Nurcan Tugrul

Effect of Magnesium Borates on the Fire-Retarding Properties of Zinc Borates

Magnesium borate (MB) is a technical ceramic exhibiting high heat resistance, corrosion resistance, great mechanical strength, great insulation properties, lightweightness, high strength, and a high coefficient of elasticity. Zinc borate (ZB) can be used as a multifunctional synergistic additive in addition to flame retardant additives in polymers. In this study, the raw materials of zinc oxide (ZnO), magnesium oxide (MgO), and boric acid (H3BO3) were used in the mole ratio of 1 : 1 : 9, which was obtained from preexperiments. Using the starting materials, hydrothermal synthesis was applied, and characterisation of the products was performed using X-Ray diffraction (XRD) and Fourier transform infrared (FT-IR) and Raman spectroscopies. The forms of Zn3B6O12·3.5H2O, MgO(B2O3)3·7(H2O), and Mg2(B6O7(OH)6)2·9(H2O) were synthesised successfully. Moreover, the surface morphology was investigated using scanning electron microscopy (SEM), and the B2O3 content was determined. In addition, the reaction yields were calculated. The results of the B2O3 content analysis were in compliance with the literature values. Examination of the SEM images indicated that the obtained nanoscale minerals had a reaction efficiency ranging between 63–74% for MB and 87–98% for ZB. Finally, the fire-retarding properties of the synthesised pure MBs, pure ZBs, and mixtures of MB and ZB were determined using differential thermal analysis and thermal gravimetry (DTA-TG) and differential scanning calorimetry (DSC).

A study on the structural behavior of reduced pyrite ash pellets by XRD and XRF analysis.

In Turkey, pyrite ash is created as waste from the roasting of pyrite ores in the production of sulfuric acid. These processes generate great amounts of pyrite ash waste that creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be used in the iron production industry as a raw material because of its high Fe2O3 concentration. The aim of this study was to investigate the reduction behaviour of pyrite ash pellets. The pyrite ashes were reduced to obtain the iron contained in pellets. Pyrite ashes samples were pelletized dried at 105 °C for 24 h and sintered at 1200 °C for 30 min. then reduced in a pressure of 4 atm. under argon gas. The mineralogical transformations that occurred during reduction were analysed by X-ray diffraction and X-ray fluorescence. The X-ray diffraction and X-ray fluorescence measurements of these samples showed that Fe3O 4 was successfully reduced to a metallic iron phase in a laboratory-scale electric arc furnace.

Effects of calcium hydroxide and calcium chloride addition to bentonite in iron ore pelletization

Pyrite ash is created as waste from the roasting of pyrite ores during the production of sulphuric acid. These processes generate great amounts of pyrite ash waste that is generally land filled. This creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be utilized in the iron production industry as a blast furnace feed to process this waste and prevent environmental pollution. The essential parameters affecting the pelletization process of pyrite ash were studied using bentonite as a binder. Experiments were then carried out using bentonite and a mixture of bentonite with calcium hydroxide and calcium chloride in order to make the bentonite more effective. The metallurgical properties of pyrite ash, bentonite, calcium hydroxide, calcium chloride, a mixture of these and sintered pellets were studied using X-ray analysis. The crushing strength tests were carried out to investigate the strength of pyrite ash waste pellets. The results of these analyses showed that pyrite ash can be agglomerated to pellets and used in the iron production industry as a blast furnace feed. The crushing strength of the pellets containing calcium hydroxide and calcium chloride in addition to bentonite was better than the strength of pellets prepared using only bentonite binder.

