Sofremines-François Colette, copper métallurgical expert
page 1
During our mission, we experienced a number of difficulties due to transportation
problems and to the attitude of Balkhasmed management staff .We did not feel to be
welcome on the site of the complex. A great deal of time was lost in unsuccessful
attempts to arrange meetings with managers, walking through sections of the plant
without appropriate assistance nor presence of operations supervisory personnel. We met
only one section manager and the director of the copper transformation plant. In total, we
spent two and half days on the site of the complex.
The general manager does not seem to agree with the privatisation of the company
nor does he seem to agree with the objective of involving of a foreign investor. Despite
this general impression, the director designated by Balkhashmed to be responsible for the
privatisation process, gave us his support and all the information that we collected. The
following descriptions and the flow sheet of the metallurgical process have been
elaborated.
1.
CONCENTRATE SECTION
METALLURGICAL EXPERT'S MISSION
TO BALKHASHMED
This section includes:
The unloading of rail wagons delivering concentrates to the plant.
The storage areas of these concentrates before the charge preparation.
The filtration of Balkhashmed concentrates and, sometimes, of the Mongolian
concentrates (In winter, Mongolian concentrates are frozen and they have to be
re-pulped). This filtration is done by vacuum disk filters.
Two drying rotary furnaces reduce concentrate moisture from 12-14 % to 4 %.
STORAGE AND CHARGE PREPARATION AREAS FOR THE SMELTERS.
This section is also in charge of the storage of external copper raw materials (copper
scrap, blister copper, waste..), coal (klinker?) and fluxes (pyrites, silica, lime, etc.).
STRUCTURE OF COPPER SUPPLIES
In 1994, more than ten sorts of concentrate were handled in this section. The
distribution of these sources is the following:
Sofremines-François Colette, copper métallurgical expert
 Balkhashmed
23.7%;
 Kazak concentrate
15.4%;
page 2
 Kazak blister copper 15.0%;
 Mongolian concentrate 36.7%;
 Chilian concentrate
7.2%;
 other sources (nominal, balance).
2.
SMELTING SECTIONS
2.1.
VANJUKOV FURNACE
The Vanjukov or "smelt-in-melt" process, belongs to the "bath smelting" family of
copper smelting processes. In this family, reactions occur in the molten bath of the
furnace. Concentrates and fluxes (plus coal and pyrites), are charged into the bath of the
fixed hearth furnace. The latter is equipped with tuyeres through which oxygen enriched
air is injected into the slag layer. This process has generally been applied to low grade
concentrates (10-15% Cu); it seems to be well suited for high slag forming, copper
smelting operations. The operation is almost autogenous in energy and the gases
generated are suitable for sulphuric acid production. The productivity per square meter of
furnace is forty times higher than in a conventional reverbatory smelter. The capacity of
this Vanjukov furnace is 53 t/h of Cu concentrates (12.5% Cu) or 6.5 t cu/h. At an 85%
utilisation rate, this furnace can process 400 000t of concentrates/year which corresponds
to a production of 44 000 t Cu, in matte.
Vanjukov data operating data:
concentrates t Cu (a)
% Cu
matte produced t Cu (b)
% Cu
slags t Cu
% Cu
Cu entrained in gases t Cu
balance t Cu
yield mattes % b/a
hours operation
t Cu/hour operation
% operating hours
capacity 330 days 85% utilisation rate
1991
28 137
11.6%
25 907
43.5%
1 647
1.26%
189
394
92.1%
4 318
6.00
49.3%
44 000
1992
9 307
13.3%
8 480
43.9%
360
1.72%
106
361
91.1%
1 424
5.96
16.3%
44 000
1993 1994 (6 months)
40 700
11 701
15.0%
12.3%
37 434
10 627
44.9%
42.9%
1 580
773
0.83%
1.20%
390
131
1 296
170
92.0%
90.8%
6 080
1 850
6.16
5.74
69.4%
42.2%
44 000
44 000
comments:
High Cu grade in the slag, except in 1993. In a conventional reverbatory furnace, the
Cu content of the slag is normally 0.68 %.
Sofremines-François Colette, copper métallurgical expert
page 3
The utilisation rate of the furnace is low, due to the fact that the sulphuric acid plant
is not running. The copper recovery rate would be higher if the sulfuric acid plant was
more effective and the furnace utilisation rate was higher.
