Volume 02 Issue 05-2022
35
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
05
Pages:
35-39
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
ABSTRACT
The article investigates the liquid extraction of valuable and rare metals from dumps of mining and metallurgical plants
in an extractor with an increased contact time. The design, and the principle of operation of a bubbler extractor with
an increased contact time based on pneumatic mixing are studied. The hydrodynamic parameters of continuous
extraction without loss of valuable metals in the apparatus are studied.
KEYWORDS
Bubbling, continuous operation, liquid extraction, rare metals, increased contact time, energy consumption.
INTRODUCTION
When extracting heavy, rare, trace and noble metals by
hydrometallurgy methods, the fundamental criteria for
choosing the type of extraction apparatus are low
specific energy consumption for the extraction
process, as well as providing it with the required
contact time of the reacting liquids for the process [1].
Liquid extractors with pneumatic agitation or bubbling
extractors fully meet these requirements. In terms of
specific energy costs for the extraction process, such
devices consume up to 3.5–4.0 less electrical energy
Research Article
EXTRACTION OF RARE METALS FROM MINING DUMPS IN BUBBLING
EXTRACTORS
Submission Date:
May 01, 2022,
Accepted Date:
May 10, 2022,
Published Date:
May 22, 2022
Crossref doi:
https://doi.org/10.37547/ajast/Volume02Issue05-07
Khursanov B.J.
Senior lecturer, Fergana Polytechnic Institute, Republic of Uzbekistan, Fergana
Journal
Website:
https://theusajournals.
com/index.php/ajast
Copyright:
Original
content from this work
may be used under the
terms of the creative
commons
attributes
4.0 licence.
Volume 02 Issue 05-2022
36
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
05
Pages:
35-39
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
compared to extractors in which liquids are mixed
using various agitators [2,3].
The second condition for ensuring a sufficiently long
contact time of the reacting liquids for the most
complete extraction of the target component, from
our point of view, is fully met by the design of a
multistage bubbling extractor developed by us with an
increased phase contact time [4].
The device and principle of operation of a multi-stage
bubbling extractor is shown in fig. one.
THE MAIN PART
The multi-stage bubbling extractor includes a vertical
housing 1, divided by partitions 2 into separate settling
sections. On the partitions between the inner 3 and
outer 4 nozzles of the mixing device are additional
inner (odd) 5 and outer (even) 6 concentric nozzles.
The inner branch pipe 5 is fixed in the web of the upper
partition of the settling tank section and is located with
a gap to the lower partition of the settling tank section.
The outer branch pipe 6 is fixed in the web of the lower
partition of the sump section and is located with a gap
to the upper partition of the sump section. In the lower
part of the inner pipe 3 of the mixing device, there is a
gas distribution nozzle 7 with holes 8 in the sidewall.
Overflow tubes 9 for heavy liquids are also attached to
the partition wall 2,
Fif. 1. Multi-stage bubble extractor
The extractor works as follows. Light liquid through
the lower section of the gas distribution nozzle 7
enters the inside of pipe 3. Therethrough the holes 10
of the overflow tubes 9, heavy liquid flows from the
settling part of the overlying settling section. With the
Volume 02 Issue 05-2022
37
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
05
Pages:
35-39
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
joint movement of a mixture of liquids from bottom to
top inside nozzle 3, then from top to bottom between
nozzles 3 and 5, then from bottom to top between
nozzles 5 and 6, and finally, from top to bottom
between nozzles 4 and 6, the liquids are intensively
mixed by bubbling inert gas that enters nozzle 3
through holes 8 of gas distribution nozzles 7. In the
upper part of the space between nozzles 5 and 6, gas
bubbles are separated from the mixture of liquids and
the gas enters the gap between the upper partition of
the settling tank section and the uppercut of the pipe
4, from where it enters the mixing devices of the
overlying settling section. The mixture of liquids exits
between nozzles 4 and 6 into the settling part of the
settling section,
Overlapping the upper sections of the overflow tubes
9 with caps 11 with slots 12 in the lower part ensures
that only completely settled heavy liquid enters the
tubes 9. Holes 13 are used to release air from the caps
11 when filling the extractor with liquids before
starting.
By installing any even number of additional concentric
pipes between nozzles 3 and 4, each odd of which,
starting from the innermost one, is installed with a gap
to the lower partition of the section, and each even
number - with a gap to the upper partition of the
section, it is possible to provide any necessary contact
time of the reacting liquids.
The normal operation of the extractor will be ensured
when the annular channels between nozzles 3 and 5, as
well as 4 and 6, will have such a cross-section at which
the velocity of the mixture of liquids there will be a
greater rate of ascent of gas bubbles in a mixture of
liquids.
