Rigaku NEX CG EDXRF for Analysis of Limestone

Applied Rigaku Technologies, Inc. has announced a new empirical method for the elemental analysis of Mg, Al, Si, Ca and Fe in limestone.

Application Note #1108 demonstrates the effectiveness of the polarized excitation and Cartesian geometry design of the Rigaku NEX GC energy dispersive X-ray fluorescence (EDXRF)spectrometer to provide superior light element sensitivity.

Calcium-bearing minerals are widely used in agriculture, energy, and road construction.

Limestone has long been used as a key material in the construction of buildings and monuments, as well as the production of glass. It is used as a raw material in the production of quicklime, cement and mortar.

Limestone is also used as a scrubber stone in the desulfurization of flue gas and as a reagent in blast furnaces to extract iron from ore.

Purified, limestone has many uses as a calcium supplement in foods and animal feeds, and well as a whitener in cosmetics.

For this application, each sample is prepared by grinding to a fine, dry, homogeneous powder of <200 mesh (<75um particle size) using a ball mill.

For measurement, 5 g of sample was pressed using 20 tons pressure for 30 seconds to form a pellet.

The results shown indicate performance in a “real-world” situation where a short analysis time of 140 sec is required.

Two secondary targets were used, the HOPG polarizer for light elements (Na-Cl) at 100 seconds, and the Cu target for Fe at 40 seconds.