Mongolian Journal of Chemistry <p>Published by the Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences.</p><p>The Mongolian Journal of Chemistry is included on <a title="DOAJ" href="" target="_blank">DOAJ</a> and the <a title="EBSCO" href="" target="_blank">EBSCO Discovery Service</a> and <span>CAS databases</span></p> en-US <p>Copyright on any research article in the Mongolian Journal of Chemistry is retained by the author(s).</p><p>The authors grant the Mongolian Journal of Chemistry a license to publish the article and identify itself as the original publisher.</p><p><a href="" rel="license"><img style="border-width: 0;" src="" alt="Creative Commons Licence" /></a><br />Articles in the Mongolian Journal of Chemistry are Open Access articles published under a <a href="" rel="license">Creative Commons Attribution 4.0 International License</a> CC BY.</p><p>This license permits use, distribution and reproduction in any medium, provided the original work is properly cited.</p> (Academician J. Temuujin) (Gantulga Lkhagva) Mon, 04 Mar 2019 00:00:00 +0000 OJS 60 Preface <p>No abstract in English</p> Jadambaa Temuujin, Enkhtuul Surenjav, Namjil Erdenechimeg ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 Leaching of a Mongolian chalcopyrite concentrate <p>A Mongolian chalcopyrite flotation concentrate was leached using sodium hypochlorite adjusted to different pH using hydrochloric acid. It was found that using a starting pH of below 5.0 resulted in more efficient leaching. The extent of chalcopyrite leaching was determined by the concentration of sodium hypochlorite with &gt; 40% dissolution being achieved. The residue after leaching was found to consist primarily of unreacted chalcopyrite which would be suitable for further leaching or smelting.</p> Nicholas J Welham, Jadambaa Temuujin, Nader Setoudeh ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 High molecular weight humic-like substances in carboneous aerosol of Ulaanbaatar city <p>Total carbon content of the atmospheric suspended particulate matters consisted of as high as 89-93% organic carbon (OC) in Ulaanbaatar aerosol without showing seasonal variation. However, limited aerosol measurements have been conducted on these OC rich aerosols particularly for high molecular weight constituents. In order to address the gap above, abundance of high molecular weight humic-like substances (HULIS) in total suspended particulates (TSP) from Ulaanbaatar atmospheric aerosol were determined for the first time. HULIS molecular structure was characterised for different seasons using carbon content and UV absorbance measurements coupled with solid phase extraction methods. Although, HULIS contributions to water soluble organic fraction of the winter and summer aerosols were similar HULIS carbon concentration was higher in winter samples (9-37 mg·L<sup>-1</sup>) than in summer (2-6 mg·L<sup>-1</sup>). Consequently quantity of aromatic moieties and degree of aromaticity varied between seasons.</p> Shurkhuu Tserenpil, Xing Jung Fan, Atindra Sapkota, Enkhmaa Chinzorig, Jian Zhong Song, Cong Qiang Liu ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 Effect of nickel precursor and catalyst activation temperature on methanation performance <p>This work studied an effect of anionic precursor on the preparation of active and fine nickel metal catalysts for syngas methanation. Nickel catalysts were pr¬epared by impregnation-co-precipitation method. Nickel hydrate salts of Ni(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O, NiSO<sub>4</sub>·6H<sub>2</sub>O and NiCl<sub>2</sub>·6H<sub>2</sub>O were used as a metal catalyst precursor, and the obtained catalysts were named as Ni/Al (N), Ni/Al (S) and Ni/Al (Cl), respectively. Methanation synthesis of carbon monoxide was carried out in a fixed bed stainless reactor. Prior to experiment, the catalyst powder was pressed into tablets, then crushed and sieved to use 0.5-0.9 mm particles. Reactions were performed at the temperature of 350 °C in the pressure of 3 atm of H<sub>2</sub>:CO syngas (the molar ratio of 3:1) with the GHSV of 3000 h<sup>-1</sup>. In the present methanation conditions, the Ni/Al (N), Ni/Al (S) and Ni/Al (Cl) catalysts gave the CH4 selectivity of 93%, 18% and 91% (vol.), respectively. The XRD and ICP-OES analysis clarified that although the Ni/Al (S) catalyst contained a similar nickel amount of 17.4 wt % to other two catalysts, its metal distribution was poor. Also the low activity of the Ni/Al (S) catalyst was caused by the contamination of remained sulfur from sulfate precursor. This work also examined an influence of catalyst activation temperature pre-synthesis. The Ni/Al (N) catalyst was reduced by pure hydrogen gas at different temperatures of 350 ºС, 400 ºС or 450 ºС. The catalyst activated at 400 ºС produced the highest CH4 amount of 0.087 mmol·g-1cat for the duration of 1h methanation. An initial temperature of methane formation was the lowest for the Ni/Al (N) catalyst which was activated at 400 ºС among three catalysts.</p> Battulga Buyan-Ulzii, Odbayar Daariimaa, Chuluunsukh Munkhdelger, Galindev Oyunbileg, Byambajav Enkhsaruul ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 Characterization and thermogravimetric analysis of oil shale from Uvurjargalant deposit <p>The yield, properties and composition of soluble and insoluble (kerogen) of organic matter of oil shale from Uvurjargalant deposit of Mongolia have been investigated in this study. The study result shows that oil shale contains low amount of moisture and volatile products, while the ash yield is high (71.86 %) - which implies that most of the oil shale are minerals. The total amount of bitumens in the oil shale was very low (1.27 wt %), whereas kerogen content was 22.84 wt %, which is relatively high compared to oil shale from other deposits in Mongolia. Under IR spectral analysis and the ratio of hydrogen and carbon, the Uvurjargalant oil shale belongs to I type of oil shale. The thermogravimetric analysis showed that organic matter of oil shale decomposed at a temperature 300-750 ºC to produce gas and liquid products.