scholarly journals Mechanochemical Treatment to Remove Arsenic from Copper Ore

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 349
Author(s):  
Shingo Ishihara ◽  
Kozo Shinoda ◽  
Junya Kano
Keyword(s):  
Arsenic Removal ◽  
Chemical Activation ◽  
Xrd Analysis ◽  
Mechanochemical Treatment ◽  
Copper Ore ◽  
Wet Grinding ◽  
Dry Grinding ◽  
Grinding Conditions ◽  
Diffraction Peaks ◽  
Comparison Of The Results

This study tested the removal of arsenic from copper ore concentrate via a mechanochemical treatment by planetary ball milling. The harmful components of ore, such as arsenic, are increasing year by year and decreasing the copper grade, therefore there is a strong need to improve the separation of arsenic from copper ore. The effect of grinding as a result of chemical activation caused by mechanochemical treatment was evaluated by XRD and X-ray absorption spectroscopy (XAS) measurements. From the results of the XRD analysis, several crystalline minerals were identified from the original samples. The diffraction peaks of the original samples were reduced by grinding, although grinding did not generate any new diffraction peaks. The comparison of the results of grinding in dry and wet conditions showed that the rate of disappearance of the crystalline minerals was faster in dry grinding than in wet grinding. To clarify the chemical state of arsenic in copper ore, XAS analysis was carried out. The results indicated that the arsenic compound changed from sulfide, in the original sample, to oxide after grinding. As a result of oxidation, the arsenic was easy to dissolve in a water and alkaline solution, and optimized dry and wet grinding conditions achieved up to 76% arsenic removal efficiency.

scholarly journals Optimization of Wet Grinding Conditions of Sheets Made of Stainless Steel

2020 ◽  
Vol 4 (4) ◽  
pp. 114
Author(s):  
Akira Mizobuchi ◽  
Atsuyoshi Tashima
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Rotational Speed ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Steel Sheets ◽  
Wet Grinding ◽  
Grinding Fluid ◽  
Dry Grinding ◽  
Grinding Conditions

This study addresses the wet grinding of large stainless steel sheets, because it is difficult to subject them to dry grinding. Because stainless steel has a low thermal conductivity and a high coefficient of thermal expansion, it easily causes grinding burn and thermal deformation while dry grinding on the wheel without applying a cooling effect. Therefore, wet grinding is a better alternative. In this study, we made several types of grinding wheels, performed the wet grinding of stainless steel sheets, and identified the wheels most suitable for the process. As such, this study developed a special accessory that could be attached to a wet grinding workpiece. The attachment can maintain constant pressure, rotational speed, and supply grinding fluid during work. A set of experiments was conducted to see how some grinding wheels subjected to some grinding conditions affected the surface roughness of a workpiece made of a stainless steel sheet (SUS 304, according to Japanese Industrial Standards: JIS). It was found that the roughness of the sheet could be minimized when a polyvinyl alcohol (PVA) grinding wheel was used as the grinding wheel and tap water was used as the grinding fluid at an attachment pressure of 0.2 MPa and a rotational speed of 150 rpm. It was shown that a surface roughness of up to 0.3 μm in terms of the arithmetic average height could be achieved if the above conditions were satisfied during wet grinding. The final surface roughness was 0.03 μm after finish polishing by buffing. Since the wet grinding of steel has yet to be studied in detail, this article will serve as a valuable reference.

scholarly journals Experimental Study on Grinding Force of Zirconia Ceramics in Dry/Wet Grinding Environment

2018 ◽  
Vol 198 ◽  
pp. 02004
Author(s):  
Junping Zhang ◽  
Weidong Wang ◽  
Songhua Li ◽  
Han Tao
Keyword(s):  
Grinding Force ◽  
Grinding Wheel ◽  
Feed Speed ◽  
Zirconia Ceramics ◽  
Grinding Forces ◽  
Measuring Device ◽  
Linear Speed ◽  
Wet Grinding ◽  
Dry Grinding ◽  
Force Ratio

The impacts of different linear speed of grinding wheel, grinding depth and workpiece feed speed with or without grinding fluid on grinding force were studied by plane grinding machining of zirconia ceramics. The impacts of different machining environment and grinding parameter on normal and tangential grinding forceswere studied by testing the grinding force during grinding with a force measuring device. The studies showed that the normal and tangential grinding forces decrease with the increase of the linear speed of grinding wheel and increase with the improvement of grinding depth and workpiece feed speed. The grinding depth has the greatest impacts on the normal and tangential grinding forces in dry grinding environment; while in wet grinding environment, the grinding depth exerts the greatest impacts on the normal grinding force and the linear speed of grinding wheel imposes the greatest impacts on the tangential grinding force. In addition, it was found that the normal grinding force in dry grinding is minor than that in wet grinding, that the tangential grinding force in dry grinding is greater than that in wet grinding, and that the grinding force ratio in dry grinding is lower than that in wet grinding.

