scholarly journals Effect of Microwave Pretreatment on Grindability of Lead-Zinc Ore

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qing Yu ◽  
Dexin Ding ◽  
Wenguang Chen ◽  
Nan Hu ◽  
Lingling Wu ◽  
...  
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Particle Size Distribution ◽  
Microwave Irradiation ◽  
Size Distribution ◽  
Size Fraction ◽  
Milling Process ◽  
Total Energy Consumption ◽  
Microwave Pretreatment ◽  
Lead Zinc

The influence of microwave pretreatment on grindability of lead-zinc ore was studied through comparison analysis on the changes of particle size distribution, percentage of below 0.074 mm, energy consumption, and other indexes of grinding products before and after microwave pretreatment in the ball milling process. The results showed that the grindability of lead-zinc ore was improved obviously by microwave pretreatment. The particle size distribution curve of the grinding products was obviously higher than that of the samples without microwave irradiation. The yield of size fraction below 0.074 mm was also improved in a certain degree. Pulsed microwave irradiation was more effective than continuous microwave irradiation when other microwave parameters were consistent. The comprehensive energy consumption of lead-zinc ore pretreated by different microwave parameters was lower than that without microwave irradiation under the same grinding fineness. The total energy consumption was down by 30.1% when irradiated for 15 s at 7 kW power, and it was lower than that without microwave irradiated. The results showed that pulsed microwave pretreatment was more effective in reducing the comprehensive energy consumption of grinding process for lead-zinc ore. And water quenching after microwave irradiation can improve the grindability and reduce the energy consumption of grinding for lead-zinc ore.

scholarly journals Laser Diffraction as An Innovative Alternative to Standard Pipette Method for Determination of Soil Texture Classes in Central Europe

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1232
Author(s):  
Dušan Igaz ◽  
Elena Aydin ◽  
Miroslava Šinkovičová ◽  
Vladimír Šimanský ◽  
Andrej Tall ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Soil Texture ◽  
Polynomial Regression ◽  
Texture Classification ◽  
Size Fraction ◽  
Laser Diffraction ◽  
Classification Systems ◽  
Particle Size Fraction

The paper presents the comparison of soil particle size distribution determined by standard pipette method and laser diffraction. Based on the obtained results (542 soil samples from 271 sites located in the Nitra, Váh and Hron River basins), regression models were calculated to convert the results of the particle size distribution by laser diffraction to pipette method. Considering one of the most common soil texture classification systems used in Slovakia (according to Novák), the emphasis was placed on the determination accuracy of particle size fraction <0.01 mm. Analysette22 MicroTec plus and Mastersizer2000 devices were used for laser diffraction. Polynomial regression model resulted in the best approximation of measurements by laser diffraction to values obtained by pipette method. In the case of particle size fraction <0.01 mm, the differences between the measured values by pipette method and both laser analyzers ranged in average from 3% up to 9% and from 2% up to 11% in the case of Analysette22 and Mastersizer2000, respectively. After correction, the differences decreased to average 3.28% (Analysette22) and 2.24% (Mastersizer2000) in comparison with pipette method. After recalculation of the data, laser diffraction can be used alongside the sedimentation methods.

scholarly journals Control of the size and compositional distributions in a milling process by using a reverse breakage matrix approach

2021 ◽  
pp. 4-4
Author(s):  
Nemanja Bojanic ◽  
Aleksandar Fistes ◽  
Tatjana Dosenovic ◽  
Aleksandar Takaci ◽  
Mirjana Brdar ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Milling Process ◽  
Matrix Approach ◽  
Flour Milling ◽  
Input And Output ◽  
Input Material ◽  
Compositional Distribution ◽  
Wheat Flour Milling

A method based on the reverse breakage matrix approach is proposed for controlling the effects that milling has on the particle size distribution and composition of the comminuted material. Applicability, possibilities, and limitations of the proposed method are tested on examples related to the process of wheat flour milling. It has been shown that the reverse matrix approach can be successfully used for defining the particle size distribution of the input material leading to the desired, predetermined particle size and compositional distribution in the output material. Moreover, we have illustrated that it is possible to simultaneously control both, input and output particle size distribution, together with the composition of the output material.

scholarly journals Influence of grinding method and grinding intensity of corn on mill energy consumption and pellet quality

2016 ◽  
Vol 70 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Djuro Vukmirovic ◽  
Jovanka Levic ◽  
Aleksandar Fistes ◽  
Radmilo Colovic ◽  
Tea Brlek ◽  
...  
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Hammer Mill ◽  
Pellet Quality ◽  
Roller Mill ◽  
Grinding Method

