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In this study, zinc borate hydrate (Zn 3 B 6 O 12 · 3.5H 2 O) was synthesized from zinc oxide (ZnO) and boric acid (H 3 BO 3 ) via a novel method of ultrasonic irradiation. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy were used to characterize the synthesized products. Scanning electron microscopy (SEM) was used to determine the effects of reaction time and reaction temperature on the morphology of the products. Thermal dehydration kinetics were studied using thermal gravimetry and differential thermal gravimetry analysis (TG/DTA). The Doyle and Kissinger non-isothermal kinetic methods were used to analyse the TG/DTA data. The XRD results confirmed the successful synthesis of Zn 3 B 6 O 12 · 3.5H 2 O at a range of reaction temperatures and times. Additionally, FT-IR and Raman analysis of the products identified peaks specific to zinc borate. Using the methods of Doyle and Kissinger, the activation energies of thermal dehydration of zinc borate were found to be 341.61 kJ/mol and 390.17 kJ/mol, respectively.

In this study, Zn

Magnesium borates are significant compounds due to their advanced mechanical and thermal durability properties. This group of minerals can be used in ceramic industry, in detergent industry, and as neutron shielding material, phosphor of thermoluminescence by dint of their extraordinary specialties. In the present study, the synthesis of magnesium borate via hydrothermal method from sodium borates and physical properties of synthesized magnesium borate minerals were investigated. The characterization of the products was carried out by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies, and differential thermal analysis and thermal gravimetry (DTA/TG). The surface morphology was examined by scanning electron microscopy (SEM). B2O3content was determined through titration. The electrical resistivity/conductivity properties of products were measured by Picoammeter Voltage Source. UV-vis spectrometer was used to investigate optical absorption characteristics of synthesized minerals in the range 200–1000 nm at room temperature. XRD results identified the synthesized borate minerals as admontite [MgO(B2O3)3·7(H2O)] with code number “01-076-0540” and mcallisterite [Mg2(B6O7(OH)6)2·9(H2O)] with code number “01-070-1902.” The FT-IR and Raman spectra of the obtained samples were similar with characteristic magnesium borate bands. The investigation of the SEM images remarked that both nano- and microscale minerals were produced. The reaction yields were between 75.1 and 98.7%.

In this study, sonochemical-assisted magnesium borate synthesis is studied from different boron sources. Various reaction parameters are successfully applied by a simple and green method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies are used to characterize the synthesized magnesium borates on the other hand surface morphologies are investigated by using scanning electron microscope (SEM 01-070-1902. The results that found in the spectroscopic studies were in a good agreement with characteristic magnesium borate bands in both regions of infra-red and visible. According to SEM results, obtained borates were in micro and sub-micro scales. By the use of ultrasonication, reaction yields were found between 84.2 and 97.9%. As a result, it is concluded that the sonochemical approach is a practicable synthesis method to get high effi ciency and high crystallinity in the synthesis magnesium borate compounds.

Bergama is the first gold mine in the history of Turkish Republic and currently one of the operating gold mine in Turkey. About 3 tons of gold and equal amounts of silver are mined each year. The estimated ore reserves at the Bergama gold mine are 2.4 million tons with about 10 g Au per tonne of ore. About 277.882 tons of the tailings slurry of gold mine treatment is produced every year during the recovery of gold. Increasing amounts of tailings slurry cause a problem in large disposal areas. Therefore, the recycling of this kind of slurries into useful materials is quite important in terms of economic and environmental aspects.The aim of this study was the investigation of utilization of the gold tailings as an additive material in Portland cement production. For this purpose, the effects of the gold tailings on the compressive strength properties of Portland cement were investigated. Cement mortars were prepared with Portland cement (CEM I 42,5 N) and dried gold tailings. Gold tailings with different ratios (5, 10, 15, 20, 25%) were added as cement additive in the mortar. The fresh properties of mortar such as consistency and setting time were investigated by using Flow table and Standard Vicat apparatus. The mortars were tested for compressive and flexural strength values after 3, 7 and 28 days. Mineralogical composition and microstructure of the 28-day mortars were determined by X-ray diffraction (XRD) and scanning electron microscope (SEM). According to results, it can be concluded that the tailings are eligible for mortar aggregate and the optimum ratio of gold tailings is 5%.

Borax sludge is the waste produced by a trommel sieve in the borax production process and is used as an adsorbent for Cr(III) removal. The effects of various parameters, including pH, initial Cr(III) concentration and contact time were investigated for batch adsorption of Cr(III). The experimental results obtained were applied to different adsorption isotherms and kinetic models. The results indicated that the Temkin isotherm (R 2 = 0.9749) was most suitable to explain the adsorption characteristics of borax sludge, and the removal of Cr(III) was achieved by a physisorption process. The overall kinetic data fitted the pseudo-second order rate model (R 2 = 0.9990). According to thermodynamic studies, which were carried out at different temperatures, changes in enthalpy (ΔH) and entropy (ΔS) values for Cr(III) adsorption by borax sludge were determined to be 69.395 kJ/mol and 0.276 kJ/mol K, respectively. The study implied that borax sludge could be used as an alternative adsorbent in the adsorption of Cr(III) from aqueous solutions.

Turkey has 955,297 thousand tonnes of B2O3 reserves which correspond to 72.1% of the world. Colemanite (Ca2B6O11•5H2O), ulexite (NaCaB5O9•8H2O) and borax (tincal) (Na2B4O7•10H2O) are the most important boron minerals that are used in production of boric acid and different kinds of borates. During these production processes, boron including wastes form and these wastes pollute the environment. To minimize the pollution caused by these wastes, they are evaluated in different kinds of processes such as cement and concrete production. Borogypsum is one of the boron wastes that is used in cement mortar production.In this study the aim was to compare the calcined and non-calcined borogypsum addition to clinker and also investigate its effects on cement mortar. Moreover, to see how borogypsum addition affected the cement properties, different ratios of borogypsum between 1% and 7% were used. Also setting time and consistency analyses were applied to fresh mortar; compressive strength and splitting tensile strength of 3, 7, and 28 days were investigated according to the Turkish Standard (TS EN 196-1). X-ray diffraction (XRD) analysis was realized for characterization of the chemical structure of 28-days mortars. 3% was the ratio at which the optimum results were obtained for both calcined and non-calcined borogypsum.