Mechanochemical Polymorphic Transformation of Photocatalyst Material TiO2 and its Dependence on the Milling Operation

2011 ◽  
Vol 675-677 ◽  
pp. 283-286
Author(s):  
Guo Min Mi ◽  
Fumio Saito
Keyword(s):  
Phase Transformation ◽  
Titanium Dioxide ◽  
Polymorphic Transformation ◽  
Metastable Phase ◽  
Planetary Mill ◽  
Wet Grinding ◽  
Dry Grinding ◽  
Milling Operation ◽  
Lower Temperature ◽  
Tumbling Mill

Some dry and wet grinding experiments have been respectively conducted on titanium dioxide which is a noble photocatalyst material in a mortar, a tumbling mill and a planetary mill. Anatase is apt to transform to rutile via a metastable phase brookite in every kind of mills in the case of dry grinding. And it hardly takes place for phase transformation from rutile to other forms. It is shown that the kind of mill has not decisive effect on the mechanochemical polymorphic transformation of titanium dioxide, which merely influences the rate of phase transformation. On the other hand, the addition of other liquid media, such as water and acetone, is helpless for phase transformation of anatase. Only anatase can transform to metastable phase brookite by wet grinding. When ground titanium dioxide is heated, the amorphous phase is easier to transform to rutile than metastable phase brookite at lower temperature.

Influence of Carbon Concentration as Coating on Electrical Conductivity of LiFeSi0.03P0.97O4/C

2021 ◽  
Vol 1028 ◽  
pp. 185-190
Author(s):  
Hafizhah Ellora Della ◽  
Mochamad Zainuri ◽  
Pelangi Az Zahra ◽  
Puri Olyvia Swastika ◽  
Triwikantoro
Keyword(s):  
Electrical Conductivity ◽  
Carbon Concentration ◽  
Research Study ◽  
Raw Materials ◽  
Carbon Sources ◽  
Xrd Analysis ◽  
Si Doping ◽  
Diffraction Peaks ◽  
Materials Used ◽  
Carbon Concentrations

This research study about the influence of carbon concenttration as coating on electrical conductivity of LiFeSi0.03P0.97O4/C. Synthesis of LiFeSi0.03P0.97O4/C was carried out different carbon concentrations of 7, 9, and 11 wt%. The raw materials used are Fe2O3, Li2CO3, (NH4)2HPO4, SiO2 as ion Si doping, and glucose as carbon sources. The XRD analysis results showed that all the diffraction peaks in samples were the olivine LiFePO4 phase. From the EIS result, Samples with the addition carbon concentration of 9 wt% produce the highest electrical conductivity values of 4.18 x 10-7 S/cm.

The effect of grinding conditions on the flotation of a sulphide copper ore

2003 ◽  
Vol 16 (11) ◽  
pp. 1213-1216 ◽  
Author(s):  
K.L.C. Gonçalves ◽  
V.L.L. Andrade ◽  
A.E.C. Peres
Keyword(s):  
Copper Ore ◽  
Grinding Conditions

Influence of particle size on copper recovery from sulfide ore by the moderately thermophilic microorganisms

2019 ◽  
Vol 116 (1) ◽  
pp. 119
Author(s):  
Wen-bo Zhou ◽  
Kai Li ◽  
Yu-guang Wang ◽  
Li-juan Zhang ◽  
Hai-na Cheng ◽  
...  
Keyword(s):  
Particle Size ◽  
Xrd Analysis ◽  
Microbial Interactions ◽  
Copper Recovery ◽  
Mineral Particle ◽  
Copper Ore ◽  
Thermophilic Microorganisms ◽  
Moderately Thermophilic ◽  
Before And After ◽  
Leaching Condition

The bioleaching of copper ore by the defined moderately thermophilic consortium containing Leptospirillum ferriphilum and Acidithiobacillus caldus was carried out in the bench-scale column. Bioleaching experiments showed that the leaching rate was 25% higher than that of a conventional leaching and the acid consumption was reduced by 33% at the optimal leaching condition. Meanwhile, the effect of different particle sizes on the rate of the copper leaching was also investigated, and it was shown that the particle size affects the bioleaching rate significantly in the range of 5–25 mm, in which approximately 89.27% of copper was extracted at 5–10 mm, while only 57.08% at 15–25 mm. The results obtained by X-ray diffraction (XRD) analysis of the mineral samples before and after microbial and chemical leaching revealed that the decrease in particle size of the minerals resulted in an enhancement of complex microbial interactions. Especially for the particle size of 5–10 mm, a significant amount of elemental sulfur and jarosite formed on the surface of the mineral, while it was further confirmed that critical microbe-mineral interactions have taken place on the mineral surface. The results indicated that mineral particle size is an integral factor to improve the copper recovery from ore in heap leaching operation. This will provide a reference to the heap construction for the bioleaching.