</p> Khulan Bayasgalan, Myagmargerel Bayanmunkh, Ulzii Baatar, Bolormaa Bayarkhuu, Tuya Murneren ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 Pyrolysis of pine wood and characterisation of solid and liquid products <p>Pyrolysis of pine wood was carried out at different temperatures and the yields of solid (biochar), liquid (tar and pyrolysed water) and gas products were determined. Temperature around 500 ºC was determined as an optimal heating temperature of pyrolysis and approximately 27.1% hard residue (biochar), 21.46% tar, 20.04% pyrolysed water and 31.30% gas were obtained by pyrolysis. The thermal stability indices of pine wood are relatively low, which are indications of its low thermal stability and high yield of volatile matter (V<sup>daf</sup> = 90.3%). The thermal stability indices of pyrolysis of solid residue show that it is characterised by a very high thermal stability than its initial sample, for example, there was an increase of Т<sub>5</sub>% 7.7 and Т<sub>15</sub>% 3.8 times. The chemical composition of pyrolysed tar of pine wood has also been determined. Were obtained 4 different fractions with varying boiling temperature ranges of pine wood pyrolysed tar and have determined the yields of each fraction. Neutral tar was analysed by GC/MS and 20 aliphatic compounds, 25 aromatic compounds and 18 polar compounds were determined.</p> Barnasan Purevsuren, Otgonchuluun Dashzeveg, Ariunaa Alyeksandr, Narangerel Janchig, Jargalmaa Soninkhuu ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 Functional properties of fermented soymilk by Lactobacillus fermentum BM-325 <p>Soy products have attracted much attention recently as carriers for probiotics. Fermentation of soymilk with lactic acid bacteria (LAB) was found to improve the nutritional and bioactivity values of consumed foods. The aim of this study was to evaluate functional properties of fermented soymilk with probiotic LAB strain <em>Lactobacillus </em>fermentum BM-325, based on their growth behavior, enzymes and antioxidant activities. Growth behavior such as viable cell number, pH, total acidity and enzyme activities were determined during fermentation period. Maximum number of viable cell was Log<sub>10</sub> CFU·ml<sup>-1</sup> 12.6±0.9, maximum β-glucosidase activity was 78.9±3.9 U·mg<sup>-1</sup> and maximum α-galactosidase activity was 97.7±4.8 U·mg<sup>-1</sup>, as well as antioxidant activity was IC<sub>50</sub> 0.04±0.002 mg·mL<sup>-1</sup>. Angiotensin converting enzyme inhibitory (ACEI) activity was determined in fermented soymilk and in partially purified peptide fraction. The ACEI activity was reached 60% after 20 h fermentation in soymilk. Our results suggested that fermentation of <em>Lactobacillus </em>fermentum BM-325 in soymilk for 4 h could be used to increase bioactivity of soymilk and suitable for the development of functional food.</p> Batmunkh Myagmardorj, Munkh-Erdene Purev, Batjargal Batdorj ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 Chemical composition and antimicrobial activity of essential oil from <i>Pyrethrum pulchrum</i> Ledeb. <p>The chemical composition and antimicrobial activity of the essential oil from the aerial parts of <em>Pyrethrum pulchrum</em> Ledeb. were investigated. Dried plant material was hydro-distillated yielding 0.1% of essential oil. The oil was analyzed by GC-MS techniques. Fifty-five compounds were identified representing 99.7% of the total oil composition. Camphor was the predominant compound (33.9%) followed by linalool (21.1%) and α-pinene (9.0%). The antimicrobial activity of the oil was determined using the disk diffusion method against Gram-positive bacteria (<em>Bacillus subtilis, Staphylococcus aureus</em> and <em>Enterococcus faecalis</em>), Gram-negative bacteria (<em>Pseudomonas aeruginosa </em>and<em> Escherichia coli</em>), <em>Mycobacterium vaccae</em> and fungi (<em>Candida albicans, Sporidiobolus salmonicolor</em> and<em> Penicillum notatum</em>). The essential oil of <em>P. </em>pulchrum displays an intermediate activity against selected bacteria.</p> Uugangerel Erdenetsogt, Choijamts Gotov, Kerstin Voigt, Stefan Bartram, Wilhelm Boland, Enkhmaa Dagvadorj ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 Enhancing lithium leaching by mechanical activation <p>The lithium (Li) bearing minerals lepidolite and spodumene were mixed with different mass ratios of Na<sub>2</sub>SO<sub>4</sub> and mechanically activated by milling in a planetary ball mill for 5 h. The milled samples were studied using thermogravimetry under an air atmosphere up to 950 ºC. Isothermal heating of the milled samples was undertaken in a furnace at temperatures of 700 ºC and 800 ºC for 1 h. Hot water leaching of the calcines indicated that increasing the calcination temperature had a significant effect on the dissolution of lithium. The leaching of lithium from lepidolite was notably higher than that from spodumene.</p> Nader Setoudeh, Ataollah Nosrati, Nicholas J Welham ##submission.copyrightStatement## Fri, 28 Dec 2018 00:00:00 +0000 Retraction notice: Influence of compressing pressure on macro void formation carbon monolith for methane adsorption <p>RETRACTION NOTICE<br>On 21rd February 2019, the Editorial Board of the Mongolian Journal of Chemistry decided to retract this article entitled "Influence of compressing pressure on macro void formation of carbon monolith for methane adsorption" because of an authorship dispute. The article was originally published in Vol.18 No.44 2017 pp.24-35. doi:</p> Narandalai B, W G Shim, M S Balathanigaimani, H Moon ##submission.copyrightStatement## Thu, 28 Feb 2019 16:56:18 +0000