Synthesis of hydrophobic nanostructured zinc borate from zinc carbonate, and characterization of the product

In general, zinc oxide and boric acid are used to produce zinc borate. In this study, zinc carbonate was used instead of zinc oxide as the novel zinc source. The purpose of this study was to synthesize hydrophobic, nanostructured zinc borate (3ZnO·3B2O3·3.5H2O) by reaction of zinc carbonate, instead of zinc oxide, with boric acid reference material, and with zinc borate reference material as seed. The modifying agents propylene glycol, kerosene, and oleic acid were used to produce hydrophobic zinc borate. Different solvents (isopropyl alcohol, ethanol, and methanol) were used to obtain a homogeneous phase. The effects of different modifying agents and solvents on the hydrophobicity and nanostructure of the product were investigated. The synthesized zinc borate was characterized by X-ray diffraction and Fourier-transform infrared spectroscopy. Contact angles were measured to determine the hydrophobicity of the products and scanning electron microscopy was used to study both the morphology and nanostructure of the products. Hydrophobic, nanostructured zinc borate was successfully produced by use of zinc carbonate instead of zinc oxide as the novel zinc source. Use of different modifying agents and solvents affected both hydrophobicity and nanostructure.

X-Ray, Thermal, FT- IR and morphological studies of zinc borate in presence of boric acid synthesized by ulexite

Zinc borate (ZB) is an industrially important flame retardant material and ulexide is a plenty mineral in Turkey. ZB has been prepared via an aqueous reaction method using zinc oxide, synthesized boric acid by ulexide and reference zinc borate as seed as initial materials. This route is facile and acceptable for an economic and a new way to produce zinc borate. The products have been characterized by X-ray diffraction (XRD), Thermogravimetric/Differential Thermal Analysis (TG/DTA) and Fourier Transform Infrared Spectroscopy (FT-IR). Scanning electron microscope (SEM) was used to determine the morphological structure. The effects of experimental conditions on the product yield were investigated. Namely, the main factors that affect the formation of zinc borate were H 3 BO 3 /ZnO (boric acid/zinc oxide) ratio, water volume, amount of seed (in terms of boric acid, w/w) and reaction time. In conclusion, it was observed that boric acid by using ulexide mineral and zinc borate were synthesized successfully.

Production and characterization of hydrophobic zinc borate by using palm oil

Zinc borate (ZB) was synthesized using zinc oxide, boric acid synthesized from colemanite, and reference ZB as seed. The effects of reaction parameters such as reaction time, reactant ratio, and seed ratio on its yield were examined. Then, the effects of palm oil with solvents (isopropyl alcohol (IPA), ethanol, and methanol) added to the reaction on its hydrophobicity were explored. Reactions were carried out under determined reaction conditions with magnetically and mechanically stirred systems. The produced ZB was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and measurements of contact angle identified hydrophobicity. The results showed that hydrophobic ZB was successfully produced under determined reaction conditions. The change of process parameters influenced its yield and the usage of palm oil provided hydrophobicity.

Characterization and physical properties of hydrated zinc borates synthesized from sodium borates

Abstract In this study, Zn3B6O12·3.5H2O, a type of a zinc borate hydrate, was synthesized from the sodium borate mineral Na2B4O7·5H2O. Two different zinc sources, i.e. ZnSO4·7H2O and ZnCl2, were used in the hydrothermal synthesis. Products were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. Product morphologies were studied using scanning electron microscopy (SEM). Then optical absorption characteristics and electrical properties were investigated. Based on these results, Zn3B6O12·3.5H2O was obtained under many synthetic conditions as a single phase with high reaction efficiencies and sub-micrometer (100 nm to 1 μm) particle sizes. The electrical resistivity and optical energy gap were found as 8.8×1010 Ω cm and 4.13 eV, respectively. The novelty obtained in this study is the synthesis of zinc borate hydrate compound with high crystallinity without using any modification agent or organic solvent.

Effect of modifying agents on the hydrophobicity and yield of zinc borate synthesized by zinc oxide

The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time (1–5 h), reactant ratio (H3BO3/ZnO by mass: 2–5), seed ratio (seed crystal/(H3BO3+ZnO) by mass: 0–2wt%), reaction temperature (50–120°C), cooling temperature (10–80°C), and stirring rate (400–700 r/min); the modifying agents involve propylene glycol (PG, 0–6wt%), kerosene (1wt%–6wt%), and oleic acid (OA, 1wt%–6wt%) with solvents (isopropyl alcohol (IPA), ethanol, and methanol). The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.