[en] The neutron reflection method was applied to determine the moisture content in lateritic minerals. A moisture content higher than 3 wt% can be determined in 10 min of measuring time. This level of accuracy satisfies the requirements of industry. (author). 6 refs, 3 figs, 1 tab

[en] A review of the attempts to design, construct and evaluate borehole sondes for possible in situ analysis of mineral deposits is given. The design is based on the neutron capture gamma technique and the use of isotopic neutron sources. Various facilities have been developed in order to achieve this goal. Experiments in simulated boreholes have been carried out to evaluate the performance of these facilities. (author). 9 refs, 5 figs

[en] The paper reviews nuclear analytical techniques for control in uranium mining industries in China. On-line nuclear gauges give information on the process variables in uranium hydrometallurgical processing operations. These include systems for continuous monitoring of the uranium concentration in the process stream by gamma ray spectrometry, X ray absorptiometry and energy dispersive X ray fluorescence spectrometry; and on-stream continuous determination of the liquid-solid ratio of pulp in thickener using a radioisotope density gauge. (author). 13 refs, 5 figs

[en] A borehole laboratory model based on prompt gamma neutron activation analysis (PGNAA) using a 30 μg ²⁵²Cf neutron source has been designed and tested. This facility has been used to study salt-sand mixtures, as well as salt solutions. Some of the experimental data are compared with Monte Carlo results from a previous work. Measurement of the photopeak response of chlorine as a function of its energy and concentration, as well as the background moisture content, at a fixed absorbed density has been carried out. This facility is useful for the calibration of borehole experiments employing PGNAA techniques for bulk analysis of various media. (author). 6 refs, 7 figs

[en] Since basic data are required to determine the concentrations of elements in mineralogical analyses using nuclear techniques, the present status of nuclear models and codes for the evaluation of discrete gamma ray production cross-sections for prompt gamma ray spectroscopy is discussed. Particular attention is devoted to cross-section calculations of interfering reactions, in addition to dominant neutron inelastic scattering reactions for medium and heavy mass nuclei. These processes are relevant to specific photon production rates through different reaction channels. An application to ⁵⁶Fe is discussed with regard to the large discrepancies that exist between different sets of experimental data. (author). 25 refs, 3 figs, 4 tabs

[en] Technical developments over the last 20 years have resulted in the use of a number of on-stream analyser techniques, concepts and designs in the mineral industry. The technology accumulated has now made it possible to initiate system definition for the information needs of the user. Only after such an evaluation can an analyser system be developed that fulfils these needs by providing the desired analysis outputs. In most cases, this means combining different analyser techniques and designs at a mineral processing plant. Recent developments in on-stream X ray fluorescence (XRF), X ray diffraction (XRD) and conveyor belt analysers are reviewed. The major development in the field is the on-stream XRD analyser, which offers completely new possibilities of use in the mineral industry. The implications of these advances and of future developments in the area of on-line analysers are discussed from the point of view of the analyser industry itself and its customers in the mineral industry. (author). 5 refs, 12 figs

[en] Soil samples taken from the slopes of a mountain suspected of containing gold have been analysed at the Ghana Atomic Energy Commission using an americium-beryllium source of thermal neutrons, with a flux of 1.7x10⁵ neutrons·s^-1·cm^-2, using the neutron activation analysis technique. The average result of 8.4x10^-3g of gold, which corresponds to an average percentage of 4.2x10^-2%, is quite encouraging and shows that deep within the mountain there may be solid gold deposits. This is only the beginning of the project and future analysis will be directed at five other locations. (author). 2 refs, 1 tab

[en] Instrumental neutron activation analysis has been used in the determination of the presence of actinides (Th and U) in a number of 'raw' and 'washed' kaolins and in different size fractions separated from some of them. The results of analyses obtained are discussed and interpreted. Diadochic substitutions of actinides in the structures of some accessory (zircon) and secondary (crandallite) minerals were found to be important mechanisms for their concentration. (author). 9 refs, 4 figs, 3 tabs

[en] The instrumental activation method, together with the reconstructed 500 kW Da Lat nuclear research reactor, has since 1985 been used for the analysis of geological and environmental samples. Characterized by a high level of sensitivity, an acceptable degree of precision and high productivity, this method meets the requirements for geological surveys carried out in Viet Nam. The main results obtained using instrumental neutron activation analysis for uranium and thorium content determination in geochemical research in Viet Nam are summarized in the paper. (author). 8 refs, 1 fig., 8 tabs

[en] The feasibility of in-line uranium determination using energy dispersive X ray fluorescence is demonstrated. The development and subsequent construction of a circulation tank are described. The uranium detection limit in a flux obtained using this technique is 0.5 mg/L. (author). 6 figs, 4 tabs