Sofremines-François Colette, copper métallurgical expert
2.2.
page 4
REVERBATORY SMELTERS
Reverbatory smelting is still used, despite its high energy consumption. In
Balkhashmed, the reverbatory smelters supplied 70 % of copper in matte. lt is a
conventional design without major improvement. Two identical furnaces are used in this
section.
Reverbatory operating Data
total feed material t Cu (a)
% Cu
matte produced t Cu (b)
% Cu
slag t Cu
% Cu
ash t Cu
% Cu
Cu entrained in gases t Cu
balance t Cu
balance % of total feed
fresh feed t Cu
% Cu
recycled feed t Cu
% Cu
yield mattes % b/a
hours operation
t Cu/hour operation
% utilisation
capacity 330 days
1991
70 023
10.0%
66 567
26.4%
2 258
0.63%
286
6.35%
1 213
-301
-0.4%
65 086
14.20%
4 937
2.04%
95.1%
4 318
1992
68 912
10.9%
64 860
30.8%
2 053
0.77%
373
5.40%
770
856
1.2%
64 789
15.00%
4 125
2.90%
94.1%
1 424
45.55
16.3%
356 400
1993 1994 (6 months)
42 490
90 261
11.7%
11.7%
40 776
85 799
27.5%
29.2%
1 432
2 645
0.61%
0.63%
55
198
6.10%
5.70%
226
664
1
955
0.0%
1.1%
40 081
85 799
16.70%
15.80%
2 409
4 462
1.90%
1.90%
96.0%
95.1%
1 850
6 080
22.04
14.11
42.2%
69.4%
356 400
356 400
Comments
Low Cu% slag is recycled in this furnace after concentration in the ore concentration
plant (line N°7).
The reported yields (98%) are too high, in our opinion. In this type of furnace, yields
are of the order of 93 %.
The utilisation rates of these two furnaces are correct.
2.3.
CONVERTERS
Three converters are in operation out of five converters installed. They operate
according to normal and classical procedures. They are fed by the Vanjukov and
reverbatory matte furnaces. The gas recovery system is not operative. A great amount of
SO2 gases is released into the atmosphere, in this section of the metallurgical complex.
Sofremines-François Colette, copper métallurgical expert
page 5
Blister Balance (from the conentrate preparation plant to blister copper stage)
concentrates Balkhashmed t Cu
% Cu
external concentrates t Cu
% Cu
total concentrates t Cu
% Cu
copper cement (leaching) t Cu
% Cu
other supplies t Cu (scrap, slags, waste etc.)
% Cu
total copper supply t Cu
% Cu
Vanjukov
reverbatories
total
total losses t Cu of which
Vanjukov slags
Cu entrained in gases Vanjukov
balance Cu Vanjukov
reverberatory slags
ash reverbatories
Cu entrained in gases reverbatories
balance Cu reverbatories
balance blister
blister copper produced
% Cu
rate of recovery %
1991
36 398
14.8%
49 501
16.9%
85 899
15.9%
3 108
37.90%
1 649
6.35%
90 656
15.82%
28 137
70 023
98 160
5 833
1 647
189
394
2 258
286
1 213
-301
147
84 823
98.75%
93.57%
1992
30 622
14.0%
69 680
19.7%
100 302
17.5%
3 505
25.50%
1 449
5.40%
105 256
17.17%
9 307
68 912
78 219
5 750
360
106
361
2 053
373
770
856
871
99 506
98.72%
94.54%
1993 1994 (6 months)
31 460
14 492
14.1%
14.1%
70 374
34 031
20.8%
26.6%
101 834
48 523
18.1%
21.0%
15 349
35.90%
1 538
825
5.70%
6.10%
118 721
49 348
18.81%
20.20%
40 700
11 701
90 261
42 490
130 961
54 191
5 031
2 704
1 580
773
390
131
1 296
170
2 645
1 432
198
55
664
226
955
1
-2 697
-84
113 690
46 644
98.80%
98.82%
95.76%
94.52%
comments:
Here as we already said, reported yields are certainly too high (this is due to the
manner the materials are measured). A yield of about 93 % is normally reached. Material
losses in the gases are not measured. We were told that concentrate feed, slags and dusts
are measured and controlled (in tonnes and Cu %), but Cu losses in the gases are
calculated by sub-traction, assuming 100% copper balance. In 1991, the percentage of
Balkhashmed's concentrates in the feed was 40%, in 1992 29%, in 1993 26.5% and in
1994 29.4%.
