Sodium metasilicate was investigated as a possible depressant in the separation of rutile from almandine. The study determined the floatability of the depressant through micro flotation tests of single and artificially mixed minerals. The adsorption behavior of sodium met silicate on the rutile and almandine surfaces was determined by the zeta potential measurement and X-ray Photoelectron Spectroscopy (XPS). The flotation tests for both single and artificially mixed minerals demonstrated that Sodium metasilicate could be an efficient depressant in the separation of rutile from almandine. Zeta potential measurements and XPS analysis depicted that more of Sodium metasilicate was adsorbed on almandine surface than that of rutile. Fe ions on the surface of almandine were the main active sites for collector attachment and adsorption. The element Si in sodium metasilicate was postulated to have contributed to depression of almandine too. The adsorption mechanism of sodium metasilicate on the surface of almandine was mainly attributed to the electrostatic interaction as well as chemical bonding.