currently, the quality of the ore and the consequent cost and mass of equipment required to extract it are unknown and can only be speculated. some economic analyses indicate that the cost of returning asteroidal materials to earth far outweighs their market value, and that asteroid mining will not attract private investment at current .
etymology and pronunciation. metallurgy derives from the ancient greek μεταλλουργός, metallourgós, 'worker in metal', from μέταλλον, métallon, 'mine, metal' ἔργον, érgon, 'work'.. the word was originally an alchemist's term for the extraction of metals from minerals, the ending -urgy signifying a process, especially manufacturing: it was discussed in this sense .
the advantages of hpal plants are that they are not as selective toward the type of ore minerals, grades and nature of mineralisation. the disadvantage is the energy required to heat the ore material and acid, and the wear and tear hot acid causes upon plant and equipment. higher energy costs demand higher ore grades. heap atmospheric leach
though successful in extracting gold-rich minerals, the widespread use of the process resulted in extensive environmental damage, such as increased flooding and erosion, and sediment blocking waterways and covering farm fields. these problems led to its legal regulation. hydraulic mining has been used in various forms around the world.
mining operations require special equipment to handle the extraction and processing of ore in outer space. the machinery will need to be anchored to the body, citation needed but once in place, the ore can be moved about more readily due to the lack of gravity. however, no techniques for refining ore in zero gravity currently exist.
this form of recovery is used extensively to increase oil extraction in the san joaquin valley, which yields a very heavy oil, yet accounts for ten percent of the united states' oil extraction. citation needed fire flooding in-situ burning is another form of teor, but instead of steam, some of the oil is burned to heat the surrounding oil.