Surely in the future the mankind will exploit the mineral resources of the Moon and other planets of our Solar System but, you know, to ensure the success of a mineral exploitation and exploration must be made before.
So, there is a question: the mineral deposits of, say, the Moon, have been already explored?
The deposits have been delineated and sampled, the resources have been measured by means of extensive drilling, feasibility studies have been made as to have proved reserves?
There exists enough information as to give to a mining company the sufficient level of confidence to begin a profitable exploitation?
I repeat, surely the mankind will exploit the mineral resources outside our planet, but I think it will occur on a far future… Without exploration, without the job of field geologists the mining operations are a nonsense, very risky and usually leading to the huge economic losses.
Today the idea of mining in space belongs to science fiction, but again, it will be possible in a far future.
Most of the more than 2,000 known asteroids are in elliptical heliocentric orbits with perihelions outside the orbit of Mars and aphelions inside the orbit of Jupiter. The 22 named Trojan asteroids are in orbit around the (L-4 and L-5) Lagrangian points in Jupiter’s orbit 60° ahead and behind the planet. There are also a few asteroids hown beyond the orbit of Jupiter. The asteroids of most immediate interest are about fifty tiny bodies (0.5 to 23 km diameter) that approach the Earth. The earth-approaching asteroids are in orbits that allow them to pass near 1 AU. They are grouped in three classes based on the relation of their orbit’s semi-major axis to that of the earth’s. Exec known classes of earth-approaching asteroids are: Aten asteroids with semi-major axis less than 1.0 AU, Apollo asteroids with semi-major axis equal to or greater than 1.0 AU, and Amor asteroids with perihelia between 1.0 AU and 1.3 AU. Shoemaker et al. (1979) estimate the total population of earth approaching asteroids with visual magnitudes greater than 18 to be about 1300, of which 8 % are Xtend, 50 % are ~~0110s and 40 % are Amors. The only physical samples of extraterrestrial materials are the lunar samples and meteorites. Meteorites are a sampling of fragments of asteroids and comets. However, mtil asteroids are sampled directly, these are the best physical sample of asteroidal materials that we possess.
Meteorites are a biased sampling of fragments of asteroids and comets. One of the biases is relative resistance to fragmentation during atmospheric entry. An overriding bias is the time and place of fragmentation of a parent body. Another is the varying degree of resistance to weathering once meteorites have impacted the earth.
Two broad general classes of meteorites are the chondrites and the achondrites. Chondrites represent relatively unfractionated bodies and possibly the crust of fractionated bodies. Achondrites, which include the irons, are the result of fractionation in relatively large bodies by melting and gravitational separation of mineral phases. Achondrites resemble terrestrial rocks more closely than do chondrites, except for the irons and stony irons which are more closely related to the earth’s core and mantle.
The fractionated meteorites are represented by the nickel-iron meteorites, mesosiderites (pyroxene-plagioclase s tony-irons 1, pallasites (olivine stony-irons), siderophores (bronzite-tridymite stony-irons 1, lodranites (bronzite-olivine stony-irons 1, enstatite achondrites (aubrites) , hypersthene chondrites (diogenites) , olivine achondrites (chassignites) , olivine-pigeonite achondrites (ureilites 1, augite achondrites (angrites) , diopside-olivine chondrites (nakhlites) , pyroxène-plagioclase achondrites (eucrites and howardites) . Of the achondrites only the nickel-irons have significant quantities of precious metals. The stony achondrites tend to be devoid of native siderophile elements such as iron, cobalt, nickel and the platinum group metals. This is the result of gravity concentration of metallic siderophile elements in the NiFe core of a planetary body by magmatic fractionation. Therefore the NiFe contains most of the precious metals. The relative precious metal content of medium octahedrite iron meteorites, which is characteristic of the iron fraction of mesosiderites and some E and H-type chondritic stony meteorites.
Leaching (Gold-Silver/Copper or Others) in Tanks or Heap
Electrowinning and Smelting
Thickening & Filtering / Tailings & Water Treatment
Laboratory & General Mineral Processing
Crushing & Screening
Feeders and Conveyors
Flowsheets & Flowcharts
Maintenance & Mechanical
Pumps and Pumping
Reagents and Chemicals
Tools of a Metallurgist
Chondrites represent 80 X of meteorite falls. See Figure 2. They are unfractionated to poorly fractionated aggregates of chondrules (spheroidal mineral aggregates) in a fine grained to amorphous groundmass. Chondrites are grouped according to the free metallic NiFe present, ranging from highest to lowest as follows: ens tatite (El, high iron (81, low iron (L), very low iron (IL) and carbonaceous (CV, CO, 0.1 and CI). statite chondrites are broken into several types as follows:
Types E3 and E4 (clinoenstatite), and Types E5 and E6 (orthoenstatite. A11 chondrites are subdivided on a scale of from 1 to 6 according to the degree of chondrite development. Type C1 carbonaceous chondrites have no chondrules while L6 chondrites are mostly well developed chondrules in a microcrystalline, grounds . Interesting chondritic asteroids are Gl and CV carbonaceous chondrites and ordinary chondrites with low,metal contents such as the L and LL chondrites. Nearly all chondrites contain almost equal values of precious metal. The metal fraction of the low metal content chondrites have a high precious metal content because the precious metals, being mainly siderophile, are contaminated with less NiFe. The metal fraction of the institutes has a 24 X chance of having more than 30 ppm iridium. The metal fraction of Types L, LL, CO and CV chondrites have the highest percentage of precious metals. In these meteorites the Ni-Fe fraction is mostly taenite, ranging from less than 1% to nearly 10% by weight. The Types L and LI. (hypersthene-olivine) chondrites, Types CO, CV carbonaceous and LL (olivine-pigeonite) chondrites and Types CO and CV carbonaceous chondrites contain taenite as the predominant metal fraction.