Engıneer Mınnıng

Biochar, a carbon-rich solid product of slow pyrolysis of biomass, has gained interest due to its application in the various aims. Investigating of adsorption properties of biochar for removing pollutants from waste water is current research areas. The objective of this study is to obtain biochar from industrial tea waste, characterise it in detail and determine biochar's heavy metal adsorption potential to Ni(II) ions. Biochar prepared at 300°C and 400°C and characterised by various methods; elemental analysis, TGA, XRD, XRF, SEM and FTIR. The surface area and pH were determined as well. It was found out that biochar is mesoporous and the structures show more cellulosic characteristics. Carbonisation and aromaticity increase with increasing temperature. The magnitude of adsorption potential is between 500 J/mol and 4000 J/mol and decreases with increasing Ni concentration from 85 ppm to 205 ppm. The adsorption capacities of biochar are much lower than origin of biomass.

The natural sepiolite clay mineral was obtained from General Directorate of Mineral Research and Exploration (MTA) of Turkey and modified with 2.5 M of NaOH. The natural (SP) and modified (Na-SP) sepiolite samples were characterized by XRD, N2 adsorption-desorption, FTIR, SEM-EDS and NH3-TPD. The treatment of the sepiolite with NaOH led to a significant desilication and decationization of the SP. The alkali treatment with NaOH caused solution of silicon and cations, resulting in an increase in its average pore diameter and a decrease in its surface area from 187. 8 m g to 7.1 m g. In addition, a number of weak and medium acid centres of SP was decreased while a number of strong acid centres was increased. The maximum As(III) and As(V) removal with the SP was achieved at an initial pH of 1.5, respectively; ca. 8.9 mg g and 26.8 mg g. The maximum removal of As(III) and As(V) with Na-SP was achieved at an initial pH of 5.0; ca. 46.7 mg g and 35.9 mg g, respectively. The maximum Mn(II) ...

New iodide-, thiocyanate-and perchlorate-selective liquid membrane electrodes based on the tris (2,2′,2′′salicylidene-imino)triethylamine-iron (III) complex has been reported. These electrodes exhibit linear Nernstian responses over the range 1.0 ×10 −1 -1.0 × 10 −5 M for thiocyanate and perchlorate and 1.0 × 10 −1 -1.0 × 10 −4 M for iodine, with slopes of 51.8 ± 1.4 mV per p[SCN], 55.9 ± 1.0 mV per p[ClO 4 ] and 55.2 ± 3.6 mV per p [I]. The effects of the pH and the liquid membrane composition were also investigated. The proposed electrodes have a fast response time and nearly micro molar detection limits. The lifetimes of the electrodes are at least one month. The potentiometric selectivity coefficients for some monovalent ions were evaluated by the mixed interference method. Applications of iodide and thiocyanate electrodes to potentiometric titration of these ions with silver nitrate are made.

The aim of our research was to apply Box-Behnken experimental design and response surface methodology for modeling of some Turkish coals. As a base for this study, standard Bond grindability tests were initially done and Bond work indexes (W i ) values were calculated for three Turkish coals. The Box-Behnken experimental design was used to provide data for modeling and the variables of model were Bond work index, grinding time and ball diameter of mill. Coal grinding tests were performed changing these three variables for three size fractions of coals (À3350 + 1700 lm, À1700 + 710 lm and À710 lm).

In this study, a three-level Box-Behnken factorial design combined with response surface methodology (RSM) for modeling and optimizing of some operations parameter of Multi-Gravity Separator (MGS) to produce a celestite concentrate was developed. The three significant operational parameters of MGS, which are drum speed, tilt angle and shake amplitude, were varied and the results evaluated with the Box-Behnken factorial design. Second-order response functions were produced for the celestite grade and recovery of the concentrate. Taking advantage of the quadratic programming, a drum speed of 150 rpm, tilt angle of 6°and shake amplitude of 20 mm have been determined as optimum levels to achieve the maximum SrSO 4 concentrate grade of 96.91%, whereas the maximum level of grade was 95.69% in the tests conducted or predicted. In the same way, a drum speed of 250 rpm, tilt angle of 2°and shake amplitude of 10 mm has been determined as optimum levels to achieve the maximum recovery of 98.35%, whereas it was 95.83% in the tests conducted or predicted.

A three-level Box-Behnken factorial design combining with a response surface methodology (RSM) was employed for modeling and optimizing three operations parameters of the flotation on lead flotation. The flotation studies of lead ores containing 7.1% Pb were carried out in this study. The variables studied were potassium amyl xanthate (KAX) as a collector, sodium sulfide (Na 2 S) and pH. Experiments were carried out using Box-Behnken factorial design. The main and interaction effects were evaluated using response surface methodology. Second order response functions were produced for both the Pb grade and recovery. These response functions were then optimized using the quadratic programming method to maximize Pb grade and recovery within the experimental range studied. The optimum composition was found to be 212 g/t KAX, 1250 g/t sodium sulfide and 9 pH to achieve the maximum Pb grade. The model prediction of 47.44% Pb at optimum conditions was higher than any value obtained in the initial experiments conducted. In the same way, the optimum composition was found to be 100 g/t KAX, 1250 g/t Na 2 S and 7 pH to achieve the maximum recovery. The model prediction of 84.58% recovery at optimum conditions was also higher than any value obtained in the initial experiments conducted.