scholarly journals The Effect of the Characteristics of the Partition Plate Unit on the Separating Process of −6 mm Fine Coal in the Compound Dry Separator

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 215 ◽  
Author(s):  
Chen ◽  
Wang ◽  
Luo ◽  
Zhao ◽  
Lv ◽  
...  
Keyword(s):  
Density Distribution ◽  
Size Fraction ◽  
Industrial Applications ◽  
Average Density ◽  
Ash Content ◽  
Separation Process ◽  
Contour Map ◽  
Separation Technology ◽  
Fine Coal ◽  
Separation Results

Although compound dry separation technology has been applied to industrial applications for +6 mm size fraction of coal separation, the technology has not been widely applied in the separation of fine coal (−6 mm). In this study, the effect of the partition plate unit characteristics on both the average density of particles in the bed uniformly and the final separation results in a fine coal separation process were studied. According to the results, the standard deviations of the corresponding density distribution were 0.08, 0.14, and 0.07 when the height of the partition plate was 2.5 cm, the partition plate angle was 35°, and the distance from the apex of partition plate on the backplane, was 12 cm, respectively, which were the lowest values at the same level. These results showed that the average density of particles in the bed was uniformly, and its corresponding density distribution contour map was more regular. When the amplitude was 2.8 mm, the frequency was 29 Hz, the height of the partition plate was 2.5 cm, the partition plate angle was 35°, and the distance from the apex of the partition plate to the backplane was 12 cm; as a result, the E value was 0.115 g/cm3, the yield of the concentrate was 69.24%, the ash content was 12.52%, and the separation effect was better. The characteristics of the partition plate unit have an important effect on the separating process of −6 mm fine coal in the compound dry separator.

scholarly journals Configuration of flowsheet and reagent dosage for gilsonite flotation towards the ultra-low-ash concentrate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ataallah Bahrami ◽  
Fatemeh Kazemi ◽  
Mirsaleh Mirmohammadi ◽  
Yousef Ghorbani ◽  
Saghar Farajzadeh
Keyword(s):  
Sulfuric Acid ◽  
Sodium Silicate ◽  
Tannic Acid ◽  
Size Fraction ◽  
Sodium Cyanide ◽  
Ash Content ◽  
Drilling Fluids ◽  
Gas Oil ◽  
Size Fractions ◽  
Process Mineralogy

AbstractGilsonite has a wide variety of applications in the industry, including the manufacture of electrodes, paints and resins, as well as the production of asphalt and roof-waterproofing material. Gilsonite ash is a determining parameter for its application in some industries (e.g., gilsonite with ash content < 5% used as an additive in drilling fluids, resins). Due to the shortage of high grade (low ash) gilsonite reserves, the aim of this study is to develop a processing flowsheet for the production of ultra-low-ash gilsonite (< 5%), based on process mineralogy studies and processing tests. For this purpose, mineralogical studies and flotation tests have been performed on a sample of gilsonite with an average ash content of 15%. According to mineralogical studies, carbonates and clay minerals are the main associated impurities (more than 90 vol.%). Furthermore, sulfur was observed in two forms of mineral (pyrite and marcasite) and organic in the structure of gilsonite. Most of these impurities are interlocked with gilsonite in size fractions smaller than 105 µm. The size fraction of + 105 − 420 µm has a higher pure gilsonite (approximately 90%) than other size fractions. By specifying the gangue minerals with gilsonite and the manner and extent of their interlocking with gilsonite, + 75 − 420 µm size fraction selected to perform flotation tests. Flotation tests were performed using different reagents including collector (Gas oil, Kerosene and Pine oil), frother (MIBC) and depressant (sodium silicate, tannic acid, sulfuric acid and sodium cyanide) in different dosages. Based on the results, the use of kerosene collector, MIBC frother and a mixture of sodium silicate, tannic acid, sulfuric acid and sodium cyanide depressant had the most favorable results in gilsonite flotation in the rougher stage. Cleaner and recleaner flotation stages for the rougher flotation concentrate resulted in a product with an ash content of 4.89%. Due to the interlocking of gilsonite with impurities in size fractions − 105 µm, it is better to re-grinding the concentrate of the rougher stage beforehand flotation in the cleaner and recleaner stages. Finally, based on the results of mineralogical studies and processing tests, a processing flowsheet including crushing and initial granulation of gilsonite, flotation in rougher, cleaner and recleaner stages has been proposed to produce gilsonite concentrate with < 5% ash content.

