Influence of shape characteristics of talc mineral on the column flotation behavior

Column flotation, which is a very effective process in mineral processing especially for easily floatable minerals, is one of the most important new developments to emerge in mineral processing technology in the last years. In this study, the flotation behavior of talc products having different particle shapes produced by different grinding mills (ball and rod mill) was determined by using column flotation process. Shape characteristics of the particles were investigated by the two dimensional measuring technique based on the particle projections obtained from the SEM microphotographs using a COREL Draw 10.0 program. The results showed that particles possessing higher elongation and flatness properties were recovered better during column flotation, whilst roundness and relative width had a negative effect on the flotation behavior of the talc mineral studied. Consequently, as the shape of the particles produced by the mill deviated from the ideal sphere, their floatability was increased.     

Assessment of geo-environmental properties depressing urban development with GIS: a case study of Kozlu settlement,Turkey

Kozlu is a mining town only 5 km away from the main city of Zonguldak and initially was not favored for settlement due to its rugged and hilly topography. However, along with hard coal production in large quantities throughout the years came the industrialization at its full speed with plenty job opportunities which then gave rise to intense population in the region where there were only a few sheds and slums just a century ago. Workers migrating to Kozlu in thousands needed dwellings to live in, but the law, so-called the Coal Basin Restrictions Law which came in effect in 1910, hindered the implementation of zoning plans. Planned housing was not possible in the region not until the abolishment of the law in 1986. During these 76 years, the settlement in the area mostly by the mining and industry workers was carried out without proper zoning plans, usually on demand basis. Today because of this unplanned housing and harsh topography, the Kozlu settlement area (KSA) has a history of being attraction point for many natural and man-made disasters which can be summarized as are topography, geological and carstic structure, mining activities and mass movements. In this study, a settlement suitability map is produced for the study area using a geographic information system. The map produced is designated into four settlement suitability zones, namely suitable to settlement, slightly suitable to settlement, suitable to settlement with precautions and unsuitable to settlement. It clearly shows that 24.73% of the study area lies in suitable and slightly suitable to settlement areas while the bulky rest pertains to suitable to settlement with precautions and unsuitable to settlement. The latest studies show that the 37.5% of the buildings and houses in the KSA are situated on the lithologic units identified as hydrogeological permeable and semipermeable, 7.8% on carstic caverns and a hefty rate of 47.6% on the surfaces deformed by mining-induced subsidence. Therefore, it is needless to claim that the administrators of Kozlu should promptly develop a settlement plan for the welfare of the city.     

Elemental abundance analyses with DAO spectrograms – XXIII. The superficially normal stars 28 And (A7 III) and 99 Her (F7 V)

Elemental abundances of 28 And (A7 III) and 99 Her (F7 V), which have modest rotational velocities, are derived in a manner consistent with previous studies in this series of papers. The values for 28 And, a δ Scuti variable, show that it is slightly metal-poor, but not a classical Am star. 99 Her, which is somewhat more metal-poor, has a rather small microturbulence for its spectral type.     

Dynamic Responses of Block Type Quay Walls Under Cyclic Loading

The purpose of this research is to study the dynamic responses of gravity quay walls with block type consisting of“three blocks”experimentally.For this purpose,1g shaking table tests were conducted under different cyclic loadings for two different saturated granular backfill materials(Soil 1 and Soil 2).In this study,D_n50 of Soil 1 and Soil 2 are selected as 2.2 cm and 1.0 cm,respectively.During the experiments,accelerations,soil pressures and displacements were measured for each block.Test results pointed out that Soil 2 caused more damage on structures.The measurements for displacement and tilting of each block were discussed in view of“acceptable level of damage in performance-based design”given in PIANC(2001).The result of the study showed that the definitions of damaged levels given in PIANC(2001)were reliable for using in performance-based methods for seismic design of block type quay walls.     

An elemental abundance analysis of the magnetic chemically peculiar star HR 8216

An elemental abundance analysis of the cool magnetic CP star HR 8216 (= HD204411) was performed using 2.4 Å mm⁻¹ Dominion Astrophysical Observatory Reticon exposures covering  λλ3830–4770  with a typical signal-to-noise ratio of 200 taken with the long camera of the 1.22-m telescope. The spectrograms were measured interactively with the graphics computer program reduce . The fine analysis used an ATLAS9 metal-rich model atmosphere, the predictions of which best-matched the optical region fluxes and the Hγ profile. The anomalies of HR 8216 are primarily an enhancement of many iron peak elements with the rare earths elements much less enhanced than in many similar cool magnetic CP stars. Using the results of the fine analysis the spectrum was synthesized. Comparison with the observed spectrum showed that the agreement is good but did not fully account for all of the observed line spectrum.     

A survey to determine levels of chlorinated pesticides and PCBs in mussels and seawater from the Mid-Black Sea Coast of Turkey

A mussel and seawater monitoring survey was conducted at six sampling points between Yalikoy (Ordu) and Sinop in 1999-2000 along the Mid-Black Sea Coast of Turkey in order to assess concentrations of organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs). Chlorinated pesticides and PCBs were measured in the mussel Mytilus Galloprovincialis and in seawater. In the mussel samples, the most common pollutants in terms of average concentration per g of wet weight (ww), were DDT (max. 1800 pg/gww, min. 240 pg/gww) and its metabolites DDD (max. 5400 pg/gww, min. 240 pg/gww) and DDE (max. 2800 pg/gww, min. 70 pg/gww). Also, dieldrin, heptachlor and HCB were notable contaminants in the mussel samples. PCBs were determined in none of the biota or seawater samples. The concentrations of the OCs and PCBs in mussels were higher in coastal areas receiving river discharges and close to the largest city of the region, Samsun (especially in sampling points in the harbour area). The well-known long persistence of DDTs and other chlorinated compounds was confirmed by residues of these pollutants measured in mussels. On the other hand, even though the usage of such kind of persistent compounds in Turkey was banned, there may still be illegal usage and it is not certain whether the application of these compounds did end in the region.     

Evaluation of digital image processing (DIP) in analysis of magnetic separation fractions from Na-feldspar ore

Combination of flotation and magnetic separation methods is widely used for enrichment of feldspar ores by purifying from dark-colored gangue minerals such as iron and titanium. In this study, the removal of dark-colored minerals from feldspar ore (Aydin Cine region of Turkey) was studied using a dry magnetic separator. The effect of several parameters such as feed particle size, blade angle, and roll speed on the removal efficiency was investigated in detail. In addition, the gangue contents of the magnetic and non-magnetic products were determined by a digital image processing (DIP) method in terms of using color differences between the feldspar sample and gangue minerals. The results obtained from this study clearly indicated that the dry magnetic separation method can be successfully applied in enrichment of feldspar. Meanwhile, the particle size of the sample showed no significant influence on the separation recovery. According to the results obtained from the digital image processing process, the sample with 0.04% cross sectional area of dark-colored minerals can be obtained at roll speed of 100 rpm and 130° of blade angle using the original particle size of 500×106 μm. Additionally, most importantly, these results showed that digital image processing method can be used to determine gangue content (dark-colored minerals) of the magnetic separation products compared to conventional methods as a simple, a reliable, and a repeatable method.