u2022 The following are the types of the materials that we can purchase. u00a7 Copper Residue/ sludge/ ash/dross/slag u00a7 Nickel Residue/ sludge/ ash/dross/slag u00a7 Cobalt Residue/ sludge/ ash/dross/catalyst u00a7 Tin Residue/ sludge/ ash/dross/slag u00a7 Zinc Residue/ sludge/dross/slag u00a7 Molybdenum Residue /Catalyst u00a7 Precious Metal Residue/Concentrate/sludge( Silver, Indium, Gold, Platinum, ) u00a7 Brass residue u00a7 Lead residue Show More