In recent years there is an emerging trend of coarse grinding of cereals in production of poultry feed due to positive influence of coarse particles on poultry digestive system. Influence of grinding method (hammer mill vs. roller mill) and grinding intensity of corn (coarseness of grinding) on mill specific energy consumption and pellet quality was investigated. By decreasing grinding intensity of corn (coarser grinding), specific energy consumption of both hammer mill and roller mill was significantly decreased (p < 0.05). When comparing similar grinding intensities on hammer mill and roller mill (similar geometric mean diameter or similar particle size distribution), specific energy consumption was higher for the hammer mill. Pellet quality decreased with coarser grinding on hammer mill but, however, this effect was not observed for the roller mill. Generally, pellet quality was better when roller mill was used. It can be concluded that significant energy savings could be achieved by coarser grinding of corn before pelleting and by using roller mill instead of hammer mill. From the aspect of pellet quality, if coarser grinding is applied it is better to use roller mill, concerning that more uniform particle size distribution of corn ground on roller mill probably results in more uniform particle size distribution in pellets and this provides better pellet quality.

scholarly journals Experimental Uncertainty Analysis for the Particle Size Distribution for Better Understanding of Batch Grinding Process

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 862
Author(s):  
José Delgado ◽  
Freddy A. Lucay ◽  
Felipe D. Sepúlveda
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Milling Process ◽  
Design Parameters ◽  
Grinding Process ◽  
Distribution Models ◽  
Statistical Parameters ◽  
Weight Percentage ◽  
Do So

Uncertainty in industrial processes is very common, but it is particularly high in the grinding process (GP), due to the set of interacting operating/design parameters. This uncertainty can be evaluated in different ways, but, without a doubt, one of the most important parameters that characterise all GPs is the particle size distribution (PSD). However, is the PSD a good way to quantify the uncertainty in the milling process? This is the question we attempt to answer in this paper. To do so, we use 10 experimental grinding repetitions, 3 grinding times, and 14 Tyler meshes (more than 400 experimental results). The most relevant results were compared for the weight percentage for each size (WPES), cumulative weight undersize (CWU), or the use of particle size distribution models (PSDM), in terms of continuous changes in statistical parameters in WPES for different grinding times. The probability distribution was found to be changeable when reporting the results of WPES/CWU/PSDM, we detected the over-/under-estimation of uncertainty when using WPES/CWU, and variations in the relationships between sizes were observed when using WPES/CWU. Finally, our conclusion was that the way in which the data are analysed is not trivial, due to the possible deviations that may occur in the uncertainty process.

scholarly journals Influence of the Feed Moisture, Rotor Speed, and Blades Gap on the Performances of a Biomass Pulverization Technology

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Siyi Luo ◽  
Yangmin Zhou ◽  
Chuijie Yi ◽  
Yin Luo ◽  
Jie Fu
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Specific Energy ◽  
Rotor Speed ◽  
Operational Parameters ◽  
Product Particle ◽  
Dry Conditions ◽  
Feed Moisture

Recently, a novel biomass pulverization technology was proposed by our group. In this paper, further detailed studies of this technology were carried out. The effects of feed moisture and crusher operational parameters (rotor speed and blades gap) on product particle size distribution and energy consumption were investigated. The results showed that higher rotor speed and smaller blades gap could improve the hit probability between blades and materials and enhance the impacting and grinding effects to generate finer products, however, resulting in the increase of energy consumption. Under dry conditions finer particles were much more easily achieved, and there was a tendency for the specific energy to increase with increasing feed moisture. Therefore, it is necessary for the raw biomass material to be dried before pulverization.

scholarly journals Particle Size Distribution of the Coal Bottom Ash from the Large Combustion Plant

2015 ◽  
Vol 13 ◽  
pp. 210-215 ◽  
Author(s):  
Olimpia Ghermec ◽  
Ionela Gabriela Bucse ◽  
Mariana Ciobanu
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Bottom Ash ◽  
Size Fraction ◽  
Steam Boiler ◽  
Major Fraction ◽  
Coal Bottom Ash ◽  
Particle Size Analyzer ◽  
Reduce Emissions

