbia and Manitoba, hydraulic generation is forecast to provide a little more than a third of this electrical energy, nuclear generation a third and fossil-fuelled generation about a quarter."

Jan 1, 1969

By John H. Puffer, Andreas H. Vassiliou

The Bemco mine area is within the Precambrian igneous and metamorphic rock terrain of the New Jersey Highlands province. Rocks In the area include a pyroxene granite, a hornblende granite, a quartz-oligoclase gneiss and a pegmatite and its host rock, a lens of amphibolite which becomes a sulfide-rich pyroxenite near the ore zone. The ore-bearing zone occurs along the hanging wall and foot-wall contact of the pegmatite which was emplaced discordantly into the amphibolite-pyroxenite.

Jan 1, 1985