[en] Considered are the methods of mineral enrichment based on the use of the radioation of various types. The physical essence of enrichment processes is presented, their classification is given. Described are the ore properties influencing the efficiency of radiometric enrichment, methods of the properties study and estimation of ore enrichment. New possibilities opened by radiometric enrichment in the technology of primary processing of mineral raw materials are elucidated. A considerable attention is paid to the main and auxiliary equipment for radiometric enrichment. The foundations of the safety engineering are presented in a brief form. Presented are also results of investigations and practical works in the field of enrichment of ores of non-ferrous, ferrous and non-metallic minerals with the help of radiometric methods

[en] Process for treating alkaline leaching liquors of uranium ores, the characteristics of which include: - an operation to neutralize at least a fraction of these liquors by an acid in conditions leading to the decarbonation of the said fraction, - where required, joining the neutralized and non neutralized fractions, - adding lime to the mixture of the two fractions in an amount and under conditions giving rise to the precipitation of virtually all the uranium in solution, - separating the precipitate formed constituting a calcic pre-concentrate of the surface floating solution

No abstract available

[en] Rio Algom Mines Ltd. owns eight U mines and mills in the Elliot Lake district of Ontario, seven of which were producing before 1960. At present only one mine is operating and meeting current contract requirements. Under present economic conditions, it is not feasible to mine ore of less than 2.0 lb/ton U₃O₈, although there are very large reserves below this grade. Rio Algom is interested in preconcentration for three possible applications: to extend ore reserves by permitting use of lower grade ore, to reduce costs on processing of present grade ore, and to reduce capital investment in expanding production to meet future production goals. Rio Algom has been investigating various applicable preconcentration processes since the early 1950s to date on laboratory and pilot-plant scale. Methods investigated include gravity concentration by sink-float, high-intensity wet magnetic separation, flotation of U, flotation of acid consumers, and a number of electronic sorting methods including radiometric, photometric, and conductimetric. No method tested has yet been satisfactory under Rio Algom's criteria of U recovery and cost, principally because U loss has been too high for a useful weight rejection. Metallurgical results of the preconcentration test work and the economic assessment therefrom are reviewed. (U.S.)

[en] The Bundelkhand massif comprising a variety of Archean-Paleoproterozoic granitoids along with low grade and high-grade metamorphites and located in the centre of the Indian Plate, underwent extension during Paleoproterozoic period, resulting in the formation of homotaxial intracratonic Bijawar and Sonrai basins in the south and Gwalior basin in the northern margin. The Bijawar and Sonrai basins are typified by their characteristic sediments and basic volcanic rocks. A feature common to both the basins, is the overwhelming occurrence of phosphatic rocks across stratigraphy and lithotype in the Bijawar basin and its confinement to the basal part of the sedimentary column in Sonrai basin. Most of these rocks are primarily of marine origin, and later subjected to periods of repeated phosphatic redistribution. Multiple episodes of such phosphatisation culminates in the proliferation and enrichment of phosphate in the upper Bijawar rocks of Bijawar basin (phosphatic breccia of Hirapur-Mardeora) and lower Bijawar rocks of Sonrai basin (phosphatic breccia of Lalitpur). Apart from these established phosphatic rocks in both the basins, quartz reefs occurring in the basement as well as the lower Bijawar Malhera Chert Breccia Formation in Bijawar basin at places are endowed with anomalously high phosphate content. The phosphatic component in all the lithotypes is in the form of apatite varying in form from microcrystalline to well formed coarser crystal aggregate comprising cement, veins and botroidal encrustations. Irrespective of its spatial, temporal and paragenetic position, it invariably registers weak to moderate radioactivity, due to the presence of uranium within it, as is evident from microprobe data. Although intra-grain and inter-grain distribution of uranium is found to be random and erratic, in general, it is observed that uranium tends to be enriched in the later generation phosphates, due to secondary process of dissolution and reprecipitation. The present paper, with fresh inputs from petrological, geochemical, minerochemical and isotope data pertaining to apatite from all these diverse units, not only explores the already established association of uranium and phosphate in these basins but also provides new insight to the phosphatic quartz reef within the basement and the phosphatised arenaceous sediments of the lower Bijawar Formation (author)

[en] At IPEN-CNEN/SP, fractionation of rare earths aiming to obtain high purity lanthanides is carried out. The initial raw material is a rare earth concentrate in the form of chloride mixture, obtained from industrialization of monazites or from some fractions previously enriched in determined lanthanides provided by Nuclemon - S.P. The previous enrichment by conventional methods, such as oxidative separation of cerium and fractionation of some groups by basicity difference using alkaline agents as sodium and ammonium hydroxides, as well as the technique of homogeneous precipitation with urea and, also the initial fractionation by solvent extraction, is done. Obtained the first concentrate fractions in some rare earths, the technique of ion exchange with strong cation resin for obtaining high purity lanthanides, is applied. The analytical processes using several techniques are established. (M.C.K.)

[en] The results of the X-ray fluorescence separation method for tungsten-bearing ores of different types of deposits are considered. Feasibilities of the method and instruments at excitation of characteristic radiation of the tungsten K-series are estimated. Prospects for application of the X-ray fluorescence separation method for complex tungsten-bearing ores in mineral composition, high selectivity of separation at excitation of the tungsten K-series and the possibility of improving the raw material quality due to considerable separation of final tailings are shown

[en] An ore sample of about 0.2 percent uranium from Quirke Mine was subjected to radiometric sorting by Ore Sorters Limited. Approximately 60 percent of the sample weight fell within the sortable size range: -150 + 25 mm. Rejects of low uranium content (< 0.01 percent) representing less than 1 percent U loss were removed at a cut-off 0.3 counts/cm² (2 counts/in²) but only 7.6 percent of the ore, by weight, was discarded. At 0.8-0.9 counts/cm² (5-6 counts/in²) a significant amount of rejects was removed (> 25 percent) but the uranium loss was unacceptably high (7.7 percent). Continuation of the testwork to improve the results is proposed by trying to extend the sortable size range and to reduce the amount of fines during crushing

[en] For enrichment of granular ores one must know conditions of stable operation of a radiometer. For this purpose it is necessary to allow for the contribution of the scattered and weakened flow of gamma-quanta and the integral flow of radiation which is registered by the detector. This allows selection of parameters for the exit circuit of the measuring block of the radiometer for two radiometric enrichment of ores, gamma-absorption and gamma-gamma methods

[en] This article is an overview of the spot market prices and trading volume in U3O8 and Separative Work Units. The time frame covered is March/April 1994, and during this period, 7.1M pounds of U3O8 equivalent were traded in the spot concentrate sector, approximately 10M pounds of long-term contracts were signed, conversion services for approximately 5M kilograms of Uranium were dealt, and enrichment services for approximately 2M SWU were agreed upon