Papers by Keyword: Antimony

Abstract: Archaeometallurgical copper-artefacts contain a wide variety of metal admixtures (e.g. Pb, Bi, As, Sb, Sn) which either originate from the ores or were intentionally added. When the melt solidifies, these elements can accumulate in different structural areas and form special phases. The different alloying elements also interact with each other. In order to be able to examine these interactions, model alloys with different elements (Pb, Bi, As, Sb, Sn) and concentrations (5 or 10 wt.% each) were produced. More simple alloys show a dendritic microstructure and the added elements accumulate in the interdendritic areas. This is clearly visible for Pb and Bi additions, as both metals are not soluble in copper. As and Sb form compounds with Cu which precipitate mainly in the interdendritic regions. Sn is soluble in Cu at lower concentrations and Cu-Sn phases are formed only at higher concentrations. The resulting microstructures become very complex if more elements are involved. Finally, they enable us to have a better understanding for microstructures of ancient copper alloys.

Abstract: Antimony tin oxide coating research has been carried out using a spin sol gel coating method with different doping concentrations (0, 5, 10, 15, 20)%. The results of the study on the morphological structure (SEM) of thin films that have been carried out showed more cracks on the surface of the morphology of thin layers without doping compared to thin layers with doping antimony. The Results of crystal structure of XRD in thin antimony doping tin oxide layer shows the grinding index of tin oxide crystals, 101, 110, 211, 220. In grain size, with increasing antimony doping percentage, the average grain size decreases. The optical properties using UV-Vis in thin films of antimony tin oxide doping show samples including semiconductor materials that can be used as electronic devices as seen from the reduction of this energy gap (3,680 - 3,574) eV. Also seen is an increase in the percentage of antimony doping and repetition of layers, the lower the transmissions value, but the value of absorbance of the thin layer increases.

Abstract: The phase equilibria in the ternary systems {Ce, Gd}–{Ti, Zr}–Sb were investigated by means of X-ray powder diffraction and energy-dispersive X-ray spectroscopy. The isothermal sections of the phase diagrams at 600°C were constructed. The formation of three ternary compounds (Ce₂Ti₇Sb₁₂, Ce₃TiSb₅, and Gd₂Ti₁₁Sb₁₄) was confirmed in the {Ce, Gd}–Ti–Sb systems and no more ternaries were found. The investigation of the {Ce, Gd}–Zr–Sb systems revealed several new ternary compounds and confirmed the known ones. The crystal structure of the new compound Ce_0.08(3)Zr_1.92(3)Sb was determined from X-ray powder diffraction data. The other new compounds in the Ce–Zr–Sb system were found to have compositions close to ~CeZrSb₄ and ~Ce₂Zr₃Sb₅. In the Gd–Zr–Sb system the existence of a large homogeneity range was established for the GdZrSb compound along the isoconcentrate 33.3 at.% Sb: Gd_1-xZr_1+xSb (x = 00.905(18) at 600°C), and a new compound, ~Gd₃Zr₃Sb₁₄, was discovered. The crystal structures at the boundary compositions of the Gd_1-xZr_1+xSb phase were refined from X-ray powder diffraction data.

Abstract: This paper details the hydrometallurgical method of processing of refractory gold antimony flotation concentrate. Investigation of feed material has been occurred. Mineralogical analyses (XRD, SEM-EDS) and chemical analyses of the concentrate have been studied. Mainly, the material consists of compounds of antimony, silicon, calcium, sulfur and iron. The main phases are quartz, stibnite, calcium carbonate and ankerite, pyrite and arsenopyrite have been found as well. The feature of antimonite’s dissolving in alkaline solutions has been reviewed. The dependences of effects of the temperature, time, L/S ratio and NaOH concentration on the antimony and sulfur extraction from the feed flotation concentrate have been determined. During alkaline sulphide leaching of the starting material several physicochemical characteristics of gold dissolution have been identified. Agitated cyanide gold leaching test of the pre-treated cake was conducted. Gold recovery was 32.2%. The obtained low indexes of gold recovery are based on cyanidation. A nitric acid leaching of disantimonied cake was proposed.

Abstract: Case hardened, double-walled train wheel, produced in the foundry of Abraham Ganz in 1867 and used for long time on the railroad tracks, was studied and evaluated by modern methods of materials sciences. The investigations indicated the presence of 0.059m% antimony (Sb), distributed uniformly in the material of the wheel. This quantity is several times higher than the average Sb amounts (<0.01m%) of the other components get into the castings. Sb was detected even in the several mm thick crust; except in the outermost surface layer with < 1 µm thickness. Based on the 20th century comprehensive studies, the antimony content, detected in the wheel, was found to be ideal. In grey iron it is a powerful pearlite stabilizer which has favourable effects on its mechanical properties and serviceability.The investigation of the surface structure proved that the excellent hardness (~600 HV) at the crust surface was due to the “nano-composite” structure formed from the pearlite as a consequence of severe plastic deformation during service. This was also promoted by the high amount (4.09m%) of carbon present in the casting. The microstructure refinement during operation most probably contributes to the long service lifetime of the wheels.The secret of the Abraham Ganz’s train wheels is inherently present – besides the novel construction and production technology (case hardening) – in the above mentioned composition and the structure of the material.

