scholarly journals Characterization and leaching of mechanically activated zinc residue

2021 ◽  
Author(s):  
M. Deniz Turan
Keyword(s):  
Grain Size ◽  
Ball Mill ◽  
Xrd Analysis ◽  
Original Sample ◽  
Zinc Extraction ◽  
Peak Intensity ◽  
Mineral Phases ◽  
Solid Liquid ◽  
Grinding Time ◽  
Sem Analyses

AbstractZinc extraction from zinc-containing residual (ZCR) was examined with the leach of sulfuric acid of original materials and the materials milled in two different mill systems. For this purpose, vibrating ball mill (VBM) and ring mill (RM) were used. In chemical analysis of ZCR, it was determined that it contains a significant amount of zinc, lead, iron and silver and consisted of mostly CaSO4.2H2O, PbO, SiO2, Fe2O3, ZnFe2O4, Al2FeO4 and PbSO4 mineral phases. It was determined in XRD analysis of samples milled at both mills that peak intensity dramatically decreased when compared to original sample.According to comparative characterization analyses of the milled samples, it was determined that through the increasing grinding time, the particles became agglomerated and an increase in grain size occurred. This situation was also supported by N2-BET and SEM analyses.While zinc extraction value of the sample milled for 1 min, which was obtained at 0.5 M H2SO4 at leach temperature of 25 °C, at the solid–liquid rate of 100:1 and during the leach time of 30 min, was 90% and 60% for, respectively, VBM and RM, zinc of 54% was determined to be extracted in the leach of the original sample, under the same conditions.

scholarly journals Preparation of C4-silica Gels from Waste Glass and Tributylamine

POSITRON ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 69
Author(s):  
Nelly Wahyuni ◽  
Rudiyansyah Rudiyansyah ◽  
Mellisa N. Safitri
Keyword(s):  
Sodium Silicate ◽  
Xrd Analysis ◽  
Waste Glass ◽  
Silica Gels ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Peak Intensity ◽  
Near Future ◽  
Oxygen Bond ◽  
Sem Analyses

Waste glass materials coming from municipal and industrial processes have become a serious problem for the environment in the near future. Silica gels have been long attracting attention since it is widely used for many applications. It had also been studied by several fields because of its surface properties. In this study, semi-polar silica gels have been synthesized. C4-silica gels have been prepared by reaction between tributylamine (TBA) and silica gels produced from waste glass. The waste glass was powdered, soaked in NaOH, then heated at 400 oC to obtain sodium silicate. Silica gels were produced by neutralized the sodium silicate using HCl, dissolved in H2O, and dried in an oven at 80 oC. Silica gels were solubilized in TBA, stirred, and dried in the oven to obtain C4-silica gels. Silica gels were characterized by X-ray Diffraction (XRD), while Infra Red (IR) and Scanning Electron Microscopy (SEM) analyses were conducted to obtained C4-silica gels. XRD analysis of silica gels showed that the highest peak intensity was observed at 2θ = 22.655°. The band at 1381.03 cm-1 in the IR spectrum was attributed to the nitro-oxygen bond (N-O). SEM images showed that the surface of C4-silica gels was smoother and more flat than the previous silica gels.

scholarly journals Optimization of the active component grinding process and hydrophobization of the obtained powder fire extinguisher

2021 ◽  
Vol 75 (2) ◽  
pp. 65-75
Author(s):  
Slavica Mihajlovic ◽  
Natasa Djordjevic ◽  
Marina Jovanovic ◽  
Milica Vlahovic ◽  
Ljubinko Savic ◽  
...  
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Ball Mill ◽  
Active Component ◽  
Grinding Process ◽  
Two Stage ◽  
Ceramic Ball ◽  
Fire Extinguishing ◽  
Stage Process ◽  
Grinding Time

