452
M. Kaya et al.
Tailing samples were roll crushed, dried, sieved (−3.175 mm), ball milled 5 min for
deagglomeration and dispersion, and then homogenized by mixing. Sample contains
5.3% moisture and has specific density of 3.46 g/cm
3 and surface area of 3456 g/cm
3
[5]. The particle size distribution of the tailing material was determined by Malvern
Inst. Mastersizer 2000. d 10 of Oreks tailing sample was around 1 μm, d 50 13 μm, d 80
57 μm, and d 90 100 μm. As can be seen from the results, almost half of the sample is
less than 10 μm in size. Major oxides in the flotation tailing sample were determined
using Panalytical Zetium WDXRF. Mineralogical composition and phases of flotation tailing sample were examined using XRD. The major mineral peaks were from
smithsonite (ZnCO 3 ) (4%), cerrussite (PbSO 4 ) (0.8%), goethite (FeO(OH)) (2.4%),
calcite (CaCO 3 ) (32.2%), quartz (SiO 2 ) (13.8%), corkite [PbFe 3 [(OH) 6 :SO 4 :PO 4 ]
(7.8%), and beudantite (PbFe 3 (OH) 6 SO 4 AsO 4 ). Flotation tails also contain hemimorphite (Zn 2 SiO 4 ·H 2 O), quartz, dolomite, zinc sulphite hydrate (ZnSO 4 ·7H 2 O),
gypsium, and melanterite (FeSO 4 ·7H 2 O) as minor phases. In this tailing, smithsonite
and cerrussite (i.e. Zn and Pb) are the important and abundant base metals. Major
gangue minerals can be goethite, quartz, calcite, and kaolinite. ICP-AES analysis
of tailing sample contained 7.50% Pb; 5.77% Zn; 21.3% Fe; 3.91% Ca; 1.92% Al;
1.85% S; 0.66% K; 0.45% Mg; 0.10% Ti; 101 ppm Ag; 101 ppm As > 10,000 ppm
Ba; 376 ppm St; 306 ppm Cu; 279 ppm Sb; 245 ppm Cd; 63 ppm Cr; 43 ppm V;
20 ppm Tl, U, and W; <20 ppm Th; 10 ppm Ga, La, and Ni; 9 ppm Mo; <2 ppm Bi;
<1 ppm Co, and 0.6 ppm Be. Major metals in flotation tail sample are Pb, Zn, Fe,
and As [5]. The particle morphology and surface composition of flotation tails were
detected by SEM-EDX analyses. Surface morphology of particles is very rough,
porous, and complex. Different shapes and sizes are observed [5].
Method
The sample was not exposed to any metallurgical pre-treatment operations before
leaching. Analytical grade Merck/Sigma acids were used in this study. Deionized
water was used throughout experimental tests. All leaching experiments were conducted at atmospheric pressure. The leaching experiments were conducted in a magnetically stirred three-necked Pyrex reactor (0.5 dm
3 ) equipped with a glass reflux
condenser inside a temperature controlled extraction mantle (MTops) (Fig. 1).
For each laboratory scale batch leach test, 25 g of solid tailing samples are used
with S/L ratio of 1/10 (w/v). Constant 400 rpm stirring speed was used. Particle
size was also constant for all tests. In this study sample, the withdrawal method is
mainly used. At certain time intervals, 5–10 mL of samples are withdrawn from
leach medium and analyzed for dissolved metals while leaching continues until final
leaching period. This method is faster and requires less time, samples, and reagents.
Samples were immediately vacuum filtered, centrifuged at 5000 rpm, diluted, and
stored at 4 °C before Zn, Pb, and Fe (three elements) analyses with AAS at ESOGU
and/or Zn, Pb, Fe, As, and Ag (five elements) analyses with ICP at ALS ( ˙ Izmir).
During sample withdrawal, pH of the solution and at the end of leaching test PLS
M. Kaya et al.
Tailing samples were roll crushed, dried, sieved (−3.175 mm), ball milled 5 min for
deagglomeration and dispersion, and then homogenized by mixing. Sample contains
5.3% moisture and has specific density of 3.46 g/cm
3 and surface area of 3456 g/cm
3
[5]. The particle size distribution of the tailing material was determined by Malvern
Inst. Mastersizer 2000. d 10 of Oreks tailing sample was around 1 μm, d 50 13 μm, d 80
57 μm, and d 90 100 μm. As can be seen from the results, almost half of the sample is
less than 10 μm in size. Major oxides in the flotation tailing sample were determined
using Panalytical Zetium WDXRF. Mineralogical composition and phases of flotation tailing sample were examined using XRD. The major mineral peaks were from
smithsonite (ZnCO 3 ) (4%), cerrussite (PbSO 4 ) (0.8%), goethite (FeO(OH)) (2.4%),
calcite (CaCO 3 ) (32.2%), quartz (SiO 2 ) (13.8%), corkite [PbFe 3 [(OH) 6 :SO 4 :PO 4 ]
(7.8%), and beudantite (PbFe 3 (OH) 6 SO 4 AsO 4 ). Flotation tails also contain hemimorphite (Zn 2 SiO 4 ·H 2 O), quartz, dolomite, zinc sulphite hydrate (ZnSO 4 ·7H 2 O),
gypsium, and melanterite (FeSO 4 ·7H 2 O) as minor phases. In this tailing, smithsonite
and cerrussite (i.e. Zn and Pb) are the important and abundant base metals. Major
gangue minerals can be goethite, quartz, calcite, and kaolinite. ICP-AES analysis
of tailing sample contained 7.50% Pb; 5.77% Zn; 21.3% Fe; 3.91% Ca; 1.92% Al;
1.85% S; 0.66% K; 0.45% Mg; 0.10% Ti; 101 ppm Ag; 101 ppm As > 10,000 ppm
Ba; 376 ppm St; 306 ppm Cu; 279 ppm Sb; 245 ppm Cd; 63 ppm Cr; 43 ppm V;
20 ppm Tl, U, and W; <20 ppm Th; 10 ppm Ga, La, and Ni; 9 ppm Mo; <2 ppm Bi;
<1 ppm Co, and 0.6 ppm Be. Major metals in flotation tail sample are Pb, Zn, Fe,
and As [5]. The particle morphology and surface composition of flotation tails were
detected by SEM-EDX analyses. Surface morphology of particles is very rough,
porous, and complex. Different shapes and sizes are observed [5].
Method
The sample was not exposed to any metallurgical pre-treatment operations before
leaching. Analytical grade Merck/Sigma acids were used in this study. Deionized
water was used throughout experimental tests. All leaching experiments were conducted at atmospheric pressure. The leaching experiments were conducted in a magnetically stirred three-necked Pyrex reactor (0.5 dm
3 ) equipped with a glass reflux
condenser inside a temperature controlled extraction mantle (MTops) (Fig. 1).
For each laboratory scale batch leach test, 25 g of solid tailing samples are used
with S/L ratio of 1/10 (w/v). Constant 400 rpm stirring speed was used. Particle
size was also constant for all tests. In this study sample, the withdrawal method is
mainly used. At certain time intervals, 5–10 mL of samples are withdrawn from
leach medium and analyzed for dissolved metals while leaching continues until final
leaching period. This method is faster and requires less time, samples, and reagents.
Samples were immediately vacuum filtered, centrifuged at 5000 rpm, diluted, and
stored at 4 °C before Zn, Pb, and Fe (three elements) analyses with AAS at ESOGU
and/or Zn, Pb, Fe, As, and Ag (five elements) analyses with ICP at ALS ( ˙ Izmir).
During sample withdrawal, pH of the solution and at the end of leaching test PLS