The Albion process is an atmospheric leaching process for processing

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

concentrate A concentrate is a form of Chemical substance, substance that has had the majority of its base component (in the case of a liquid: the solvent) removed. Typically, this will be the removal of water from a Solution (chemistry), solution or suspens ...

refractory In materials science, a refractory material or refractory is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. Refractories are polycrystalline, polyphase, ...

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

and refractory

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...

. The process is important because it is the most cost-effective method currently in use for extracting both the zinc and

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

from concentrates that contain high lead levels (7% or greater). Zinc and lead often occur together and large remaining zinc deposits contain levels of lead that exceed what can be economically extracted through other techniques. The Albion process is not sensitive to the concentration grade and gives favorable recovery with both low grade and dirty concentrates.

Environmental A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

impact is also claimed to be mitigated using this technology because in contrast to other methods,

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activ ...

is not emitted and less energy is consumed over all.

History

Development of the Albion process started during the early nineties led by

Mount Isa Mines Mount Isa Mines Limited ("MIM") operates the Mount Isa copper, lead, zinc and silver mines near Mount Isa, Queensland, Australia as part of the Glencore group of companies. For a brief period in 1980, MIM was Australia's largest company. It has ...

. It was first patented in 1993. Several pilot plant projects were conducted in 1994 and 1995 which tested the feasibility of using the technology to process high arsenic gold and copper ore. The Albion Process has been successfully installed in seven projects globally: * GPM Gold Project (Gold, Armenia) * Las Lagunas Tailings (Gold, Dominican Republic) * Sable Copper Project (Copper, Chalcopyrite, Zambia) * Asturiana de Zinc (Zinc, Spain) * Nordenham Zinc Refinery (Zinc, Germany) * McArthur River (Zinc, Australia)

Process

The ore concentrate is first introduced into an IsaMill. This

comminution Comminution is the reduction of solid materials from one average particle size to a smaller average particle size, by crushing, grinding, cutting, vibrating, or other processes. In geology, it occurs naturally during faulting in the upper part of ...

step places a high degree of strain on the mineral

lattice Lattice may refer to: Arts and design * Latticework, an ornamental criss-crossed framework, an arrangement of crossing laths or other thin strips of material * Lattice (music), an organized grid model of pitch ratios * Lattice (pastry), an orna ...

and causes an increase in the number of

grain A grain is a small, hard, dry fruit (caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legum ...

boundary fractures and

lattice defects Lattice may refer to: Arts and design * Latticework, an ornamental criss-crossed framework, an arrangement of crossing laths or other thin strips of material * Lattice (music), an organized grid model of pitch ratios * Lattice (pastry), an orn ...

of several orders of magnitude. The increase in the number of defects within the mineral lattice "activates" the mineral, facilitating leaching. The rate of leaching is also enhanced, due to the increase in the mineral surface area. The oxidative leaching stage is carried out in agitated tanks operating at atmospheric pressure. Oxygen is introduced to the leach slurry to assist the oxidation. Leaching is autothermal, not requiring any external heat. Temperature is controlled by the rate of addition of oxygen, and by the leach slurry density.

Chemistry

The general reaction for the leaching process is:

MS_2 + \frac O_2 + H_2SO_4 \rightarrow MSO_4 + S^0 + H_2O

References

{{DEFAULTSORT:Albion Process Metallurgical processes