Experiments to establish the main hydrodynamic
parameters of the apparatus, as well as the efficiency
of mass transfer processes, were carried out by us in a
laboratory setup, the scheme of which is shown in fig.
2.
The mixing zones of the extractor model glass shells 4,
14 and 15, through which it is possible to visually
observe the processes occurring in them (crushing of
drops of the dispersed phase, the behaviour of air
bubbles for mixing, etc. The light phase, the flow rate
of which is controlled by the rotameter 7 and valve 6,
is fed into the apparatus from the LF tank using pump
2, and the heavy phase, the flow rate of which is
regulated by rotameter 15 and valve 13, comes from the
TF tank through holes in the lower end of tube 10.
When the phases move together from bottom to top
inside shell 4, from top to bottom inside shell 14 and
from bottom to top inside the shell 15, the liquids are
intensively mixed by the inert gas supplied from the
blower 28, and the flow rate of which is regulated by
the rotameter 9 and the valve 8. The mixture of liquids
after the apparatus is collected in the TF tank. The
mixture of liquids is separated into light and heavy
phases in tank 31, in which inert gas is also separated
from liquids, which are removed from the installation
through pipe 16.
To determine the true size of the dispersed phase
droplets and gas bubbles, a camera 22 is used, and the
level of liquids stratifying in tank 31 is controlled using
a level gauge 17 to control the flow of heavy liquid into
the tank 30 by valve 29.
Volume 02 Issue 05-2022
38
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
05
Pages:
35-39
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
Fig. 2. The main hydrodynamic indicators of the device
On this installation, experiments were carried out to
determine many of the hydrodynamic parameters of a
multi-stage bubbling extractor. The rate of outflow of
a heavy liquid into a mixture of liquids and gas through
the holes of the tube can be calculated using the
following equation[5]:
1
2
2
см
Т
Т
h
g
,
(1)
where
cm
- density of the mixture of light and heavy
liquids, kg/m3;
- volumetric gas content;
T
- density of heavy liquid, kg/m3;
- coefficient of resistance of the hole in the tube 10.
Since for a specific liquid system, all quantities included
in (1) will be constant, except for
, then the
performance of the extractor for a heavy liquid
depends precisely on the gas content
.
With the co-current motion of liquid and inert gas, the
volumetric gas content is determined from the
dependence [6]:
пар
= (1 – 0,04ω
ж
) · φ
1
,
(2)
and with countercurrent movement of liquid and inert
gas, the volumetric gas content can be determined
from the dependence:
ωg against = (1 + 0.04ωl ) φ1 , (3)
where ωl is the reduced fluid velocity, m/s;
φ1
is the gas content in a stationary liquid.
To calculate φ1, it is proposed empirical equation:
φ1 = 2.47 ωg0.97 , (4)
where
ωg -
reduced gas velocity in the mixing zone,
m/s.
CONCLUSION
The mixing of immiscible liquids was carried out in a
zigzag mixing zone. This will increase the time of
intensive mixing and increase the efficiency of the
extraction process. Volumetric parameters of gas in
the design of the apparatus, therefore, the dimensions
of the zones of the apparatus are determined
Volume 02 Issue 05-2022
39
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
05
Pages:
35-39
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
depending on them. As a result of the scientific
research carried out, equations were derived for
determining the gas content and velocity in the mixing
zone in the newly created apparatus.
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1.
Алиматов, Б. А. (2003). Развитие научно-
технических
основ
конструирования
жидкостных
экстракторов
с
пневмоперемешиванием: дис.… д-ра техн.
наук. Автореф. дисс… д. т. н. Ташкент, ТГТУ.
2.
Садуллаев Х.М., Матбабаев Д.М., Алиматов
Б.А.,Хурсанов Б.Ж. (2003). К затратам энергии
на
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жидкостей
в
экстракционной установке с барботажным
экстрактором. НТЖ ФерПИ, Scientific-technical
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3.
Алиматов Б.А.,Хурсанов Б.Ж. и др. Затраты
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перемешивании
несмешивающихся
жидкостей// Вестник БГТУ им. В.Г.Шухова. 2011,
№ 3. c. 111-112.
4.
Алиматов
Б.А.,
Хурсанов
Б.Ж.
Многоступенчатый барботажный экстрактор.
Патент РФ № 2658053, кл. В01д11/04. 2018 г.
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Алиматов Б.А., Соколов В.Н., Хурсанов Б.Ж.
(2001).
Влияние
газосодержания
на
производительность
барботажного
экстрактора по тяжелой жидкости. НТЖ ФерПИ,
Scientific-technical journal (STJ FerPI), № 2. c. 93-
94.
6.
Шендеров, Л. З., & Дильман, В. В. (1988).
Движение газа в барботажных реакторах.
Теоретические основы химической технологии,
(4), 496-510.
