Development of Bi-2223 magnetic separation system

A prototype of a cryocooler cooled Bi-2223 magnet system for magnetic separation was constructed. The magnet system has 200 mm room temperature bore and generates fields higher than 1T in 11-liter room temperature space. The magnet was tested at various temperatures and excitation speeds. The magnet was cyclically excited up to 1.7 T at the speed of 1.7 T/min with various periodic times. The temperature gradually increased with the number of excitations, however, the temperature saturated at 28-38 K for the periodic times longer than 9 min, and stable operation of the magnet was obtained. A demonstration of magnetic separation of aquatic slurry containing fine /spl alpha/-hematite paramagnetic particle was performed by using ferromagnetic stainless steel fibers as a magnetic filter. Almost 100% of hematite particles were successfully separated from the slurry.