The neutron capture gamma-ray spectroscopy facility assembled at the Institute of Radiochemistry, KfK (for analytical purposes) using a252Cf neutron source with a strength of 6·107 n/s, has been used to check its applicability and sensitivity for quantitative analyses of ores. The analysis of Sm, Cd and Mn in phosphate and monazite rock samples has been carried out. The results from this study show a variation of about 25% from the values determined by RNAA method. This discrepancy could be mainly due to the low signal-to-background ratio observed which is caused by (i) scattering of the source gammarays by the target, and (ii) interference from the 2223.1 keV neutron capture hydrogen gamma-rays produced by the moderated materials and from their compton scattering in the detector. To overcome these difficulties we suggest to introduce a 2.5 cm thick polyethylene sheet between the detector6Li-cap shielding and the target as well as to increase the detection solid angle. Also the strength of the252Cf neutron source should be increased by an order of magnitude and the neutron beam should be collimated to obtain the optimal thermal neutron flux with a low level of252Cf gamma-rays. This can be achieved by setting up between the neutron source and the target a conical polyethylene collimator with a thickness of 10 cm containing a 1 cm thick lead sheet.