[en] Radioisotope X-ray flourescence method of determination of grain size below 75μm in mineral slurries of copper ores has been woeked out. Two radioisotope sources of different energies of X-rays (²³⁸Pu and ²⁴¹Am) have been used for the excitation of copper in slurry. The influence of variable copper and solids contents of slurry and variation of parameters of grain size distribution on measurement results have been studied. The estimated accuracy (absolute 1 st.dev.) of determination of grain size below 75 μm amounts 4%. (author)

[en] A dynamic difference circuit for continuous substraction of number of counts proceeding from two separate radiometric channels is presented. Construction and operation of circuit separate blocks is described. An error analysis of counts difference measurement was performed. Results of theoretical calculations were found to be in good agreement with experimental data. (author)

[en] Radiometric method for determination of gold and indium in electroplating bath and washings in concentration range of 0.01 to 1.0% and 1 to 4 g/l for Au and In respectively, was developed. X-ray fluorescence of Au L series and In K series, excited using radioisotope sources was measured. The matrix effect was eliminated by additional measurement of back-scattered primary radiation. Ratio of Au L X-rays and backscattered radiation is a linear function of gold concentration. The estimated total error (1 s) for Au analysis is 0.002 to 0.01% Au depending on the Au concentration. For determination of indium the error amounts 0.040 gIn/l. (author)

[en] The possibility of using an EDXRF method for particle-size control of multimetallic ore slurry has been studied. Zinc-lead-iron ore slurry has been chosen as an example of multimetallic specimens. The influence of metals concentration, solids content and parameters of grain-size distribution on the accuracy of the method has been calculated. The proposed method was checked experimentally with the use of samples simulating Zn-Pb ore slurries. (author)

[en] Radiometric methods of determination of platinum and palladium (0.1 to 5% of Pt and 0.1 to 2% of Pd), gold and indium (0.01 to 1% of Au and 1 to 4 gIn/l) and of platinum and rhodium (0.1 to 9% of Pt and 0.05 to 1% of Rh) in aqueous solution have been worked out. A suitable measuring device has been designed and constructed. The methods are based on the measurement of characteristic radiation of the L line for gold and platinum and of the K-series for indium, palladium and rhodium, as well as on the measurement of scattered radiation from a ²³⁸Pu source. The r.m.s. error of the determination varies from 0.01 to 0.10% pf Pt, 0.002 to 0.01% of Au and 0.01 to 0.15% of Pd depending on the concentration. In the case of Rh and In the r.m.s. errors are 0.008% and 0.04 gIn/litr, respectively. (author)

[en] A Monte Carlo model was developed for simulation of x-ray fluorescence from cylindrical mineral grains in geological samples including primary and secondary fluorescence events. The inter-element and geometrical effects in XRF microanalysis of mineral grains were studied. Calculations were performed for grains of ZnS located in a CaCO₃ matrix. The results of calculation indicated that the intensities of excited characteristic x-rays depend strongly on the diameter and thickness of the irradiated grains. (author)

No abstract available

[en] A method of correction for particle-size effects in XRF analysis of ore slurry is proposed. The use of calculated heterogeneity factor for correcting the intensity of fluorescent X-rays of determined element was suggested. The possibility of using a value of weight fraction of particles smaller than 75 μm for determining the heterogeneity factors was studied. The method was tested experimentally with the use of samples simulating zinc-lead and copper ore slurries. (author)

[en] Published in summary form only

[en] The possibility of using an EDXRF method for particle-size control of multimetallic ore slurry has been studied. Zinc-lead-iron ore slurry has been chosen as an example of multimetallic specimens. The influence of metals concentration, solids content and parameters of grain-size distribution on the accuracy of the method has been calculated. The proposed method was checked experimentally with the use of samples simulating Zn-Pb ore slurries. (author)