Systems and methods for metal recovery

A system comprising:

• an oxidizing roaster configured to receive oxygen gas and configured to heat a metal bearing material to temperatures of from about 200° C. to about 800° C.;
• a reducing roaster configured to receive at least one of carbon monoxide gas and hydrogen gas and configured to heat the metal bearing material to temperatures of from about 200° C. to about 800° C.;
• a basic leaching vessel configured to receive a roasted metal bearing material from the roaster;
• a crystallizer configured to crystallize the roasted metal bearing material to yield a preprocessed metal bearing material;
• and
• an acid leaching vessel configured to receive the preprocessed metal bearing material from the crystallizer.

A process comprising:

• oxidizing sulfides of copper by roasting under oxygen gas to produce an oxidized copper bearing material;
• reducing copper by roasting the oxidized copper bearing material under at least one of hydrogen and carbon monoxide to produce a roasted copper bearing material;
• leaching the roasted copper bearing material using ammonia to yield a pregnant leach solution;
• precipitating copper containing compounds from the pregnant leach solution;
• and
• leaching the copper containing compounds in acid medium.