Keywords: ore, enrichment, flotation, cavitation, tailings storage.
The earth’s crust has a rather complex composition. This composition,
including as minerals, in the form of ores, includes ferrous and non-ferrous
metals. It is impossible to underestimate the presence of ores, because in the
process of life, we constantly, daily, hourly work with things that contain
various metals, ferrous, and non-ferrous. They are, perhaps, in more than 90%
of the household products around us, production tools, transport, equipment, etc.
The ore in its natural state is not suitable for direct metallurgical
processing due to its low iron content and high waste rock content. Smelting
low-concentration ore leads to the formation of a large amount of slag, which
naturally entails an increase in production costs. An increase in the concentration
of metals in ores has a significant economic effect. This is achieved through
enrichment.
Enrichment is an operation that increases the concentration of a useful
element (iron, manganese, etc.) by removing the maximum possible amount
of waste rock. Sometimes, when enriching ore with waste rock, part of the
harmful impurities is removed.
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Beneficiation is a mechanical process of separating ore particles that
represent either a useful mineral or waste rock. To do this, use differences
in any differing properties of the useful mineral and waste rock: density,
wettability, color, gloss, hardness, optical, electrical, magnetic, and other
properties.
Today there are many methods of ore beneficiation: gravitational,
magnetic, electric, special. The flotation method, as the most versatile, is used
in the enrichment of sulfur, gold (processing of gold-bearing ores), coal
(enrichment of coal sludge), iron ores, and non-ferrous metal ores. Also,
flotation is used in tailings processing.
Flotation is a method of mineral processing in industrial plants. This
method is based on the ability of some particles - hydrophilic - to be easily wetted
with a liquid and separated from other particles - hydrophobic. The process
takes place in a liquid medium, which is aerated with air or into which oil
droplets are introduced.
The separation of ore into elements occurs at the border of two different
means. In a flotation unit, hydrophobic particles adhere to gas or oil bubbles
and rise to the surface, while hydrophilic elements settle to the bottom of the
vessel. One part of the raw material goes into the foam product; the other part
of the raw material remains in the pulp. If minerals remain in the froth product,
flotation is called direct flotation. And if waste rock goes into the foam
product, the process is called reverse. In addition to water, other substances
can be used as flotation liquid.
There are four different flotation methods:
Oil. It is used for the extraction of sulfide minerals. Minerals are
wetted with oil in the ore and float to the surface of the water, and waste rock
settles down.
Film. The principle of operation of this equipment is based on the
ability of small hydrophobic particles to adhere to the surface of the water.
Electro-flotation. Particles rise to the surface of the liquid due to the
release of electrolytic gases in the liquid.
Foam. In installations, small air bubbles are passed through the
mixture of ore in water, which float to the surface and are collected from it.
The work of both young and venerable scientists is devoted to the study
and improvement of the technology of enrichment of various ores by the
flotation method. In particular, much attention is paid to this problem by the
staff of the Department of Processing and Processing of Mineral Resources
and Technogenic Raw Materials of the National Research Technological
University (or NRTU) ‘MIS&S’. A technique has been modeled for increasing
the quality of the concentrate by a factor of 2-3 for separate flotation of sands
and sludge in comparison with the standard scheme by capturing mineral
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