2.4.
DATA ON FLUXES
total feed (a) dry tonnes
of which pyrites
of which other fluxes
total fluxes (b)
b/a %
1991
705 751
141858
2 360
144 218
20.43%
1992
749 031
124156
17 672
141 828
18.93%
1993 1994 (6 months)
763 757
321 660
94452
54685
54 300
31 657
148 752
86 342
19.48%
26.84%
Sofremines-François Colette, copper métallurgical expert
page 6
comments
Important quantities of pyrites are fed to the Vanjukov and reverbatory matte
furnaces. We do not know if these pyrites contain gold and silver and how much. Other
fluxes are lime and silica.
2.5.
PROCESS CONTROL
All the furnaces used for matte and blister production are controlled from a central
control room. All devices controlling the physical parameters (temperature, material
flows, gas flows, oxygen and pressure) are installed. The dispatcher follows the process
on video screens, which indicate, in real time, on flow sheets, the state and evolution of
all process and operating parameters. The results of chemical analyses of the different
outputs (matte, blister, slags), are communicated by phone every hour to the control room,
by the central laboratory.
Anode furnaces (thermal refining furnaces):
There are three reverbatory furnaces in this section. These furnaces are fed by
Balhkashmed's blister copper, blister copper from Kazakhstan and recycled copper
products of the plant e.g.anodes, rejected cathodes and copper scrap. Due to the lack of
wood used as reductant, they have had to suppress poling. Consequently, quality is
reduced from 99.4% Cu to 94.1% Cu. The major impurities are Ni, Pb, As and Zn. Nickel
grade is 3 % in the Kazak concentrates. Anode aspect is quite correct, they are flat and
smooth. After quality control, 1.5% of the production is refused and recycled. lt is not
possible, through the figures we received, to know the exact production capacity of these
furnaces. For 300 000 t of refined copper per year, they have to produce 380 000 t of
anodes. ln 1994,the utilisation rate of the three furnaces was 80 %, for a reported
production of 132 000 tons of anodes.
Anode furnaces data
Balkhashmed blister t Cu
external blister t Cu
recycled anodes t Cu (a)
rejected anodes (quality control) t Cu (b)
other sources t Cu
total copper supply (c)
production of good anodes (d)
anode recycling a/d %
defective anodes b/c %
rate of recovery %
Balkhashmed blister % of total supply
1991
84 921
37 156
32 236
2 972
1 179
158 464
153 478
21.00%
1.88%
96.9%
53.6%
1992
99 506
27 013
28 581
2 911
8 457
166 468
161 686
17.68%
1.75%
97.1%
59.8%
1993 1994 (6 months)
113 620
46 644
20 921
7 781
33 102
11 233
2 654
935
6 492
1 146
176 789
67 739
171 065
65 997
19.35%
17.02%
1.50%
1.38%
96.8%
97.4%
64.3%
68.9%
Sofremines-François Colette, copper métallurgical expert
page 7
Comments:
Despite good anode quality, recycled anodes range from between 21 and 17 %, as
compared to a 14% planned figure. The quantity of Kazak blister supply, from Irtych rare
metals plant near Ust Kamenogorsk, is seen to decrease from 37 156 t Cu in 1991, to an
estimated 15 500 t Cu for 1994.
3.
ELECTRO-REFINING
For this section we were not given any written information. We only received verbal
information.
The production capacity of this plant is 300 000 t Cu per year. The starting sheets
section is in good condition, the sheets are smooth and straight. The utilisation rate of the
sheets produced is excellent, 95 %. Anode cycle is 21 days and cathode cycle 7 days.
Current density is 213 A/m3 compared to a design value of 220 A/m3. Current efficiency
is 92 % for a nominal value of 94 %.
Electrolyte composition is:
 Cu 40-45 g/l,
 Ni 20-30 gr/1,
 As 10-20 gr/1,
 Sb 1-1.2 gr/1,
 H2S04 100-200 gr/1.
The high grade of nickel is one of the problems that Balkhasmed have to solve.
