A feasible, portable and convenient density measurement method for minerals via magnetic levitation

Abstract

This work proposes an improved magnetic levitation (IML) method for measuring the density of minerals in outdoor exploration by horizontally setting the magnetic levitation device. The measuring characteristic of the method is analyzed and verified by a series of beads with known densities. Combined with the usage of different paramagnetic media, the method obtained a measuring range from 1.094 g cm−3 to 9.949 g cm−3, which could cover all common minerals. The method was then applied for measuring different minerals with densities from 1.828 g cm−3 to 6.742 g cm−3. The densities of the minerals were also measured using the pycnometer method and the densitometer method for comparison. The results showed that the IML method is more applicable for measuring single mineral particle with high accuracy (with a maximum of 1.08% relative error), while the other two commonly used methods have a significantly larger mean square error (0.076 g cm−3–0.331 g cm−3, 3–10 times larger approximately) and required samples of a much larger volume to achieve the same accuracy. Compared with the two common methods, the IML method consumes the least time of 22 min for 3 trials, which may save at least 55.1% in terms of time consumed in the measuring process. To our best knowledge, this is the first time that magnetic levitation has been employed in the characterization of minerals in outdoor exploration. Compared with the common methods, the IML method was found to be portable, convenient, and low-cost for outdoor exploration.