SMART DOG MINING^TM
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Solar cells/panels rely heavily on mining.

While much of the recent wave of interest has been on storage systems, particularly batteries, the development of solar or photovoltaic cells should also be of interest to the mining industry.  A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect.

Solar cells can be classified into first, second and third generation cells. The first generation cells—also called conventional, traditional or wafer-based cells—are made of crystalline silicon, the commercially predominant PV technology.  Second generation cells are thin film solar cells, that include amorphous silicon,  Cadmium telluride (CdTe) and  Copper indium gallium selenide (CIGS) cells and are commercially significant in utility-scale photovoltaic power stations, building integrated photovoltaics or in small stand-alone power system.  The third generation of solar cells includes a number of thin-film technologies often described as emerging photovoltaics—most of them have not yet been commercially applied and are still in the research or development phase.

The major material for first generation cells is silicon. Silicon of 96–99% purity is made by reducing quartzite or sand with highly pure coke.   Second generation cells require cadmium telluride or copper indium gallium selenide.  

Third generation cells use gallium indium phosphide (GaInP), gallium arsenide (GaAs), or germanium (Ge).  All of these are used in small amounts (a square meter of CdTe contains approximately the same amount of Cd as a single C cell nickel-cadmium battery, in a more stable and less soluble form).

The silica is generally made from high purity glass sand that has been washed and processed to remove iron and other non-silica materials.

Most of the remaining materials are byproduct production from lead, zinc and copper. With gallium being a bauxite byproduct.

Cadmium is generally recovered from zinc ores and concentrates. Sphalerite, the most economically significant zinc mineral, commonly contains minor amounts of cadmium, which shares certain similar chemical properties with zinc and often substitutes for zinc in the sphalerite crystal lattice. The cadmium mineral greenockite is frequently associated with weathered sphalerite and wurtzite.

Gallium occurs in very small concentrations in ores of other metals. Most gallium is produced as a byproduct of processing bauxite, and the remainder is produced from zinc-processing residues. Only a portion of the gallium present in bauxite and zinc ores is recoverable, and the factors controlling the recovery are proprietary.

The available resources of germanium are associated with certain zinc and lead-zinc-copper sulfide ores.

Indium is most commonly recovered from the zinc-sulfide ore mineral sphalerite. The indium content of zinc deposits from which it is recovered ranges from less than 1 part per million to 100 parts per million.

Reserves for selenium are based on identified copper deposits and average selenium content.

 More than 90% of tellurium has been produced from anode slimes collected from electrolytic copper refining, and the remainder was derived from skimmings at lead refineries and from flue dusts and gases generated during the smelting of bismuth, copper, and lead-zinc ores.

 More than 90% of tellurium has been produced from anode slimes collected from electrolytic copper refining, and the remainder was derived from skimming at lead refineries and from flue dusts and gases generated during the smelting of bismuth, copper, and lead-zinc ores.