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Notes
fodder фураж
poultry домашняя птица
lignite бурый уголь, лигнит
pros доводы за
cons (лат . contra) доводы против
livestock домашний скот
Text 34
BACTERIA-'METALLURGISTS'
When people cannot extract a required metal from an ore concentrate or ore
with the help of traditional technologies this work can be done by bacteria. They
do it both more effectively and efficiently.• The process is connected with the
oxidation by microorganisms of the sulphide of a required metal. A solution is
made from which the metal is extracted in a traditional way. The microbes are
able to process even the concentrates which formerly could not be processed.
The point is that bacteria put onto the concentrate find the very metal in the
mass they were meant for. No mechanical grinding whatever can separate, say,
copper sulphide and zin sulphide which are in a copper-zink concentrate. After
undergoing a pyrometallurgic processing an alloy is obtained. To separate it
L
sophisticated and expensive technology is needed. Whereas the bacteria, having
promptly found "their" mineral, first oxidize inо sulphide passing it into
solution. Then they set to working n the copper sulphide. If the process is
stopped when the zinc s in solution, then the copper can be melted out by a
traditional way. As to the zinc in solution, it can also be easily extracted.
Another example is connected with obtaining gold from a concentrate that
contains a harmful admixture - arsenic. By using well-known metallurgic
processes there is a possibility of letting arsenic go into the atmosphere. The
pernicious character of this method is quite evident, that is why such
concentrates are not ed. As to the minutest microorganisms, they can carry out
this task as well. They pass arsenic into solution by preliminary oxidizing it, and
gold is extracted traditionally.
Krasnoyarsk scientists are not engaged in biometallurgy itself, they are
interested in the microbiological aspect of the technology, to this affect growing
bacteria of various groups, verious stocks, teaching them to unmistakably
distinguish metals. The new branch of industry requires a great amount of
bacterial biomass. How can it be obtained?
A group of scientists-headed by scientist Gernnady Denisov e created
productive cultlvat6rs that are both easy to handle reliable. Such "plantations" of
bacteria are available for metallurgical industry. Practical experience shows that
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