Nickel is eliminated, as of today, by bleeding toward the production section of copper
sulphate. In general, the aspect of the cathodes is good, except for some defects on the
bottom. These defects are due to the high level of slimes and can be eliminated simply by
improving visual controls in this section. 70% of the production is MOK. The slimes
which contain gold and silver, are treated in a plant for concentrating gold and silver
residues. The copper residue is sent back to Balkhashmed and recycled in the
metallurgical complex. A new plant to treat gold and silver concentrate residues, is
presently being built for Balkhashmed, by Boliden Contech of Sweden. In 1995, the
Boliden plant will be completed and the slimes will be treated by Balkhashmed, up to the
stage of gold and silver doré.
4.
ACID PLANT
No visit, no informations and no management contact. Production in 1989 was
236 000 t. In 1994, they hope to produce 100 000 t of acid. Production has been affected
by the decrease of copper production, and more importantly by the fact that traditional
Sofremines-François Colette, copper métallurgical expert
page 8
users (uranium leaching) have drastically reduced demand. This is creating great
environmental problems in the area. To mitigate these problems, Balkhshmed have
several projects. Two projects are to increase utilisation of sulphuric acid, by setting up:
–
a leaching plant for treating low grade copper ores and oxides (25 000t/year of acid)
–
an ammonium sulfate fertiliser plant.
Another project is to improve the recovery of gases in the metallurgical plant, mainly
in the converters area.
5.
5.1.
STATE OF THE COMPLEX
CONCENTRATE PREPARATION AND DRYING.
The filtration and drying plant and equipments are in very bad state of maintenance.
Balkhashmed have a project to replace the disk filters by ceramic filters. These filters are
already on site but still in their containers. They have to be installed and put into service.
The belt conveyors, the storage area equipement (reclaimers), show evidence of a lack of
maintenance of some two or three years.
5.2.
SMELTERS, CONVERTERS AND ANODE FURNACES
Excepting some leaks of gases, the state of all the furnaces seems to be quite good
and the dispatching room is well maintained. We believe that the main problem is a lack
of maintenance of the building and in the gas recovery system. Balkhashmed plan to
replace the heat exchanger of the Vanjukov furnace at a capital expense of
26 US$ million.
5.3.
ELECTROREFINING.
The maintenance schedule is to replace 15% of the cells each year. Our point of vue
is that there is a maintenance backlog of three years, for the cells. The silicium converters
are well maintained and the maintenance backlog for building is also about three years.
5.4.
ACID PLANT
This is the area of main concern for the immediate future.
5.5.
TRANSFORMATION PLANT
The copper transformation plant is under modernisation.
Sofremines-François Colette, copper métallurgical expert
5.6.
page 9
DUMP LEACHING
Balkhashmed and a private american company, Earth Resources (ER), have set up a
joint venture to recover and valuate copper from the Kounrad low grade and oxide ores.
The ownership distribution of this JV is 60% Balkhasmed and 40% ER. ER is to provide
technology, engineering skill and capital funds for the acquisition of plant and equipment.
Balkhasmed is to provide only funds. The copper reserve in low grade ores is reportedly
112 300 t Cu at a grade of <0.5 % Cu. They intend to use the leach in dump process, with
solvent extraction and electrowinning (SX/EW). The main design data are the following:
 Rate of recovery 63%
 Yearly production 5 000 t of electrowon copper
 Capacity 10 000 tons (due to the fact that the plant will operate only six months in the summer
season).
 Acid consumption 5 tons per ton of refined copper produced.
 Dump capacity 2 000 000 t of ore.
 Four dumps will be used after the starting time.
Acid consumption is important and if the cost of acid is valuated at market price, it
means a cost of 0.30 US$/lb Cu. Operating costs in dump or heap leaching plants, vary
between 0.15 US$/lb and 0.35US$/lb Cu.
The profitabily of this JV will depend mainly on the acid cost and on the copper in
are cost. This plant will consume 25 000 tons of sulfuric acid per year, but only in the
summer season.
Alternatively, Balkhashmed has treated in the past, this low grade ore with a
dump-leach process, followed by copper cementation. Copper cement could be smelted
into 94.5% Cu in a low cost shaft furnace, and fed to the anode furnaces of the plant,
thereby contributing to the copper supply.
5.7.
TRANSFORMATION PLANT
This plant was built during the second world war with Russian second hand
equipment. The equipments are used to produce pure copper, monel, brass and bronze
products. They are able to produce a large range of transformed products in each sort of
copper and copper alloys. The main products are strips, bars, wires and sheets. The
production level depends on product specifications. It is around 40 000 t/year.