EFFECTS OF INITIAL INHOMOGENEOUS DENSITY DISTRIBUTION AND VOID SHAPE ON POWDER FORGING OF POROUS METAL

2013 ◽  
Vol 27 (19) ◽  
pp. 1341008
Author(s):  
TAIQING DENG ◽  
LIANXI HU ◽  
YU SUN ◽  
XIAOYA LIU
Keyword(s):  
Density Distribution ◽  
Initial Density ◽  
Porous Metal ◽  
Major Axis ◽  
Average Density ◽  
Semi Major Axis ◽  
Punch Force ◽  
Inhomogeneous Density ◽  
Void Shape ◽  
Initial Density Distribution

The deformation behavior during axisymmetric upsetting of sintered metals has been studied based on the finite-element method. The investigation on the effects of the initial density distribution, void shape and die friction on the density distribution and punch force during deformation have been conducted. It was found that under low-friction conditions, the initial density distribution affects the deformation geometry and the density distribution. However, the effect of the initial density distribution was found to be negligible under high-friction conditions. The initial density distribution did not affect the punch force or the average density, regardless of the friction conditions. When the force is perpendicular to semi-major axis of elliptical void, it is not only good for densification but also decrease the punch force in forging of porous metal.

scholarly journals A Feasibility Study Evaluating the Efficiency of Fine Coal Washing Using Gravity Separation Methods

2019 ◽  
Vol 2 (4) ◽  
pp. 497
Author(s):  
Agnes Modiga ◽  
Ndabenhle Sosibo ◽  
Nirdesh Singh ◽  
Getrude Marape
Keyword(s):  
South Africa ◽  
Calorific Value ◽  
Ash Content ◽  
Gravity Separation ◽  
Export Market ◽  
Heavy Liquid ◽  
High Mass ◽  
Fine Coal ◽  
Classifier Performance ◽  
Uranium Industry

Coal mining and washing activities in South Africa often lead to the generation of fine and ultra-fine coal which is in most cases discarded due to high handling and transportation costs. Studies conducted revealed that a large quantity of these fines have market acceptable calorific values and lower ash contents. In order to reduce fines discarded, processes have been developed to re-mine and process the fine coal discards with the aim of improving the calorific value, adding them to coarse washed coal to increase the yield as well as pelletizing the fines so as to meet the market specifications in terms of size. The goal of this study was to evaluate the efficiency of fine coal washing using gravity separation methods and comparing the products thereof to the market specifications with regards to the calorific value and the ash content. Coal fines from the No.4 lower seam of the Witbank coalfield in South Africa resulting from a dry coal sorting plant were subjected to a double-stage spiral test work, heavy liquid separation and reflux classifier test work respectively. The reflux classifier achieved products with low ash content and an increased calorific value, at high mass yields. At higher fluidization water flowrate, the reflux classifier performance was superior to that of the spirals with products of lower ash content and higher calorific value. At low cut point densities, heavy liquid separation yielded the cleanest products with very low ash content but at much lower mass yields. As the density increased, the mass yields increased with the ash content while the calorific value decreased. Most of the products from the different processes met most of the local industries’ specifications but none of them met the export market as well as the gold and uranium industry specifications due to the high ash content.

scholarly journals Chromospheric density distribution, opacity, ionization and windacceleration of 3 K supergiants in ζ aurigae systems

1987 ◽  
Vol 122 ◽  
pp. 319-320
Author(s):  
Klaus-Peter Schröder
Keyword(s):  
High Resolution ◽  
Density Distribution ◽  
Binary Systems ◽  
Average Density ◽  
Absorption Lines ◽  
K Giants

Results from 58 chromospheric eclipse spectra of three ζ Aurigae type binary systems - with a K supergiant primary and a B star companion -taken with IUE at high resolution are presented. Curves of growth have been constructed at 20 phases using selected chromospheric absorption lines superposed upon the B star spectrum. In order to fit average density models to the chromospheres, 3 samples of column densities (for ζ Aur., 32 Cyg. (fig.1) and 31 Cyg. K giants) have been used.

