The invention relates to a method for testing the content of free
mica in
machine-made sandstone
powder, which comprises the following steps: pre-treating
machine-made sand, and plating a
carbon layer on the surface of a pre-treated sample; performing
grating type point-by-point scanning on the surface of the prepared sample to generate and obtain a high-resolution back scattering image; calculating the area of stone
powder particles according to the back scattering image, and calculating the area of a
mica particle region to obtain the content of free
mica in the stone
powder; performing EDS scanning on the range of the free mica particles to obtain an X-
ray spectrum, and analyzing the X-
ray spectrum through
software to generate a multicolor layered element diagram; and combining the element diagrams to generate a multicolor layered
energy dispersion spectrum element diagram, calculating the area of a corresponding region according to the monochromatic
energy dispersion spectrum diagram of the
potassium element, calculating the area of a corresponding region according to the monochromatic
energy dispersion spectrum diagram of the
magnesium element, and further calculating the content of free
muscovite and the content of other free mica.