Arsenic is a metalloid with atomic number 33. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal.
The main use of metallic arsenic is for strengthening alloys of copper and especially lead.
Arsenic is a common n-type dopant in semiconductor electronic devices, and gallium arsenide is the most common semiconductor in use after doped silicon.
Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, and insecticides. These applications are declining, however.
Arsenic is considered as highly toxic in both As III and As V forms. Elemental arsenic and arsenic compounds are classified as "toxic" and "dangerous for the environment" in the European Union under directive 67/548/EEC. The International Agency for Research on Cancer (IARC) recognizes arsenic and arsenic compounds as group 1 carcinogens, and the EU lists arsenic trioxide, arsenic pentoxide and arsenate salts as category 1 carcinogens
The two processes use iron as sacrificial metal.
In the selective cementation process, high yield of copper recovery is achieved (>90%) with a As final content <800ppm.
In the cementation process with As containing solutions, final concentrations, after treatment <1mg/l are achieved
Recovery of copper from As polluted solutions in the Molybdenum extraction industries.