scholarly journals Experimental Study on the Characteristics of Ultrafine Grinding of Potassium-bearing Shale and the Feasibility of Roasting Pre-cracking

2021 ◽  
Author(s):  
Zaisheng Zhu ◽  
Zhenquan He ◽  
Guosheng Gai
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Industrial Applications ◽  
Microwave Pretreatment ◽  
Ultrafine Grinding ◽  
Potential Alternative

Abstract As potassium-bearing shale is still being developed as a potential alternative to potash, the first step to improve its utilisation is to reduce its particle size. This paper explores whether roasting pre-cracked potassium-bearing shale can improve the quality of ultra-fine crushing products. By analysing the particle size distribution and the fractal dimension of the particle size distribution, the results for 1 h and 2 h roasting pre-cracking experiments were found to be contradictory. AHP-fuzzy comprehensive evaluation of the three indicators of product quality and quantity was used, resulting in a unique indicator. Roasting pre-cracking for 2 h was found to have a facilitating effect, with the average of the three fuzzy comprehensive evaluation values increasing from 0.71 to 0.78. The great difference in cost outlay suggests that the technique is not suitable for industrial applications. Subsequently, two groups of microwave pretreatment experiments were carried out but led to unsatisfactory results in which microwave pretreatment was not conducive to the ultrafine grinding of potassium-bearing shale.

scholarly journals Characteristics of ultrafine-ground potassium-bearing shale and the effects of roasting pre-cracking

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Zaisheng Zhu ◽  
Zhenquan He ◽  
Guosheng Gai
Keyword(s):  
Particle Size ◽  
Fractal Dimension ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Product Analysis ◽  
Mean Values ◽  
Analytic Hierarchical Process ◽  
The Cost

AbstractPotassium-bearing shale is being developed as a potential alternative to potash for use in fertilisers. The first step in this process is to reduce its particle size by crushing. This paper explores whether roasting pre-cracked potassium-bearing shale can improve the quality of the resulting ultrafine product. Analysis of the particle size distribution of the ultrafine product and its fractal dimension found contradictory results: the minimum particle size distribution was obtained by roasting for 2.5 h, while the minimum fractal dimension was obtained by roasting for 1 h. Fuzzy comprehensive evaluation was conducted with three indicators—(1) the weight of the − 10 μm product, (2) the fractal dimension of the particle size distribution, and (3) d97—to obtain a unique combination of indicators that reflects the quality and quantity of the products. The weights of the three indicators were calculated by an analytic hierarchical process to be 0.69, 0.149 and 0.161, respectively. Roasting pre-cracked shale for 2–2.5 h was found to improve the mean values of the fuzzy comprehensive evaluation indicators by about 0.07. However, the cost increased from 2.82 RMB to ≥ 10.08 RMB, which is not feasible for widespread industrial implementation.

The Quality of U100 Sampling

1986 ◽  
Vol 2 (1) ◽  
pp. 419-423
Author(s):  
I. L. Whyte
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
General Purpose ◽  
Volume Changes ◽  
Sample Quality ◽  
Class 1 ◽  
Sample Disturbance

AbstractThe origins and development of the U100 (U4) thick-walled open-drive sampler are reviewed. The requirements of CP 2001 and BS 5930 are examined in relation to sample quality, and these are shown to be too favourable. Causes of sample disturbance are considered, particularly those due to volume changes, and shown to depend on moisture content, plasticity and particle size distribution. Quality classes possible with conventional U100 samples are suggested, and Classes 3 or 4 are to be generally expected. Class 1 samples are improbable. It is recommended that a general purpose sampler such as the U100 should have a maximum inside clearance of 1% and not ‘about 1%’ as recommended in BS 5930.

Effect of the particulate morphology of resin on the gelation process of PVC plastisols

2017 ◽  
Vol 37 (8) ◽  
pp. 757-764 ◽  
Author(s):  
Yubi Ji ◽  
Zhao Yang ◽  
Min Shi ◽  
Hong Tan
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Key Factors ◽  
Factors Affecting ◽  
Gelation Process ◽  
Secondary Particles ◽  
Poly Vinyl Chloride ◽  
Opposite Behavior

Abstract The gelation process of poly(vinyl chloride) (PVC) plastisol is very important to ensure the quality of the product and is affected by the type of resins, plasticizers, and other additives. In this study, the gelation process of the as-prepared PVC plastisol was characterized by measuring the evolution of vibrational viscosity with temperature or time using a vibrational viscometer. Furthermore, the effect of some commercial resins with different particulate morphologies on the gelation process was investigated by synchronously combining scanning election microscopy and laser particle size analyses. The results of this study proved that the particle size distribution and the aggregation degree of the secondary particles of a resin are the key factors affecting the gelation process. For the resin with bimodal particle size distribution, the closer the aggregation of the secondary particles, the slower the gel speed; however, an opposite behavior was observed for the resins with unimodal particle size distribution.