At present, Balkhashmed lacks of inputs i.e. metals for production of alloys. Ni, Sn
and Zn are all imported. Due to the non availability of hard currencies, imports are
impossible today. Consequently Balkhashmed presently produces only copper
transformed products. They are building a new plant with new and modern equipment. To
Sofremines-François Colette, copper métallurgical expert
page 10
complete this plant Balkhashmed need 30 US$ million in addition to the 100 US$ million
that has already been invested. The main equipments in this new plant are:
 Two Austrian furnaces
 One russian furnace with continuous casting equipment
 A wire machine able to produce thin wire (minimum 0.15mm)
 Contirod installation, Enamel coating equipement for magnet wire.
The production capacity will be between 70 000 t for rolled products (copper and
copper alloy strips and bars), 40 000 t of wire bars and 7 000-8 000 t of magnet wire.
They intend in this new plant to reduce the personnel from 1 300 people to 900 people.
6.
CONCLUSIONS
The major problem of this complex is the copper supply, in quantity and grade of
concentrates, and blister.
 The structure of copper supplies in 1994 is shown on the table below:
1994 production level
blister 92 000t
Kazak blister
nominal capacity level
cathodes 132 000t
blister 200 000t
15.0%
cathodes 300 000t
6.6%
Kazak concentrates
18.5%
15.4%
8.7%
6.7%
Balkhasmed concentrates
28.4%
23.7%
13.3%
10.5%
Kazak supplies total
46.9%
54.1%
22.0%
23.8%
44.5%
36.7%
20.9%
16.0%
8.6%
7.2%
4.1%
3.1%
Mongolian concentrates
Chilean concentrates
scrap, waste, recycling, etc.
shortfall
total
2.0%
0.9%
0.0%
0.0%
53.0%
56.2%
100.0%
100.0%
100.0%
100.0%
The table shows an important shortfall in Kazak and Balkhashmed copper supplies.
The main suppliers of copper concentrates are external: Mongolian and Chilean, but they
are treated and refined, on custom basis. To achieve the highest value-added and profit for
Balkhasmed, it is necessary to maximize the feed of the plant with Kazak concentrates
and blister copper. At least, it would be desirable to involve the Mongolian company in
Balkhasmed's capital. Based on the present structure of copper supplies, it is net possible
to reach the nominal capacity of production. The new Bozshikul flotation plant has to be
started as soon as possible.
Sofremines-François Colette, copper métallurgical expert
page 11
 The overall rate of copper recovery of the complex, after correction, is of the
order of 93 %. With reference to other plants, this is fairly good and it reflects that
Balkhashmed is operating correctly despite the lack of maintenance which shows in many
of sections.
 The aspect and the quality of refined cathodes is good.
 In 1995 they will have the capacity to produce 100 000 tons/annum of copper
transformed products.
 The state of the plant is in fact not too bad. We believe it is possible to revamp it
without major difficulties. Moreover, core process units are little affected by degradation.
 We estimate that the replacement value of the metallurgical plant (value of a new
plant of the same capacity i.e. 300 000t refined Cu/annum), excluding mines and flotation
plant, is 900 US$ million. Considering a rate of 10% of the investment value for
maintenance expenses per year, revamping for a three years maintenance lack is of the
order of 270 US$ million. If the cost for revamping which is already planned by
Balkhashmed is added to this (Vanjukov furnace, filtration of concentrates, sulphuric acid
plant), the total expenditure of which is given for approx. 300 US$ million, there comes a
total revamping and rehabilitation cost of approx. 570 US$ million.
 Balkhashmed indicate that they have 200 000t/annum and 300 000t/annum
capacities for blister copper and electrolytically refined copper, respectively. We need
further figures and information to confirm the capacities of each furnace.
 The pollution problems need to be solved urgently. They have to repair and
modify the gas piping system as soon as posible. New customers for sulphuric acid have
to be found. Balkhashmed have to start as soon as possible fertilizer and low grade ore
leaching plants.
 We are not able to give recommendations and advice about personnel and cost.
The information we have received are not divided between mines, flotation and the
different metallurgical sections. Nevertheless one may assure that there are too many
employees in Balkhashmed, as compared to similar plants in the western world taken as
reference. There are 12 000 people employed in 1994, for a production which can
normally be, say 250 000-300 000 t/annum of refined copper. This means a productivity
of 20-25 t Cu/man year, while the international reference is 60 t Cu/man year.