Studies on Regulator Experiment of a High-to-Float High-Ash Fine Coal

2010 ◽  
Vol 26-28 ◽  
pp. 1104-1109
Author(s):  
Xia Hui Gui ◽  
Jiong Tian Liu ◽  
Xiu Xiang Tao ◽  
Yi Jun Cao ◽  
Yong Tian Wang
Keyword(s):  
Production Rate ◽  
Surface Area ◽  
Ash Content ◽  
Sodium Hexametaphosphate ◽  
Separation Index ◽  
Fine Coal ◽  
The Poor ◽  
Soluble Glass

Aim at high-to-float high-ash fine coal with large content of granules, in order to reduce pollution of carried fine slime to quality of concentrate coal, soluble glass, sodium hexametaphosphate and cornstarch these three kinds of regulators were choosen to carry out flotation reducing ash experiment. Result showed that, cause of poor selectivity of fine coal is mainly small quality, big surface area and the poor dispersion of fine coal. When sodium hexametaphosphate dosage is 1500g/t, the kerosene dosage is 370g/t, the foam beater GF dosage is 150g/t, production rate of concentrate coal is 57.69%，and ash content of concentrate coal is 12.04%. Under the same condition, separation index of sodium hexametaphosphate as regulator is superior to cornstarch and soluble glass.

ANALISIS PERBANDINGAN KUALITAS BATUBARA DI LOKASI PENAMBANGAN DAN STOCKPILE DI PT FIRMAN KETAUN PERKASA

2019 ◽  
Vol 4 (01) ◽  
Author(s):  
Andri Toding ◽  
Agus Triantoro ◽  
Riswan Riswan
Keyword(s):  
Calorific Value ◽  
Ash Content ◽  
Total Sulphur ◽  
Fine Coal

Batubara yang ditumpuk di stockpile berasal dari beberapa front atau lokasi penambangan yang berbeda-beda kualitas. Permasalahan yang timbul dari kualitas batubara ini adanya komplain dari pihak konsumen terhadap kualitas batubara yang menyimpang dari kesepakatan standar kualitas batubara yang telah ditentukan. Tujuan dari penelitian ini yaitu menghitung besarnya perbedaan parameter kualitas batubara, melakukan penanganan dan mencari penyebab perbedaan kualitas batubara.Metode yang digunakan dalam penelitian ini adalah dengan melakukan analisis parameter kualitas batubara pada stockpile dan membandingkan dengan hasil analisis parameter kualitas batubara di lokasi penambangan berdasarkan hasil analisis kualitas dari titik bor, serta menganalisis faktor-faktor yang dapat mempengaruhi secara langsung maupun tidak langsung terhadap perbedaan kualitas batubara pada kedua lokasi tersebut. Dilakukan secara lansung dilapangan untuk melihat aktivitas penambangan untuk mengetahui cara penanganan batubara dilokasi penambangan agar tidak terkontaminasi material lain dan cara pengolahan batubara di stock ROM dan penanganan batubara di stockpile untuk mengetahui secara langsung penyebab perbedaan kualitas batubara selama bulan Agustus Tahun 2016.Adapun perbedaan yang terjadi pada  kualitas batubara di lokasi penambangan dan di stockpile yaitu total moisture, ash content, total sulphur dan calorific value. Terjadinya  perbedaan kualitas batubara ini disebabkan oleh faktor-faktor sebagai berikut : kondisi sampling yang tidak baik, aktivitas penambangan, fine coal akibat proses penanganan, ukuran batubara yang tidak seragam dan penanganan batubara di stockpile. Perbedaan kualitas batubara pada lokasi penambangan dan stockpile  seperti TM ar (0,99% – 3,85%), Ash  adb (0,04% – 4,29%), Ash ar  (0,02% – 3,69%),  TS adb (0,01% – 1,25%),  TS ar (0,01% – 0,94%),  CV cal/gr adb (10 – 562), CV cal/gr ar (10 – 355). Kata Kunci :  Lokasi Penambangan, Stockpile, Kualitas Batubara

