Abstract: A method of bonding a first thin crystalline metal to a second thin metal ch as metallic glass is disclosed. Initially, the metallic glass is coated with a thin thermal barrier layer. Next, the first metal is heated to a temperature sufficient for diffusion bonding. Finally, the metallic glass is maintained at ambient temperature as the metallic glass is diffusion bonded to the crystalline metal. The thermal barrier layer prevents the metallic glass from reaching a phase transition temperature during the diffusion bonding. Consequently, a composite product having a base layer of crystalline metal and an outer layer of metallic glass is produced. Preferably, the diffusion bonding is produced by evacuated roll-bonding and the coating is attached to the metallic glass by electroplating. A plurality of metallic glass layers and crystalline metal layers can be bonded together to produce a sandwiched composite product.

Abstract: Arsenic is recovered from flue dusts by forming an aqueous slurry of the dust, treating the slurry with SO.sub.2 gas to solubilize arsenic, and precipitating the arsenic as As.sub.2 O.sub.3 by means of sulfuric acid.