This work presents a grinding process of monoammonium phosphate (MAP) as an active component in a powder fire extinguisher (PFE). The aim was to determine the grinding time for reaching the optimal particle size of MAP necessary for permanent fire extinguishing. MAP grinding was performed by using a laboratory ceramic ball mill and a vibrating cup mill. The grinding process was controlled by sieving using a 100 ?m sieve at precisely defined time intervals. The efficiency of a PFE depends on the share of the -100 ?m fraction of the active component, which has to exceed 60 %. The optimal grain size with 64 % of fraction of particle size -100 ?m was obtained after 33 min of grinding of ?3000 ?m mm grain size MAP by using a ball mill (single-stage grinding). In two-stage process, by grinding the same initial MAP sample (?3000 ?m) in the vibro mill for 10 min, powder with the upper limit grain size of 300 ?m and the mean grain diameter of 120 ?m was obtained. This sample with a reduced size was further ground in the ceramic ball mill yielding 67.5 % of the fraction of particle size -100 ?m after 19 min. The total time of the two-stage grinding process was 29 min. By analyzing the grinding time of MAP required to get the lowest required share of the fraction of particle size -100 ?m that provides the effectiveness of formed PFE it can be concluded that 64 % of this fraction was obtained after 33 min of single-stage grinding, while only after 26 min in the two-stage process. Thus, the grinding time was reduced by 7 min indicating certain energy savings. Stability and hydrophobicity of the obtained PFE were achieved by coating with magnesium stearate (MgSt) at the content of 2 % in a ball mill for 15 min. The coating was confirmed by the standardized procedure for verification of PFE hydrophobic properties in contact with water drops. To obtained PFE had component mass ratios of MAP:AS:CC:QS:MgSt=55:20:18:5:2 (AS-ammonium sulfate; CC-calcium carbonate, QS-quartz sand) and was further characterized by chemical and granulometric analyses. The fire extinguishing efficiency of the PFE was tested in controlled conditions, whereby fires were initiated by burning solid materials and flammable liquids. In both cases, immediate elimination of flames was achieved, thus proving the efficiency of the PFE obtained in this work for practical applications.

scholarly journals Studi Ekstraksi Bijih Emas Asal Pesawaran dengan Metode Pelindian Agitasi dalam Larutan Sianida

2020 ◽  
Vol 4 (2) ◽  
pp. 103
Author(s):  
La Ode Arham ◽  
Fika Rofiek Mufakhir ◽  
Hendra Saputra
Keyword(s):  
Grain Size ◽  
Chemical Analysis ◽  
Xrd Analysis ◽  
Gold Extraction ◽  
Gold Ore ◽  
Sieve Size ◽  
Mineral Phases ◽  
Ore Preparation ◽  
Wet Chemical ◽  
Ore Characterization

Research on the extraction of gold ore from Pesawaran, , Lampung, Indonesia, was carried out using the agitation leaching method in cyanide solution. This study aimed to obtain information on the use of conventional cyanidation methods for extracting gold from the Pesawaran gold ore. The ore preparation was carried out in the form of crushing, grinding and sieving to obtain samples with fraction sizes of -60 + 100 mesh, -100 +150 mesh, -150 + 200 mesh and -200 mesh. The ore characterization was performed using XRD, XRF, SEM-EDX, and wet chemical analysis. The XRD analysis showed that the main mineral phases were silica, hematite, aluminium hydroxide and orthoclase. The major constituents of the ore were Si (53,628%), Fe (15,996%), K (19,744%) and Al (8,045%). The Au content was determined by wet chemical analysis and was found to be 9.67 ppm. The experimental results show that the highest percentage of gold extraction of 83.33% was obtained using sodium cyanide at a concentration of 1000 ppm, a percent solids of 40% and a grain size of 200 mesh. Higher gold extraction was not achieved despite the use of a high cyanide concentration was probably because the remaining gold was not properly liberated. The results of SEM-EDX analysis showed that the gold grain size was <20 µm, while the grinding was performed only to a sieve size of -200 mesh (74 µm).

