654
P. Xin et al.
have a great significance on antimony smelting industry development in Guangxi if
an applicable and feasible technology of such antimony smelting slag treatment can
be utilized in the plant.
There are some smelting slag treatment technologies utilized in China at present,
which are rotary kiln process and fuming furnace process. Rotary kiln process is
widely utilized for zinc leaching residue treatment. The equipment and facilities of
rotary kiln process are easy to operate. However, zinc recovery is low when the low
zinc content slag is treated with rotary kiln process, because the effective contact area
between reductant and slag in rotary kiln is small, and the slag in rotary kiln is not
totally in molten. At the same time, a large amount of metallurgical coke is consumed
during the process, which will increase the operation cost [1]. Fuming furnace process
is a kind of molten bath smelting technology, and pulverized coal is utilized as
reductant. The pulverized coal and CO produced by pulverized coal combustion will
have reaction with metallic oxide in the molten bath. This technology can be utilized
to treat various raw materials and has high recovery of zinc and lead. Currently, this
technology has been widely utilized for the treatment of antimony smelting slag,
lead smelting slag, and zinc leaching residue. Based on research study on antimony
smelting slag and operation experiences, the fuming furnace process is utilized by
Guangxi Shengfu Antimony to treat such antimony smelting slag. The factory has
been in operation for two years. This paper introduces the actual production situation.
Finally, it is proved that Zn, Pb, and Sb are effectively recovered by fuming furnace
process after a period of operation. Therefore, the fuming furnace technology solves
the problem of antimony slag storage which containing Zn, Pb, and Sb and effectively
recovers the valuable resources as well.
Process Theory
Antimony smelting slag is produced from blast furnace during antimony oxides
reduction. The slag composition of such antimony smelting slag is FeO–SiO 2 –CaO,
and Pb, Zn, and Sb in slag appears as complicated oxides. In the antimony smelting
slag, part of Pb exists in the form of PbS. In the heating stage, PbS is oxidized into
oxide PbO, and a small part of PbO, ZnO, and Sb 2 O 3 volatilizes into dust. Most
lead, zinc, and antimony oxides in the slag will have reaction with pulverized coal
and CO produced from pulverized coal combustion to recover metals lead, zinc, and
antimony. The major chemical reaction in the molten bath is as follows [2] (Fig. 1):
C(s) + O 2 (g) = CO 2 (g)
2C(s) + O 2 (g) = 2CO(g)
ZnO(1) + CO(g) = Zn(1) + CO 2 (g)
P. Xin et al.
have a great significance on antimony smelting industry development in Guangxi if
an applicable and feasible technology of such antimony smelting slag treatment can
be utilized in the plant.
There are some smelting slag treatment technologies utilized in China at present,
which are rotary kiln process and fuming furnace process. Rotary kiln process is
widely utilized for zinc leaching residue treatment. The equipment and facilities of
rotary kiln process are easy to operate. However, zinc recovery is low when the low
zinc content slag is treated with rotary kiln process, because the effective contact area
between reductant and slag in rotary kiln is small, and the slag in rotary kiln is not
totally in molten. At the same time, a large amount of metallurgical coke is consumed
during the process, which will increase the operation cost [1]. Fuming furnace process
is a kind of molten bath smelting technology, and pulverized coal is utilized as
reductant. The pulverized coal and CO produced by pulverized coal combustion will
have reaction with metallic oxide in the molten bath. This technology can be utilized
to treat various raw materials and has high recovery of zinc and lead. Currently, this
technology has been widely utilized for the treatment of antimony smelting slag,
lead smelting slag, and zinc leaching residue. Based on research study on antimony
smelting slag and operation experiences, the fuming furnace process is utilized by
Guangxi Shengfu Antimony to treat such antimony smelting slag. The factory has
been in operation for two years. This paper introduces the actual production situation.
Finally, it is proved that Zn, Pb, and Sb are effectively recovered by fuming furnace
process after a period of operation. Therefore, the fuming furnace technology solves
the problem of antimony slag storage which containing Zn, Pb, and Sb and effectively
recovers the valuable resources as well.
Process Theory
Antimony smelting slag is produced from blast furnace during antimony oxides
reduction. The slag composition of such antimony smelting slag is FeO–SiO 2 –CaO,
and Pb, Zn, and Sb in slag appears as complicated oxides. In the antimony smelting
slag, part of Pb exists in the form of PbS. In the heating stage, PbS is oxidized into
oxide PbO, and a small part of PbO, ZnO, and Sb 2 O 3 volatilizes into dust. Most
lead, zinc, and antimony oxides in the slag will have reaction with pulverized coal
and CO produced from pulverized coal combustion to recover metals lead, zinc, and
antimony. The major chemical reaction in the molten bath is as follows [2] (Fig. 1):
C(s) + O 2 (g) = CO 2 (g)
2C(s) + O 2 (g) = 2CO(g)
ZnO(1) + CO(g) = Zn(1) + CO 2 (g)