Rice hulls, a by‐product of rice refining, naturally contain both silica and carbon compounds. The metallic impurity content of these hulls can be greatly decreased by appropriate leaching techniques, making the purified material suitable as a source of upgraded metallurgical silicon. The impurity level in the hulls after leaching, and after appropriate coking, is described, as well as techniques for adjusting the carbon to silica ratio in the coked materials.