The Flotation Process with High Intensity Conditioning and Cleaning for Fine Coal

2014 ◽  
Vol 1010-1012 ◽  
pp. 1636-1639 ◽  
Author(s):  
Ji Hui Li ◽  
Li Qiang Ma ◽  
Yan Zhao Li ◽  
Wen Jing Li ◽  
Jian Wei Yue
Keyword(s):  
High Intensity ◽  
Coal Sample ◽  
Ash Content ◽  
Clean Coal ◽  
Flotation Reagents ◽  
Flotation Process ◽  
Fine Coal ◽  
Percentage Points ◽  
Coal Slime

The properties analyzing of flotation feed sample told that this fine coal sample is high-ash and hard-to-float coal slime. The ash reduction comparison of the step-by-step release flotation test with high intensity conditioning (HIC) or not, and the comparison of flotation test with HIC and adding depressant were made. The results showed that HIC can significantly improve the flotation effect for high-ash and hard-to-float coal slime. Comparing with the traditional step-by-step flotation process, if it meets the demand of ash content is 10.00% and 8.00%, the clean coal yield with HIC will increase 18 and 29 percentage points respectively; comparing with the effect of floatation adding depressant, HIC has more help to reduce the ash content and increase the yield of clean coal. In addition, HIC will save a lot of flotation reagents.

scholarly journals Investigation of the effect of several parameters on the applicability of magnetic separation method

2021 ◽  
pp. 69-73
Author(s):  
Tariq Al-Azab ◽  
Jamil Haddad ◽  
Fadi Alfaqs
Keyword(s):  
Magnetic Separation ◽  
Centrifugal Force ◽  
Magnetic Force ◽  
Separation Efficiency ◽  
Industrial Applications ◽  
Separation Process ◽  
Silica Sand ◽  
Sand Particle ◽  
Roll Speed ◽  
Magnetic Separator

Purpose. This research investigates the separation process performed by a magnetic separator. The magnetic separation process is used to isolate ferrous materials from those which are not. Hence, a prototype of a dry magnetic separator is designed. It should be said that this study defines the effect of different parameters (roll speed, magnetic force, and mass of silica sand particle) on separation efficiency. Methodology. The influence of several parameters of the magnetic separator such as magnetic force, centrifugal force, and properties of particle (mass, shape, etc.) were studied theoretically and simulated by SolidWorks software. The optimum conditions of the magnetic separator were obtained, and several trials were performed to find the point that results in a lower effect of roller speed and a higher effect of the magnetic force on the particle in order to achieve higher separating efficiency. Findings. The results show that the centrifugal force are the most important variable influencing separating efficiency. Moreover, it was found that blade angle magnitude of (174) degree with magnetic force between (1.71E-05 to 6.3E-05 N) and roll speed from (84 to 105 rpm) are the optimum separating conditions to reach higher rate of the separating process. Originality. This is the first time that the effect of the gap distance between the magnet and the feeding particles on the magnetic force has been studied. Furthermore, the effect of centrifugal force on magnetic separator force is investigated theoretically and numerically in order to be compared for different parameters. Practical value. The new prototype design of the magnetic separating unit is promising and efficient since the parameters can be varied based on the type and characteristics of materials. It is also revealed that separating time of the materials is reduced. Hence, this type of construction of a magnetic separator is recommended for industrial applications.

scholarly journals Impact of the Automatic Control of a Coal Separation Process in a Jig on its Economic Efficiency

2016 ◽  
Vol 32 (3) ◽  
pp. 163-172
Author(s):  
Stanisław Cierpisz
Keyword(s):  
Control System ◽  
Ash Content ◽  
Density Fluctuations ◽  
Separation Process ◽  
Downward Movement ◽  
Discharge System ◽  
Density Fractions ◽  
Separation Density ◽  
The Impact ◽  
Imperfection Factor

