The main chemical properties of hot and cold mineral waters in Bayankhongor, Mongolia

In the current study, hot and cold mineral springs and sub mineral waters in the Bayankhongor province were examined for their chemical characteristics and identified cold mineral waters classification according to mineral water classification of Mongolia. The hot spring waters belong to Na+-HCO3- and Na+-SO42- types. The cold mineral spring of Lkham belongs to Ca2+-HCO3- type. All sub mineral waters are generally located in the two areas (northern part or mountain forest area and the southern part or Gobi desert area). TDS concentrations of cold springs of the southern part in the study area were higher than northern part’s cold springs. The total dissolved silica content of cold spring was ranged from 4.5mg/L to 26 mg/L which did not correspond to requirements of mineral water standard of Mongolia. Thus, these cold springs are belonging to sub mineral water classification. The sub mineral waters were characterized into four types such as a Ca2+-SO42-, Na+-SO42-, Na+-HCO3 and Ca2+ - HCO3 by their chemical composition in the study area. The values for the quartz, chalcedony geothermometer and the Na/K geothermometer were quite different. The silica-enthalpy mixing model predicts a subsurface reservoir temperature between 124 and 197°C and most of the hot waters have been  probably mixed with cold water. The result shows that an averaged value of calculated temperature ranges from 77°C to 119°C which indicates that studied area has low temperature geothermal resources. DOI: http://doi.dx.org/10.5564/mjc.v15i0.324 Mongolian Journal of Chemistry 15 (41), 2014, p56-6

Characterisation of fly ashes from 4th Thermal Power Station of Ulaanbaatar city and its applicability for a zeolite synthesis

Fly ash from 4th thermal power station of Ulaanbaatar city have been characterised by x-ray fluorescence (XRF), x-ray diffractometry (XRD), particle size analyzer, specific surface area measurement (BET) and scanning electron microscope (SEM) observation. It was found that fly ash from Baganuur coal contains over 15 wt.% of calcium oxide (CaO) and could be assigned as class C fly ash, according to the International classification. Specific surface area of this fly ash was 2.75 m2/g and mean particle diameter was 59.5 μm. Zeolitic compounds were synthesised by using mixture of this fly ash and a transition aluminium oxide under hydrothermal treatment at 100, 150 and 200°C temperatures for a different duration. Various zeolitic compounds including Na-faujasite and sodium aluminosilicate were synthesised as reaction products.DOI: http://dx.doi.org/10.5564/mjc.v12i0.164 Mongolian Journal of Chemistry Vol.12 2011: 16-19

Characterization of ash pond ashes from 3rd thermal power plant by SEM/EDX and XRD methods

  Coal combustion by products from ash pond of 3rdthermal power plant of Ulaanbaatar city have been collected in 2010 and 2013 years. The ash samples have been characterized by XRD, XRF and SEM-EDX methods in order to evaluate their chemical and mineralogical composition changes with disposed times. The mineralogical composition of ash varies with time though the chemical composition of the ashes were close each other. Possibly, inefficient operating condition of the TPS shows influence on the mineralogical composition.DOI: http://dx.doi.org/10.5564/mjc.v14i0.201Mongolian Journal of Chemistry 14 (40), 2013, p61-6

The mechanochemical activation study of Tsagaan-tsav zeolite

Characterisation of mechanochemically activated Tsagaan-tsav zeolite has been performed. Tsagaan-tsav zeolite has been activated with a vibration mill for 2, 3, 5, 10 and 20 minutes. Ball to powder ratios were varied 1:10, 1:20, 1:50 and 1:100. Efficiency of milling determined based on amorphisation rate and cation exchange capacity changes. The highest efficiency was obtained for zeolite milled with ball to powder ratio of 100. Structural characterisation was performed with XRD, SEM, BET and particle size analyzer. Mechanochemical activation improves cation exchange capacity of natural zeolite.DOI: http://dx.doi.org/10.5564/mjc.v12i0.181 Mongolian Journal of Chemistry Vol.12 2011: 98-101

Properties of geopolymer binders prepared from milled pond ash

Alkali-activated materials were prepared from pond ash from the Darkhan city (Mongolia) thermal power station. This ash contains about 60 wt % X-ray amorphous material in addition to quartz, mullite, hematite and magnesioferrite, and presents significant storage problems since it is accumulating in large amounts and is a hazardous waste, containing 90-100 ppm of the heavy metals As, Pb and Cr, and about 800 ppm Sr. Alkali-activated materials synthesized from the as-received pond ash achieved compressive strengths of only 3.25 MPa. Reduction of the particle size by mechanical milling for up to 30 min progressively increases the compressive strength of the resulting alkali-activated geopolymer up to 15.4 MPa. Leaching tests indicate that the combination of milling and alkali treatment does not cause the release of the hazardous heavy metals from the product, making it suitable for construction applications. © 2017 CSIC

Preface Vol.12

DOI: http://dx.doi.org/10.5564/mjc.v12i0.161 Mongolian Journal of Chemistry Vol.12 201

Preface Vol.13

DOI: http://dx.doi.org/10.5564/mjc.v13i0.150 Mongolian Journal of Chemistry Vol.13 201

Characterisation of various fly ashes from Australia and Mongolia and their utilisation for preparation of Geopolymers with advanced applications

Fly ashes from different power stations of the Australia (Collie, Eraring, Tarong) and Mongolia (Darkhan, 3rd and 4th thermal power stations, Ulaanbaatar city) have been characterised by different techniques. It was determined that the Australian fly ashes are class F while most of Mongolian fly ash is class C. Due to their chemical and mineralogical differences the fly ashes behave differently when alkali activated to make geopolymers. The influences of various parameters on the preparation of geopolymers have been investigated and established for routine manufacture. The applicability of using fly ash for building structural elements, acid and alkaline resistant products and thermal resistance materials will be presented

Porous Properties of Silica Prepared by Selective Acid Leaching of Heat-Treated Vermiculite

The porous properties of silica prepared from heat-treated Transvaal vermiculite (South Africa) by acid leaching were determined. The effect of temperature on the destruction of the crystal structure of the vermiculite was determined, leading to the adoption of heating conditions of 600 o C for 2 h which produce a fully amorphous sample. The heat-treated samples were leached with 2M hydrochloric acid at 80 o C for 0.5, 2 and 8 h and their porous properties were characterized by measuring their specific surface areas and pore volumes. The highest surface area and pore volume (559 m2/g and 0.51 ml/g) was obtained for the sample leached for 8 h. Thermal amorphisation of vermiculite exerts a negative influence on the porous properties of the mineral