Gülay Bulut

RECOVERY OF Co, Ni, AND Cu FROM THE TAILINGS OF DIVRIGI IRON ORE CONCENTRATOR

In the Sivas-Divriği Iron Ore Concentrator, 600,000 t of tailings are discarded annually. There are already 1 million t of tailings deposited in ponds from the previous production activities. The presence of Co, Ni, and Cu in the tailings makes the beneficiation of those tailings attractive. In the experimental work, sulphide concentrates were produced from these two types of tailings by flotation. Under optimum flotation conditions, a bulk sulphide concentrate assaying 0.376% Co, 0.721% Ni, and 0.403% Cu was obtained with 83.1% Co, 57.7% Ni, and 59.0% Cu recoveries from the old tailings. On the other hand, another concentrate containing 0.384% Co, 0.687% Ni, and 0.393% Cu was produced under the same flotation conditions with 94.7% Co, 84.6% Ni, and 76.8% Cu recoveries from the new process tailings.

The Effect of Collector's Type on Gold and Silver Flotation in a Complex Ore

Gold and silver are recovered by gravity concentration, cyanidation, or flotation from ores. The choice of those processes depends on the mineralogical characterization as well as gold and silver contents of the ore. Flotation has been applied on ores containing free gold and silver particles for many years. The flotation efficiency of gold and silver particles depends on the modifiers and collectors. This paper presents the results of the effect of different collector combinations on gold and silver recoveries from lead and zinc ores by flotation. Best results were obtained on the use of Aero 208 + Aerophine 3418 A as collectors at the dosages of 350 + 350 g/t and 1000 g/t Na2SiO3 as a depressant at pH 4.5 where particle size was below 38 µm. According to the process, a concentrate assaying 1026.9 g/t Au and 10185 g/t Ag was obtained. On the other hand, a concentrate containing 50.6% Pb was obtained with 39.7% recovery using potassium amyl xanthate (KAX) and aminothiophenol (ATP). This concentrate graded 235 g/t Au and 3740 g/t Ag.

PROCESS FLOWSHEET DEVELOPMENT FOR BENEFICIATION OF NICKEL ORE

Nickel sulphide ore subjected to this investigation was taken from the Marmara district of Turkey, where widespread chromite mineralization can be observed. Some amounts of magnetite and chromite exist in the ore together with sulphide and oxide type nickel minerals. The ore sample contains 1.32% Ni, 10.79% SiO2, 78.39% Fe2O3, 1.3 g/t Ag, and 1.0 g/t Au. The ore sample is constituted of about 70% magnetite, 15% sulphide minerals, and 5% chromite and iron oxides, as well as 10% gangue minerals. Nickel mineralization in the ore such as pentlandite, violarite, millerite awaruite, and asbolanewas determined. Due to the complex structure of mineralization, a combination of gravity-separation and flotation methods was applied for the concentration of nickel sulphide and oxide ores. A nickel concentrate containing 12.32% Ni was produced with 89.7% recovery and final tailings with 0.088% Ni can be disposed with 4.9% of metal loss. A process flowsheet was developed according to the optimum test results. The importance of this research is that it is the first example of developing a flowsheet for the beneficiation of sulphide and oxide type nickel mineralization observed together in chromite ore deposits.

Characterization and production of Turkish nepheline syenites for industrial applications

Nepheline syenite, which is a silica-poor crystalline rock, competes with feldspar in applications such as glass, ceramic filler, and pigment industries. While its appearance is medium coarse granular like granite, main differences between them are nepheline syenite is silica poor, and contains high alumina and alkali content. Turkey has considerable nepheline syenite deposits in Kırşehir Region, and they contain 1.3% Fe2O3 on average, thus cannot be used unless beneficiated by flotation or/and magnetic separation. In this paper, physical and physicochemical experiments were carried out to improve the quality of nepheline syenite ore. After determinations of chemical, mineralogical, and properties of the sample, three different technologies such as flotation, magnetic separation, and leaching were applied on the ore sample, separately and combined. The obtained results showed that the magnetic separation alone could not produce a nepheline syenite concentrate assaying 0.45% Fe2O3. It was not also possible to obtain a nepheline concentrate less than 0.25% Fe2O3 adapting optimum flotation conditions. The best results were found in combination of the high intensity wet magnetic separation and flotation between -212+63 μm particle size, and a final concentrate with 0.20% Fe2O3 and 0.01% TiO2 was obtained. The leaching experiments were conducted to further decrease Fe2O3 content. Finally, a saleable nepheline syenite concentrate for tile, sanitary ware, electrode, glass, and fiberglass industries was obtained with 6.63% K2O, 9.02% Na2O, 0.15% Fe2O3, and 0.01% TiO2 by the weight of 63.9% at the end of the experiments.

LEACHING OF MASSIVE RICH COPPER ORE WITH ACIDIFIED FERRIC CHLORIDE

Massive rich copper ore, taken from the Küre region of Turkey and containing 7.95% Cu, 2.13% Pb, 0.341% Zn, 0.087% Co, 0.039% Ni, 0.9 (g/t) Au, and 17 (g/t) Ag, was subjected to the experimental study. Effects of leaching time, ferric ion concentration, solid/liquid ratio, acid concentration and temperature on the metal dissolution efficiencies were investigated in order to determine optimum leaching conditions and related leaching kinetics. As a result of these experiments carried out under the optimum leaching conditions, 76% of Cu, 55% of Co, 96% of Ni, 100% of Pb, and 91% of Zn were extracted. The value of apparent activation energy for copper dissolution was found as 43.8 kJ/mole, which is in agreement with the published data. The rate-controlling step was found as the diffusion of ferric ions into the sulfur layer formed on the surface of partially leached ore particles.