Improvement of Strength of Mg-12Gd-3Y-0.5Zr Alloys Processed by Combination of ECAP and Extrusion

2011 ◽  
Vol 682 ◽  
pp. 211-216
Author(s):  
Rong Zhu ◽  
Jin Qiang Liu ◽  
Jing Tao Wang ◽  
Ping Huang ◽  
Yan Jun Wu ◽  
...  
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Grain Boundary ◽  
Low Temperatures ◽  
Basal Slip ◽  
Extrusion Direction ◽  
Strengthening Mechanisms ◽  
Step Process ◽  
Angular Pressing ◽  
Peak Intensity

Equal channel angular pressing (ECAP) has been used to refine the grain size of Mg-12Gd-3Y-0.5Zr billet at about 400°C because it lacks sufficient ductility at low temperatures. However, <0001> peak intensity is oriented about 50º from the extrusion direction, which facilitates the basal slip, and decreases the yield strength. We have employed conventional extrusion at 300°C following ECAP to modify the texture in hard orientation. This two-step process makes use of two strengthening mechanisms a) grain boundary strengthening due to small grain size, and (b) texture strengthening due to grains in hard orientation. The samples processed by the two-step show the yield and ultimate strength to 283 and 308 MPa, respectively. Moreover, the activation of <c+a> slip and fine grains resulted from the ECAP helped to maintain a good ductility even after significant straining from conventional extrusion.

Study of a Novel Honeycomb Continuous Flocculator

2014 ◽  
Vol 1033-1034 ◽  
pp. 435-438
Author(s):  
Ming Dong ◽  
Qiong Fang Shao
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Flow Resistance ◽  
Separation Efficiency ◽  
Sewage Treatment ◽  
Internal Surface ◽  
Industrial Fermentation ◽  
Fermentation Liquid ◽  
Solid Liquid ◽  
Solid Liquid Separation

The continuous flocculator described in this article refers to a kind of continuous flocculation device designed to flocculate fermentation liquid. The honeycomb continuous flocculator is composed of a vessel and built-in trapezoid subassemblies, which divide the space within the vessel into multiple honeycomb channels. The length ratio between the longest diagonal of the regular hexagon and the axial length of the channel is within the range 0.01–0.04; and the internal surface roughness (Ra) of the channels should be 0 < Ra ≤ 0.2 μm. In contrast to current flocculator designs, the channels of the honeycomb continuous flocculator could control the floc grain size, grain fineness distribution in the fermentation liquid and flocculating time and decrease the flow resistance of the flocculating fermentation liquid and increase handling capacity. These capabilities improve solid-liquid separation efficiency for fermentation liquids. The flocculator could be used either for purification of industrial fermentation liquids or sewage treatment.

ATOMIC FORCE MICROSCOPY AND XRD ANALYSIS OF SILVER FILMS DEPOSITED BY THERMAL EVAPORATION

2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Characterization ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Grain Size ◽  
20 Nm

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.

Critical Laser Fluence Observed in (111) Texture, Grain Size and Mobility of Laser Crystallized Amorphous Silicon

1993 ◽  
Vol 297 ◽  
Author(s):  
R.I. Johnson ◽  
G.B. Anderson ◽  
J.B. Boyce ◽  
D.K. Fork ◽  
P. Mei ◽  
...  
Keyword(s):  
Grain Size ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Amorphous Silicon ◽  
Laser Fluence ◽  
Laser Energy ◽  
X Ray ◽  
Peak Intensity ◽  
Silicon Materials ◽  
The Relationship

This paper describes new results on the relationship between the grain size, mobility, and Si (111) x-ray peak intensity of laser crystallized amorphous silicon as a function of the laser fluence, shot density, substrate temperature, and film thickness. These observations include an unexpected narrow peak found in the silicon (111) x- ray peak intensity, which occurs at a specific laser fluence for a given film thickness and substrate temperature. Amorphous silicon materials processed at laser energy densities defined by this peak exhibit exceptionally large grain sizes and electron mobilities that cannot be obtained at any other energy and shot density combination above or below the energy at which the Si (111) x-ray peak intensity maximum occurs.