Human existence is dependent on the consumption of electricity and of thermal energy. One of the environmental problems is represented by the particulate matter with the diameter of less than 2.5 mm derived from combustion of coal. In order to find solutions to reduce emissions at source, the particle size distribution of the coal bottom ash after removing it from the steam boiler of the large combustion plant from Romag Halanga in Drobeta Turnu – Severin area was determined. Dry particle size distribution shows that the major fraction is one that has a particle size of 125 μm. Particle size distribution in the smallest size fraction was performed with laser diffraction particle size analyzer Brookhaven 90 Plus Nanoparticle Size Analyzer. Particle size distribution shows that in the composition of the coal bottom ash were found particles with nanometric dimensions.

scholarly journals Development and Validation of an Online Analyzer for Particle Size Distribution in Conveyor Belts

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 581
Author(s):  
Claudio Leiva ◽  
Claudio Acuña ◽  
Diego Castillo
Keyword(s):  
Image Processing ◽  
Particle Size ◽  
Energy Consumption ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Large Particle ◽  
Equivalent Diameter ◽  
Online Measurement ◽  
Particle Detection ◽  
Detection Algorithms

Online measurement of particle size distribution in the crushing process is critical to reduce particle obstruction and to reduce energy consumption. Nevertheless, commercial systems to determine size distribution do not accurately identify large particles (20–250 mm), leading to particle obstruction, increasing energy consumption, and reducing equipment availability. To solve this problem, an online sensor prototype was designed, implemented, and validated in a copper ore plant. The sensor is based on 2D images and specific detection algorithms. The system consists of a camera (1024p) mounted on the conveyor belt and image processing software, which improves the detection of large particle edges. The algorithms determine the geometry of each particle, from a sequence of digital photographs. For the development of the software, noise reduction algorithms were evaluated and selected, and a routine was designed to incorporate morphological mathematics (erosion, dilation, opening, lock) and segmentation algorithms (Roberts, Prewitt, Sobel, Laplacian–Gaussian, Canny, watershed, geodesic transform). The software was implemented (in MatLab Image Processing Toolbox) based on the 3D equivalent diameter (using major and minor axes, assuming an oblate spheroid). The size distribution adjusted to the Rosin Rammler function in the major axis. To test the sensor capabilities, laboratory images were used, where the results show a precision of 5% in Rosin Rambler model fitting. To validate the large particle detection algorithms, a pilot test was implemented in a large mining company in Chile. The accuracy of large particle detection was 60% to 67% depending on the crushing stage. In conclusion, it is shown that the prototype and software allow online measurement of large particle sizes, which provides useful information for screening equipment maintenance and control of crushers’ open size setting, reducing the obstruction risk and increasing operational availability.

scholarly journals Aspects regarding particle size distribution and energy consumption when grinding husked rice seeds

2020 ◽  
Author(s):  
Gheorghe Voicu ◽  
Gabriel-Alexandru Constantin ◽  
Elena-Madalina Stefan ◽  
Paula Tudor ◽  
Mariana Gabriela Munteanu
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Rice Seeds

An alternative method for determining particle-size distribution of forest road aggregate and soil with large-sized particles

2014 ◽  
Vol 44 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Hakjun Rhee ◽  
Randy B. Foltz ◽  
James L. Fridley ◽  
Finn Krogstad ◽  
Deborah S. Page-Dumroese
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Size Fraction ◽  
Forest Road ◽  
State Highway ◽  
American Society ◽  
Northern Idaho ◽  
Aggregate Material ◽  
Laboratory Time

Measurement of particle-size distribution (PSD) of soil with large-sized particles (e.g., 25.4 mm diameter) requires a large sample and numerous particle-size analyses (PSAs). A new method is needed that would reduce time, effort, and cost for PSAs of the soil and aggregate material with large-sized particles. We evaluated a nested method for sampling and PSA by comparing it with the methods that follow the American Association of State Highway and Transportation Officials (AASHTO) standard T88-00 and the American Society for Testing and Materials (ASTM) standard D422-63. Using 33 forest road aggregate samples from the Clearwater National Forest in northern Idaho, the nested method required much less laboratory time and effort and resulted in similar PSA values, except for the 0.149 mm (No. 100) sieve, where the smallest particle-size fraction (PSF) values (1.30% and 1.39%) were observed. The nested method shows great potential for determining PSDs of the soil and aggregate material with large-sized particles and should be tested on other forest soils and road aggregates. The nested sampling and analysis method allows for the same number of samples to be collected but requires less laboratory time, making it more efficient and economical for testing the soil and aggregate material with large-sized particles such as forest road aggregate.

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