41 research outputs found
An experimental study on the linear differential scattering coefficients of the Trommel Sieve Waste (TSW)
The linear differential scattering coefficients (LDSCs) at 60 keV are measured for TSW at seven angles ranging from 60 degrees to 120 degrees at intervals of 10 degrees. The results are compared with relativistic and non-relativistic theoretical values. The purpose of this work is to seek evidence whether there is a relationship between the LDSC and the scattering angle. This is the first time the LDSCs have been measured at energies lower than 100 keV, so there is a lack of comparable findings reported in the literature. (C) 2009 Elsevier Ltd. All rights reserved
KINETICS OF DESULFURIZATION OF NEVSEHIR-DADAGI COAL WITH FERRIC-CHLORIDE SOLUTIONS
The desulphurization of Nevsehir-Dadagi lignite with acidic ferric chloride solution and its kinetics and mechanism were investigated. It was found that the effects of the leaching temperature and particle size on the removal of pyritic sulphur are very significant. For larger particles (+ 250 and + 355 mum), the amount of pyritic sulphur removed was 20 wt%. For particles smaller than 250 mum a pyritic sulphur removal of 40-65 wt% was obtained. The removal of pyritic sulphur increased with increase in temperature. The increase of the FeCl3 concentration and the decrease of the acidity also increased the removal of pyritic sulphur. The desulphurization process was found to be well described by the unreacted core model of unchanging size. The overall controlling step was found to be diffusion from the ash layer. A rate equation including the reaction parameters for the decomposition of pyritic sulphur was also established. The activation energy and Arrhenius constant of the reaction were found to be 30.6 kJ mol-1 and 117.5 s-1, respectively
Experimental studies on measurements of mass attenuation coefficients of boric acid at different concentration
Measurements have been made to determine variation of the mass attenuation coefficients of H3BO3 according to percentage increasing concentration of H3BO3 by using an extremely narrow-collimated-beam transmission method in the energy range 15.746-40.930 keV with an X-ray transmission method. The characteristic K-alpha and K-beta X-rays of the different elements (Zr, Mo, Ag, In, Sb, Ba and Pr) passed through boric acid was detected with a high-resolution Si(Li) detector. Results are presented and discussed in this paper. (C) 2003 Elsevier Ltd. All rights reserved
Borax production from borax slime, an industrial waste
Borax slime is formed during the production of borax from tincal, which is an important berate ore. It is a liquid containing the suspanded solid particles at high levels and is formed under the rich-in-borax solution in the reactor. This waste is discharged into the Marmara Sea and so causes environmental problems in Bandirma Golf. In this work, Borax production is aimed from the slime containing B2O3 at important levels. As a result it was found that B2O3 can be recovered and therefore the B2O3 pollution can be prevented by removing it from the waste
ELEMENTAL SULFUR FORMATION IN THE MEYERS COAL DESULFURIZATION PROCESS
The rate of formation of elemental sulfur on the surface of lignite particles during leaching by acidic ferric chloride was found to depend on the concentration and acidity of the ferric chloride, the particle size of the sample, the temperature and the rate of stirring. Generally, S formation increased during the first 40-45 min of leaching and subsequently decreases. It was more significant with small particles and high acidities
Desulphurization of two Turkish lignites in an entrained flow reactor
Desulphurization of Balkaya and Bolu-Mengen lignites by flash pyrolysis in an entrained flow reactor under nitrogen atmosphere was investigated. Experiments were conducted in a 450-750 degrees C temperature range. The change of sulphur types, the removal of total sulphur and volatile matter with pyrolysis temperature were found. The removal of the total sulphur and the volatile matter for Balkaya lignite at 750 degrees C were obtained as 42.2 and 72.7%, respectively, while these values are 57.0 and 66.8% for Bolu-Mengen lignite at the same temperature. (C) 1997 Elsevier Science B.V
Measurement of mass attenuation coefficients of some boron compounds and the trommel sieve waste in the energy range 15.746-40.930 keV
Mass attenuation coefficients of some boron compounds (H3BO3, Na2B4O7 and B3Al2O3) and the trommel sieve waste (TSW) have been measured by using an extremely narrow collimated-beam transmission method in the energy range 15.746-40.930 keV. The characteristic Kalpha and Kbeta X-rays of Zr, Mo, Ag, In, Sb, Ba and Pr passed through H3BO3, Na2B4O7, B3Al2O3 and TSW were detected with a high-resolution Si(Li) detector. The measured values are compared with the theoretical ones obtained using the WINXCOM. (C) 2003 Elsevier Science Ltd. All rights reserved
Determination of molecular, atomic, electronic cross-sections and effective atomic number of some boron compounds and TSW
The transmission of gamma-rays of some boron compounds (H3BO3, Na2B4O7) and the trommel sieve waste (TSW) have been measured by using an extremely narrow-collimated-beam transmission method in the energy range 15.74-40.93 keV. Molecular, atomic and electronic cross-sections and effective atomic numbers have been determinated on the basis of mixture rule and compared with the results obtained from theory. (C) 2008 Elsevier B.V. All rights reserved
Upgrading of the reactor waste obtained during borax production from tincal
Boron ores are used in the production of various boron compounds. One of the most important of them is borax obtained from tincal During borax production a large quantity of the boron oxide (B2O3) is lost with the reactor waste, Also, this waste causes different environmental problems when it discharged directly to the environment, In this study, the evaluation of the reactor waste in borax production was investigated to recover B2O3 and therefore to reduce the toxic effect of the waste. For this purpose, the reactor waste was leached by SO2-saturated water. It was found that about 90 % of B2O3 in the waste was recovered. In addition, about 80 % of CaO in the waste was dissolved in the leaching solution. A part of the dissolved CaO precipitated as CaSO3.1/2H(2)O and CaSO4.2H(2)O, and the other part remained as Ca(HSO3)(2) in the solution, It is possible that CaSO3. 1/2H(2)O and Ca(HSO3)(2) can be used in the paper industry and in other some industries. (C) 1999 Elsevier Science Ltd. All rights reserved
Electro-oxidation of pistachio processing wastewater using Ti/Pt mesh-type anodes in batch system
In this study, the treatment of pistachio processing wastewater (PPW) by electro-oxidation method was investigated. Ti/Pt-plated electrodes were used for the anode material, and stainless steel electrodes were used for cathode material. Experimental studies were carried out in batch mode. Stirring speed, supporting electrolyte species and concentration, initial pH value, current density, temperature and dilution ratio were selected as experimental parameters effecting removal efficiency. In Ti/Pt electrode experimental studies on the optimum conditions, chemical oxygen demand (COD), total organic carbon (TOC) and total phenols (TP) removal efficiencies were obtained, respectively, as 99.98%, 70.74% and 100%, and energy consumption value was obtained as 297.5 kW-h/m(3) (12.39 kW-h/kg COD, 51.29 kW-h/kg TOC and 64.68 kW-h/kg TP). As a result of the experimental studies, the PPW can be treated by electro-oxidation. Given the results of removal efficiency and energy consumption values, it was concluded the electro-oxidation using Ti/Pt anode very appropriate treatment of PPW