Preparaton of nano-structured strontum carbonate from Dasht-e kavir celestte ore via mechanochemical method Erfan Alimohammadi, Saeed Sheibani*, Abolghasem Ataie School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran. Recieved: 28 October 2017; Accepted: 28 Aprile 2018 * Corresponding author email: ssheibani@ut.ac.ir ABSTRACT Keywords: Strontum carbonate; Celestte ore; Nano-structured; Mechanochemical. Journal of Ultrafne Grained and Nanostructured Materials https://jufgnsm.ut.ac.ir Vol. 51, No.2, December 2018, pp. 147-152 Print ISSN: 2423-6845 Online ISSN: 2423-6837 DOI: 10.22059/JUFGNSM.2018.02.06 In the present investgaton, nano-structured strontum carbonate was synthesized by mechano-chemical reacton of raw mineral celestte ore (SrSO 4 ) collected from Dasht-e kavir, Iran, without inital acid leaching and chemical benefciaton, and sodium carbonate during high energy mechanical milling. X-Ray difracton (XRD), X-ray fuorescence spectrometer (XRF), atomic absorpton spectroscopy (AAS) and scanning electron microscope (SEM) were used to characterize the obtained samples. XRD results showed that at a Na 2 CO 3 :SrSO 4 molar rato of 1.05:1, mechano-chemical reacton started afer 1 hour of milling. Although the longer milling tmes gives a more conversion of SrSO4 to SrCO 3 but it has not been completed even afer 16 hours of milling. However, by increasing the molar rato of Na 2 CO 3 :SrSO 4 to 1.25:1, the SrCO 3 formaton was completed afer 2 hours. The results also showed that the mean crystallites sizes of produced nano- powder were approximately 32 nm. XRF result indicated that the fnal product was obtained with a purity of 95 wt.%. AAS results specifed that the recovery rate for producton of SrCO 3 from celestte concentrate was about 97%. SEM studies confrmed the formaton of SrCO 3 nano-powder with a mean partcle size of 80 nm. 1. Introduction Strontium carbonate (SrCO 3 ) is one of the most important strontium compounds that have been used in a variety of technological and industrial applications. It is particularly used as an additive in the fabrication of glass cathode-ray tubes for TV and computer monitors (more than 65% of total production) and as a constituent of magnetic ferrites (more than 20% of total production). Other applications are in the manufacturing of special glasses, in pyrotechnics, paints, medicine and photocatalysts such as strontium titanate and zirconate for aqueous degradation of organic pollutants and advanced ceramic materials. Although SrCO 3 occurs naturally as mineral strontianite, most of it that is available has been produced from celestite ore (SrSO 4 ) that is the only commercially exploited strontium mineral [1-3]. Tere are two commercial processes to manufacture SrCO 3 from celestite; the black ash and the double decomposition (direct conversion) processes. In the black ash process, SrSO 4 is reduced with coke (or coal) at temperatures generally over than 1000 °C to produce water soluble SrS. Te sulfde is then leached in hot water and strontium carbonate is precipitated using soda ash, ammonium bicarbonate and/or CO 2 [4-7]. In the second process, finely powdered celestite is reacted with hot sodium carbonate solution (>90 °C) to obtain SrCO 3 and by-product sodium