Pb(Zr0.52Ti0.48)O3 Ceramics Synthesized Using Planetary Ball Mill

2012 ◽  
Vol 620 ◽  
pp. 486-490
Author(s):  
Shafiza Afzan Sharif ◽  
Julie Juliewatty Mohamed ◽  
W.A.W. Yusoff
Keyword(s):  
Lead Zirconate Titanate ◽  
Ball Mill ◽  
Single Phase ◽  
Perovskite Phase ◽  
Xrd Analysis ◽  
Lead Zirconate ◽  
Planetary Ball Mill ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Pzt Ceramics

Lead zirconate titanate Pb (Zr0.52Ti0.48)O3, (PZT) ceramic was successfully prepared from the mixture of commercial PbO, TiO2and ZrO2powders using planetary ball mill at room temperature. The phase formation and microstructure of the milled powders were characterized using X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). XRD results indicated that the perovskite phase of PZT was formed from the mixture of starting materials after milling for 40 h. The grain sizes of the powders have been estimated from the SEM images to be ~200 nm. The compacted PZT samples were then sintered at 950 °C for 1 h. The samples were characterized by XRD and SEM, meanwhile the density was measured by Archimedes principle. XRD analysis on the sintered samples revealed the formation of single phase Pb (Zr0.52Ti0.48)O3ceramics while the SEM images estimated the grain size to be ~2 µm. The relative density of the obtained sintered PZT ceramics was measured to be approximately 99.93 % of the theoretical density. The results hence indicate that planetary ball mill is an effective preparatory technique to improve the sinterability of PZT ceramics.

Identification of Mixed-Layer Mineral of Cambodian Clays and their Phase Changes upon Firing

2012 ◽  
Vol 620 ◽  
pp. 72-76
Author(s):  
Bun Kim Ngun ◽  
Mohamad Hasmaliza ◽  
Kiyoshi Okada ◽  
Phat Bone ◽  
Zainal Arifin Ahmad
Keyword(s):  
Mixed Layer ◽  
Mineralogical Composition ◽  
Xrd Analysis ◽  
Phase Changes ◽  
Rational Analysis ◽  
Qualitative And Quantitative ◽  
Mineral Phases ◽  
Clay Deposits ◽  
Layer Mineral

Representative of clay deposits from central Cambodia were analyzed in terms of their mineral phases, mineralogical composition and phase changes after firing by qualitative and quantitative XRD analysis. To examine the phase changes, the samples were prepared and fired from 950 to 1200 °C. Results show that Cambodian clays contained quartz, illite, kaolinite, and chlorite-vermiculite mixed-layer as dominant mineral phases and the minor phases of albite and calcite also appeared in the samples. The rational analysis shows that chlorite-vermiculite was the main mineral in all Cambodian clays. After the samples were preceded upon firing, new phases of mullite, hematite and crystobalite were appeared above 1050 °C.

scholarly journals The investigation of electrical properties and microstructure of ZnO-doped Ba0.9Sr0.1TiO3 ceramics

2017 ◽  
Vol 07 (01) ◽  
pp. 1750007 ◽  
Author(s):  
Gang Liu ◽  
Wentao Jiang ◽  
Jingyong Jiao ◽  
Li Liu ◽  
Ziyang Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Solid State ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Electrical Breakdown Strength

Ba[Formula: see text]Sr[Formula: see text]TiO3 ceramics with or without ZnO have been prepared by traditional solid state reaction method. The XRD analysis showed that the doped Zn[Formula: see text] ions diffused into the BST crystal lattice, resulting in the variation of dielectric properties. Especially the dielectric constant at Curie point decreased with doping ZnO content when it is lower than 0.5[Formula: see text]mol%. Due to the promotion of sintering, doping ZnO can enhance the density of ceramics but increase grain size. However, ZnO is a kind of semiconductor and can lead to the decrease in electrical breakdown strength value.

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