This paper describes a catalyst/wax separation technique based on dense-gas and/or liquid extraction of the soluble hydrocarbon components from the insoluble inorganic catalyst particles. The separation by extraction can also be performed in conjunction with magnetic separation of iron catalyst particles. Extractions of 4.91 wt % catalyst in wax were performed with n-butane, n-pentane, and n-hexane. Up to 91 wt % of the catalyst/wax feed mixture to the extractor could be recovered as a catalyst-free wax (combined yield of the second- and third-stage separators). High-temperature gel permeation chromatography was used to measure the average molecular weight of the extraction fractions. The extraction process separates the wax according to molecular weight. The lower molecular weight wax components are extracted from the catalyst/wax mixture and accumulate in the second-stage separator, while the higher molecular weight wax components remain in the first-stage separator. The low molecular weight wax fraction can be remixed with the catalyst and pumped back into the slurry reactor, reducing the average molecular weight, reducing the viscosity, and improving the transport properties of the reaction media while minimizing the chances of reactor gelation due to buildup of high molecular weight waxes.