scholarly journals Risiko des Eintrags von Phosphor in den Hallwilersee durch Bodenerosion

2015 ◽  
Vol 70 (3) ◽  
pp. 193-198 ◽  
Author(s):  
S. Müller ◽  
D. Schaub
Keyword(s):  
Particle Size ◽  
Soil Erosion ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Surface Waters ◽  
Aggregate Stability ◽  
Eutrophic Lake ◽  
Soil Samples

Abstract. An important factor in the release of phosphorus by soil erosion, with corresponding consequences on the quality of surface waters, is the formation of aggregates and their stability. Around the eutrophic Lake Hallwil six arable lands were examined in five repetitions regarding aggregate and particle size distribution, P-contents of the different fractions and aggregate stability. Central to this was the use of the setting column for fractionation of soil samples. In the case of Lake Hallwil the risk of phosphorus discharges by soil erosion seems low since the phosphorus is mainly bound in aggregates which are transported over short distances only. Thus other pathways (runoff from grassland, leaching via drains) may be more important.

Анализ параметров медицинского технологического оборудования, учитывающие факторы, влияющие на качество изготовления лекарств

2020 ◽  
pp. 90-95
Author(s):  
T.V. Karlova ◽  
◽  
D.O. Sv ◽  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Shape ◽  
Particle Surface ◽  
Technological Equipment ◽  
Factors Affecting ◽  
Particle Strength ◽  
The Web

The article is devoted to the analysis of parameters of medical technological equipment that take into account factors affecting the quality of manufacture of drugs. Factors such as particle size, particle size distribution, particle shape, particle surface properties, particle strength, which, based on the «Web» method, are used to analyze the «vibrosieve» technological equipment, are considered.

Effect of Particle Size Distribution and Selective Alcohol Additives for Preparation of High Concentration Coal-Water Slurry

2020 ◽  
Vol 12 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Debadutta Das ◽  
Anupama Routray ◽  
Swetashree Pattanaik ◽  
Pankaj K. Parhi ◽  
Bijnyan R. Das ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Static Stability ◽  
Industrial Applications ◽  
High Concentration ◽  
Oh Groups ◽  
Water Slurry ◽  
Coal Water Slurry ◽  
Water Alcohol

Background: The alternative of oil is highly essential in the present context due to the acute shortage of oil as well as increasing demand for it from different public and private sectors. Since 1980, attention has been focused on coal-water slurry as an alternative fuel for the power generation industry and a suitable substitute for oil in several industrial applications. One of the exciting areas in Coal Water Slurry (CWS) is coal–water-alcohol slurry in which different alcohol compound can act as a dispersant for the stabilisation of coal–water slurry. Objective: The objective of this paper is to prepare a high concentration coal–water-alcohol slurry using glycerol, glycol and ethanol as an additive, and different particle size distribution of coal. This will increase the surface activity of the coal thereby, decreasing the viscosity of the slurry. Method: Two bimodal samples are prepared in which coarse particles are (212 μm - 300 μm), (150 μm – 212 μm) and fine particle below 75 μm. Three types of alcohol additive namely glycerol, glycol and ethanol are used as a dispersant. Malvern Particle size analyzer is used to measure the particle size distribution of the coal samples. Rheological study of CWAS was conducted using HAAKE RHEO STRESS 1. Result: From the experiment, it has been concluded that the optimum addition of glycerol in water is taken as 90:10 of water and glycerol ratio because after that, there is no further decrease in the value of viscosity. An optimum value of glycol and ethanol mixed in water was determined and found as in the ratio of 86:14 and 82:18, respectively. Conclusion: From different parameter studies like coal concentration, pH, temperature, apparent viscosity and stability, it has been concluded that coal-water-glycerol slurry is better than other coal water- alcohol slurry. This is because of the presence of more OH- groups in glycerol. The static stability of this coal-water-alcohol slurry exists for the maximum period of 31 days.

Size Distributions of Particles Extracted from Different Materials Compared with the MIL-STD-1246 Particle Size Distribution

2000 ◽  
Vol 43 (4) ◽  
pp. 25-29
Author(s):  
Roger Welker
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Geometric Mean ◽  
Industrial Applications ◽  
Distribution Analysis ◽  
Size Distributions ◽  
Naturally Occurring ◽  
History Of ◽  
Log Normal

MIL-STD-1246 particle-size distribution is the basis for specifying the particle cleanliness of surfaces for many governmental and industrial applications. MIL-STD-1246 states that naturally occurring particle contamination on surfaces follows a log-normal particle-size distribution, with a geometric mean of 1 μm, following a very precise size specification. However, the naturally occurring particle-size distribution may be a function of the material under examination or the prior cleaning or surface treatment history of the material. This paper explores the relation between the MIL-STD-1246 particle-size distribution and particle-size distributions measured after extraction followed by liquidborne particle-size distribution analysis.

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