Leaching of gold from flotation waste by thiourea

well-known precious metal in the world. It is synonymous with
wealth in the financial market and jewellery. However, its use has a
wide range of applicability in biomedicine, electronic engineering
and other industries. Primary gold resources are limited and have
been significantly depleted in recent decades. To cover the current
demand, it is necessary to process secondary sources containing gold
such as heaps, tailings, lean ores or electrical waste. New and
especially more efficient technological procedures are needed for the
processing of these secondary sources. From an environmental point
of view, a hydrometallurgical process is considered to be more
appropriate than a pyrometallurgical process, in which very toxic
fumes enter the air. This work investigates the leaching of gold from
flotation wastes using thiourea. It is flotation waste that is the target
group of materials that are a source of precious metals. An interesting
gold content is present in our waste sample (Hodruša Hámre tailings
pond), but its evaluation depends on the setting of suitable
technological conditions. In this work, thiourea is used as an
alternative leaching agent to toxic cyanide, which is banned in
Slovakia and many countries around the world due to its high
environmental risk. The results of the study are described with
respect to the gold recovery under optimized thiourea leaching
conditions