Effect of Isostatic GAS Pressure on Optical Quality of MgAl2O4 Spinel

1991 ◽  
Vol 251 ◽  
Author(s):  
S.E. Hsu ◽  
C.T. Wang ◽  
D.S. Tsai ◽  
S.J. Yang
Keyword(s):  
Applied Pressure ◽  
Xrd Analysis ◽  
Optical Quality ◽  
Gas Pressure ◽  
Pressure Treatment ◽  
Before And After ◽  
Diffraction Peaks ◽  
Bimodal Grain Size ◽  
Hip Process

ABSTRACTOptical transparent MgAl2O4 spinel is obtained by processing with high gas pressure to eliminate or reduce the residual pores. Both hot–pressed and sintered specimens are post–treated by the high argon hipping process here. The densities of all the specimens before hipping are over 99% theoretical density. In the high gas pressure process, the pressure ranges from 2000 to 30000psi at 1500°C for 2hrs. The transmittance from visible to IR are measured before and after gas pressure treatment. The transparency from visible to IR increases significantly with the HIP process. When applied pressure less than 6000psi, bulk density is proportional to the logarithm of the pressure and the logarithm of the absorption coefficient is proportional to the porosity. Bimodal grain–size distribution exists in the sintered and hipped specimens but is not observed in the uniaxial–hot–pressed–only samples. XRD analysis indicates the width of the diffraction peaks in the HIP specimens is less than that in UAHP specimens. The result illustrates the HIP process improves the spinel crystallinity.

Research and Analysis of Dry Crushed Waste Tire Processing

2011 ◽  
Vol 109 ◽  
pp. 228-231 ◽  
Author(s):  
Jia Yang ◽  
Song Ge Yang ◽  
Li Jun Qiu
Keyword(s):  
Particle Size ◽  
Powder Particle Size ◽  
Main Mode ◽  
Waste Tires ◽  
Waste Tire ◽  
Powder Production ◽  
Wet Grinding ◽  
Grinding Method ◽  
Cryogenic Grinding ◽  
Dry Grinding

For the treatment of waste tires and waste tire reuse has become an important task in today's society. Waste tire processing methods are: restructuring the use of the prototype. Energy use of waste tires as fuel will use high-temperature heating with thermal decomposition of waste tires, to promote its decomposition into oil, combustible gas, carbon. Scrap tire retreading. Powder production and other means. By mechanical means will be used after the tire tread and some other parts of the split will be obtained after crushing the powder material is powder. Currently the main mode of production has powder dry grinding, cryogenic grinding and wet grinding method. Different methods produce different particle size range of powder, powder surface morphology is also different. Dry grinding, wet grinding and cryogenic grinding of the legal system into a powder particle size in the range of 0.3 mm ~ 1.5 mm, 0.075 mm ~ 0.3 mm and 0.075 mm or less. Dry grinding method because of his production and processing simple process has been widely used in powder production process. For dry grinding process and mechanical work made for the research and analysis.

A Study on the Grinding Temperature Field for Titanium Alloy

2007 ◽  
Vol 339 ◽  
pp. 45-49
Author(s):  
W. Li ◽  
Tong Xing ◽  
Bao Xiang Qiu ◽  
Gang Xiang Hu ◽  
Yang Fu Jin
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Heat Source ◽  
Simulation Software ◽  
Transient Temperature ◽  
Fe Model ◽  
Grinding Temperature ◽  
Wet Grinding ◽  
Dry Grinding ◽  
Grinding Temperature Field

A reasonable finite element (FE) model of grinding temperature field has been developed on the basis of analysis of the transient temperature field， and three kinds of boundary conditions are loaded on the element of a moving heat source. The study, which is based on the finite element principle, has been carried out using the numerical simulation software ANSYS. Many results have been obtained including three dimensional temperature distribution map. The simulated results under different conditions show good agreement with the experimental results. With the comparison of the dry-grinding and wet-grinding, the result shows that the wet-grinding temperature with a proper grinding fluid is rather lower than the dry-grinding temperature. Finally, the variable coefficient of convective heat transfer and the different form heat source have been discussed in detail.

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