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1

Effect of crushing type on the efficiency of flowing film separation

Sirkeci A. A., Gul A., Bulut G., Ozer M., Guven O., Perek K. T.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

601--608

EN

In recent years, the influence of different crushing systems (compression, impact, attrition) has been receiving more attention due to their significant role on particle liberation and shape of particles. The objective of this study was to investigate the effects of different crushing systems on both liberation degree and shape factors of chromite particles along with their enrichment conditions by shaking table. The tests were conducted on -1+0.5, -0.5+0.212 and -0.212 mm size fractions using the Wilfley type shaking table. The results of these tests showed that concentrates with higher metal contents were obtained by impact crushing of chromite in proportion to higher liberation degree and roundness of particles. Therefore, it was found that selective breakage can well be obtained by impact crushing in all fractions. The results of this study demonstrated the importance of crushing type on the liberation and enrichment processes.

2

The influence of pre-aeration on cyanide leaching of a non-refractory sulphide gold and silver ore

Aydin B., Basturkcu H., Gul A.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 2

647--660

EN

The leaching behaviour of a sulphide gold-silver ore was investigated in terms of a relationship between gold and silver extractions and cyanide consumption. Ninity five Au % and 88.0% Ag extractions were obtained under the determined conditions of 24 h leaching duration, -74 μm particle size, 40% solids ratio, 4 g/dm3 NaCN concentration, and 450 rpm stirring speed with NaCN consumption of 3.35 g/dm3. Since the NaCN consumption was higher than in industrial applications, Pb(NO3)2 and H2O2 additions and aeration using an air pump were tested during leaching in order to decrease the consumption. While Pb(NO3)2 addition with aeration caused a decrease in the metal extractions, the individual or combined additions of H2O2 and aeration could not provide a reduction in the cyanide consumption. Therefore, the effect of the pre-aeration followed by cyanidation was tested. Eventually, applying 4 h of pre-aeration before a shorter leaching duration of 12 h provided 92.0% Au and 90.5% Ag extractions with a reduced NaCN consumption of 2.44 g/dm3.

3

Improvement of mechanical strength of iron ore pellets using raw and activated bentonites as binders

Gul A., Sirkeci A. A., Boylu F., Guldan G., Burat F.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 1

23--36

EN

In this study, sodium, calcium, and mixed bentonite samples were used as binders in the pelletizing fine iron ore concentrate obtained from the Divrigi Iron Ore Concentration Plant in Turkey. In the pelletizing tests, sodium bentonite sample was used as received and after upgrading process. Additionally, the calcium bentonite sample required activation by sodium bicarbonate while the mixed bentonites sample was used untreated and as well as activated. The pellets produced were tested for compressive strengths, drop number, and porosity in order to characterize the pellets. The results showed that untreated and upgraded sodium bentonite samples provided relatively stronger pellets compared to calcium and the mixed type bentonite samples needed activation with sodium bicarbonate to increase the strength of the pellets. Based on the results of the drop number, compressive strengths, and porosity, it is possible to make pellets which meet the standards by adequate addition of type and amount of bentonite.

4

Beneficiation of arsenic bearing complex sulphide ore by flotation

Gul A., Bulut G., Sirkeci A. A.

Physicochemical Problems of Mineral Processing

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2013

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Vol. 49, iss. 1

203--212

EN

In this study beneficiation of a sulphide ore from the Gümüşhane-Black Sea Region of Turkey was investigated. Detailed flotation studies were carried out with the ore sample which contained 2.95% Pb, 6.72% Zn and 0.32% Cu. Mineralogical analyses showed that the sample includes pyrite, galena, sphalerite, chalcopyrite, tennantite, cerussite, anglesite and smithsonite. On the other hand, hematite, goethite, limonite, calcite and quartz were determined as gangue minerals. Selective sulphide concentrates with low arsenic content were tried to be produced by froth flotation. Individual concentrates of Pb, Zn and Cu assayed 67.54% Pb, and 61.49% Zn and 23.31% Cu where corresponding recoveries were 73.0% and 77.1% and 38.7%, respectively. Arsenic contents were less than 2000 ppm in the lead and zinc con-centrates. Copper concentrate assayed 5.03% As since the major copper minerals were in tennantite form (copper arsenic sulphide mineral). In flotation tests, non-toxic reagents such as metabisulphite, caustified starch, and activated carbon were used to depress minerals in relevant circuits.

5

Serum glycoproteins in diabetic and non-diabetic patients with and without cataract

Gul A., Rahman A. M., Ahmed N.

Optica Applicata

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2008

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Vol. 38, nr 3

531-538

EN

This study describes the changes in serum glycoproteins from type 2 diabetic and non-diabetic patients with and without cataract. A total of 85 subjects were selected for the study and divided into four groups. The first group consisted of 21 healthy subjects, the second group consisted of 21 diabetic patients with no chronic complications, the third group consisted of 20 diabetic patients with cataract, and the fourth group had 23 non-diabetic patients with age related cataract. The patients with and without cataract were selected on clinical grounds from the Ziauddin University and Jinnah Postgraduate Medical Centre in Karachi, Pakistan. As expected diabetic patients with and without cataract had significantly higher levels of fasting plasma glucose, glycated haemoglobin, glycated plasma proteins and serum fructosamine. In addition to these parameters, the levels of hexosamine, sialic acid and serum total protein were higher in diabetic compared to non-diabetic subjects with age related cataract and healthy subjects. Analysis of the protein fractions showed that alpha-1-globulins and alpha-2-globulins were higher in diabetic patients without complications compared to non-diabetic subjects with age related cataract and healthy subjects. Serum alpha-1-globulin, alpha-2-globulin, beta globulins and gamma globulins were all significantly higher in diabetic patients with cataract compared to healthy subjects but not serum albumin. In conclusion, the levels of beta globulins and gamma globulins were significantly higher in diabetic patients with cataract and non-diabetic age related patients with cataract compared to healthy subjects. Thus, mechanisms other than hyperglycaemia are responsible for the development of cataract in these patients.