Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Concentration of chromite by means of magnetic carrier using sodium oleate and other reagents

Ucbas Y., Bozkurt V., Bilir K., Ipek H.

Physicochemical Problems of Mineral Processing

2014

Vol. 50, iss. 2

767--782

Chromite recovery was studied using a magnetic carrier technology. Heavy media grade magnetite was used as the magnetic carrier. The effect of various reagents such as sodium oleate (NaOl) as a collector and carboxymethyl cellulose (CMC) as well as quebracho tannin as depressants on chromite removal was investigated. The effects of pH and reagent dosages were also determined. First, the zeta potential measurements were performed for different minerals in the absence and presence of NaOl, and then magnetic carrier tests were carried out under conditions based on zeta potential measurements. The magnetic carrier tests performed in the case of individual minerals (i.e. single minerals) showed that chromite (recovery of 95.1%) could be separated from serpentine (recovery of 3.2%) whereas it could not be separated from olivine. The best chromite concentrates containing 42.1% Cr2O3 were obtained with a 76% recovery from a synthetic mixtures of chromite and serpentine under optimum test conditions, that is at pH 10.5, 5.10–5 M NaOl, 20 g/Mg CMC, 0.5 g magnetite and 500 g/Mg kerosene (the feed contained 27% Cr2O3). Slime tailings of Turkish Maadin Company, Kavak Chrome Concentrating Plant in Eskisehir, which contain fine chromite, serpentine and olivine, were also investigated. It was found that chromite could not be satisfactorily recovered from the original slime sample in the presence and absence of NaOl by using the magnetic carrier technology. Additional FTIR studies performed with the investigated minerals showed that NaOl adsorption on chromite was greater than that on serpentine and magnetite minerals. It was also found that NaOl adsorption on serpentine is significantly reduced in the presence of magnetite while it increases only slightly on chromite.

The evaluation of grinding process using MODSIM/C

Umucu Y., Deniz V., Bozkurt V.

AGH Journal of Mining and Geoengineering

2012

Vol. 36, no. 4

187-200

There are programs for the computer design of mineral processing circuits, and that these programs contain computer simulation models for ball mill design. Simulation techniques are popular because they allow complex problems to be tackled without the expenditure of large resources. MODSIMŠ is a simulator that will calculate the detailed mass balance for any ore dressing plant. MODSIMŠ can simulate integrated flow sheets that include grinding. In this studies S/i and B/ij (selection and breakage distribution functions) equations were determined from the size distributions at different grinding times and with model parameters (S/i, a/t, alpha, gamma, Beta and phi/J) for different powder filling ratios. Experimentally determined data were statistically compared with data obtained from MODSIMŠ simulator program using model parameters.

Istnieją programy do komputerowego projektowania systemów przeróbki surowców mineralnych zawierające również modele symulacyjne służące do projektowania młynów kulowych. Popularne są techniki symulacyjne ponieważ umożliwiają one rozwiązywanie skomplikowanych problemów bez dużej bazy danych. Jednym z takich symulatorów jest program MODSIMŠ, który oblicza szczegółowy bilans masowy dla jakiegokolwiek zakładu wzbogacania. MODSIMŠ może symulować zintegrowane systemy przeróbcze, zawierające w sobie podsystemy rozdrabniania. W artykule przedstawiono równania dla S/i oraz B/ij (funkcje rozkładu selekcji i rozdrabniania) określone dla składów ziarnowych otrzymanych po różnych czasach rozdrabniania i przy zastosowaniu parametrów modelu (S/i, a/t, alfa, gamma, Beta and phi/J) dla różnych stosunków wypełnienia materiałem komory młyna. Dane eksperymentalne zostały statystycznie porównane z danymi otrzymanymi z programu MODSIMŠ przy zastosowaniu parametrów modelu.

Workplace Violence: A Study of Turkish Workers

Aytac S., Bozkurt V., Bayram N., Yildiz S., Aytac M., Akinci F. S., Bilgel N.

International Journal of Occupational Safety and Ergonomics

2011

Vol. 17, No. 4

385--402

This research was conducted to address the experience of workplace violence of Turkish workers from different sectors and to investigate the impact of the exposed violence on their psychological well-being. Data were collected anonymously with printed questionnaires from the volunteer participants and depended on self-reporting. The response rate was 79.0% (1708/2161). The prevalence of workplace violence was found to be 44.8%. The most common type was verbal violence together with mobbing (bullying). Victims of physical violence were mostly males, whereas females were found to be victims of verbal, psychological and sexual violence. Most cases did not result in legal action and the victims remained silent. Psychological well-being of exposed workers in terms of depression, anxiety and stress seemed to deteriorate. Workplace violence remains a silent epidemic in Turkey. Preventive measures against workplace violence and social support for violated workers do not exist.