Abstract: Pb–free solders have been widely developed by materials researchers as mainly focused on the replacement for Sn–Pb eutectic solder. In this study, Sn–3.0Ag–0.5Cu, Sn–3.0Ag–0.5Cu–xSb and Sn–3.0Ag–0.5Cu–xZn solders (x = 1.0, 2.0 and 3.0 wt%) were prepared using melting method. The effect of Sb and Zn addition on microstructure and properties, such as tensile strength, microhardness and corrosion resistance of Sn–Ag–Cu solders was investigated. The microstructure analysis revealed that addition of Sb and Zn to the Sn–Ag–Cu solders obviously decreased phase fraction of the dendritic β–Sn phase and the finer eutectic phase was obtained, resulting in superior mechanical properties of the Sn–3.0Ag–0.5Cu–xSb and Sn–3.0Ag–0.5Cu–xZn solders compared to the Sn–3.0Ag–0.5Cu solder. The results of potentiodynamic polarization tests indicated that the corrosion potentials of the Sn–3.0Ag–0.5Cu–xSb solders continuously increased with increasing of Sb content. While Zn content had little effect on the corrosion potentials of the Sn–3.0Ag–0.5Cu–xZn solders.

Abstract: Arsenic, antimony and bismuth in gold ores were simultaneously determined by inductively coupled plasma optical emission spectrometry (ICP-OES) with spectral lines of 188.980, 206.834 and 223.061nm as analytical line respectively, under preset instrumental parameters. The linear range of the method for arsenic, antimony and bismuth was 0~80ug/mL and the correlation coefficient was greater than 0.99995. The detection limit for arsenic, antimony and bismuth was 2.87, 1.63 and 0.84ug/g respectively. The results of this method are consistent with the national standard method, and the relative error is less than 1.5%. The relative standard deviation (RSD) of this method is better than 5.0% (n=11) with good accuracy and precision. ICP-OES can be used for simultaneous determination of multiple elements and is suitable to the analysis of large quantities of samples.

Abstract: The modification mechanism of Sb on eutectic Si phase of Al-Si alloys was not understood very well. In this paper the modification effects of Sb on Al7SiMg alloy were investigated by computer aided cooling curve thermal analysis coupled with microstructure observation. The results show that the addition of Sb with 0.1%~0.25% amount has refining effect on eutectic Si phase, and this modification effect can be recorded by the cooling curve. The addition of Sb decreases the growth temperature of the eutectic solidification (T_EG) by 5.0 °C to 7.8 °C, and this indicates that there is an undercooling effect with Sb modification. Moreover, faster cooling rate can obtain more superior morphology of eutectic Si, which can be changed from short rod to nearly granular particles. The morphology of eutectic Si is nearly unchanged with holding time extending from 0.5h to 2.5h, which means Sb has long modification effect for Al-Si alloys.

Abstract: Sb is an effective additive to modify eutectic Si of Al-Si alloys and the modification mechanism has not yet been studied very clearly. In this paper, computer aided cooling curve thermal analysis and microstructure assessment were carried out to investigate the modification effects of Sb on Al7SiMg alloy. The results show that the Sb addition amount of 0.1~0.25% has improvement effect on eutectic Si morphology, which can be further confirmed from the thermal analysis results. The addition of Sb decreases the eutectic growth temperature by 5 °C to 7.8 °C, indicating an undercooling effect resulted from Sb modification. Compared to that of short rods, a better eutectic Si morphology of nearly granular particles can be obtained in a faster cooling rate. The length of silicon has been gradually shortened as holding time increased to 2.5 h from 0.5 h, which means a long period modification effect of Sb in Al-Si alloys. Owing to undercooling resulted from Sb addition in Al-Si alloys, the refinement structure of eutectic silicon can be achieved.

Abstract: This article presents the effect of individual addition of Sb, Sn and Pb on the precipitation sequence at room as well as high temperature tensile properties of AZ91 alloy. The results show grain refinement, formation of Mg₃Sb₂ and Mg₂Sn phases when Sb and Sn are added to AZ91 alloy. Lamellar precipitate is significantly suppressed while Pb added. Improved room and high temperature tensile properties are observed in Sb and Sn addition. Maximum tensile properties are noticed with AZ91 alloy having 0.5 wt.% Sb addition.