Experimental test of the sample reduction random error formula

Abstract

Introduction. An immediate estimate of the accidental error of sample reduction can only be made if the measurement method of execution is zero. This can be achieved by imitating the grains of a useful component with markers fully extracted from the reduced sample. The markers can be larger than 44 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 4. 2021 ISSN 0536-1028 the maximum size of the sample material and are extracted from the sample using screens. Markers whose granulometric composition matches the sample composition should be extracted completely from the reduced sample using a hand magnet in the case. Methodology. A small number of markers of the correct shape imitates forgeable gold grains or d99 platinum. A much larger number of free-form markers simulate the granulometric composition of a sample in the –1+0.5 mm class. It is necessary to find a form factor linking the particles real volume with the cube volume. For magnetite markers, the form factor is 0.4. Results and analysis. The samples have been reduced with regular shaped and free-form markers, which makes it possible to experimentally determine the error of reduction. Theoretical formulas found errors for the conditions of experiments. For experiments with the regular shaped markers, a 54.77– 58.43% relative reduction error has been obtained according to 480 parallel measurements. Theoretically determined 57.64% relative error falls into this range. Similar relative reduction errors with free-form markers are 8.82–10.00% and 9.15%. Conclusion. The fairness of the reduction error analytical formula has been directly evaluated for the first time. The reduction error analytical formula can be applied when analyzing the schemes of sample preparation.