Vario macro chn

The atomic structure of the obtained materials was analyzed using a high-resolution transmission electron microscope (HRTEM FEI Tecnai F20 X-Twin, Brno, Czech Republic) at an accelerating voltage of 200 kV. A scanning electron microscope operating at 30 kV (SEM, 1430 VP, LEO Electron Microscopy Ltd., Oberkochen, Germany) was used to determine the structure of the samples. The elemental composition of the materials was analyzed by means of a combustion elemental analyzer (Vario MACRO CHN, Elementar Analysensysteme GmbH, Langenselbold, Germany). Raman-microscopic spectroscopy analysis was performed using Renishaw InVia (Renishaw Company, Gloucestershire, the United Kingdom), excitation wavelength 532 nm at an ambient temperature. Nitrogen sorption isotherms were determined through nitrogen physisorption at 77 K in a volumetric apparatus ASAP 2010 (Micromeritics, Norcross, GA, USA). The attachment, bonding configuration, and compositional analysis of the material was carried out by X-ray photoelectron spectroscopy measurements (XPS, PHI5000 VersaProbe II Scanning XPS Microprobe, Chigasaki, Japan). A monochromatic Al-Kα X-ray (1486.6 eV) was used as the operating excitation source. Atomic Force Microscopy (AFM) investigations were conducted using a Scanning Probe Microscope (SPM) apparatus produced by Veeco (Digital Instrument, USA), working under ambient conditions.

A low-rank coal sample was collected from Pingshuo power generation plant in Shanxi Province, China. Proximate analysis and ultimate analysis of the coal sample were performed using a thermogravimetric analyzer (TGA-701, LECO) and an elemental analyzer (vario Macro CHNS, Elementar), respectively, and the calorific value was determined by an adiabatic bomb calorimetry (Parr 6400 Calorimeter, Parr). The results obtained are summarized in Table 2. Additionally, the chemical compositions of the coal ash were determined by X-ray fluorescence (XRF) spectrometer (S4-Explorer, Bruker) and the results are detailed in Table 2. The coal sample was first dried for 24h at 105 ^oC and then crushed and ground to a size smaller than 150 um.
Industrial steel slags were acquired from Shougang Corporation in Beijing, China, the chemical compositions of which were measured by XRF (S4-Explorer, Bruker) and displayed in Table 2. The slag was first crushed into small particles after drying, and then thoroughly mixed with the coal powder using a ball grinder for the subsequent gasification. Three samples were prepared using the foregoing materials, i.e., a raw steel slag sample (S0), a raw coal sample (S1) and a mixture with the mass ratio of coal sample to steel slags of 1:1 (S2), respectively.