Abstract The beneficiation process of fine coal in jigs consists of two phases: stratification of coal grains in the bed according to their density and then splitting the stratified material into the product and the discharged refuse. At first, during subsequent water pulsations induced by opening and closing of air valves, the stratification of coal grains takes place due to varied velocity of their upward and downward movement. Grains of low density migrate to upper layers and grains of high density migrate to lower layers of the bed. The material travels horizontally on a screen along the jig compartment with the flow of water. The stratification of grains due to their density is not perfect, because the velocity of their upward and downward movement depends in part on their diameter, shape and the way in which the material loosens within a given pulsation cycle. The distribution of coal density fractions in the bed, characterized by the imperfection factor I, has been investigated by many researchers. The imperfection factor I is defined as the ratio of the probable error Ep and the separation density ρ50 (I = Ep/ρ50). The distribution of coal density fractions for an ideal and a real stratification process was compared. The maximum mass of the product of the desired quality (ash content) can be achieved for the ideal process when the imperfection I = 0. The stratified bed is then, in the end part of the jig, split into the product which overflows the end wall of the compartment and the refuse (or middlings) discharged through the bottom gate. The separation density (cut point) is established by the tonnage of the discharged bottom product (opening of the discharge gate). The separation density depends also on the tonnage of raw coal feeding the jig, and its washability characteristics. The impact of variations in the separation density on product parameters has been analysed. The mass of the product is always greater when the separation density is constant over a given period of time – even if in spite of its variations the process renders the same average ash content. Hence, the conclusion is to stabilise the separation density at the desired value as accurately as possible. The analysis was performed for raw coal washed in a three-product jig at the separation densities of 1.5 and 1.8 g/cm3. Percent contents (in brackets) of density fractions in raw coal were: <1.35 g/cm3 (40%), 1.35–1.50 g/cm3 (12%), 1.50–1.65 g/cm3 (4%), 1.65–1.80 g/cm3 (4%), 1.80–1.95 g/cm3 (12%, >1.95 g/cm3 (30%) (average ash in raw coal was 35.5%). In the analysis, an increase in the imperfection by 0.02 resulted in the decrease of the product tonnage by ΔQc = 1.0%. In this case, separation densities were set to ensure the same ash content in products (for I = 0 the change in tonnage was accepted at ΔQc = 0). The simulation analysis presented in the paper focused on the impact that fluctuations in separation density have on the economic effects of a jig operation. The influence of the separation density fluctuations on the product tonnage turned out to be nonlinear; for ±0.04 g/cm3 (control system with the radiometric density meter) the decrease in the product tonnage was ca. 0.5 % and for ±0.12 g/cm3 it was ca. 5.0% (control system with a float). The above results indicate that the operation of a refuse discharge system in a jig plays an important role in the final results of coal separation process defined in terms of tonnage and quality of the product.

scholarly journals Treating Wet Oil in Amara Oil Field Using Nanomaterial (SiO2) With Different Types of De emulsifiers

2021 ◽  
Vol 22 (1) ◽  
pp. 29-38
Author(s):  
Ayat Ragheb Alkarbalaee ◽  
Adel Sharif Hammadi ◽  
Ghassan Hamid Abdul Majeed
Keyword(s):  
Acidic Medium ◽  
Separation Efficiency ◽  
Sodium Dodecyl ◽  
Separation Process ◽  
Oil Field ◽  
Oil Refining ◽  
Ph Values ◽  
Different Types ◽  
Separation Results ◽  
High Separation

One of the most important problems in the oil production process and when its continuous flow, is emulsified oil (w/o emulsion), which in turn causes many problems, from the production line to the extended pipelines that are then transported to the oil refining process. It was observed that the nanomaterial (SiO2) supported the separation process by adding it to the emulsion sample and showed a high separation rate with the demulsifiers (RB6000) and (sebamax) where the percentage of separation was greater than (90 and 80 )%  respectively, and less than that when dealing with (Sodium dodecyl sulfate and Diethylene glycol), the percentage of separation was (60% and 50%) respectively.    The high proportion of (NaCl + distilled water) raises the probability of the separation efficiency as the separation was (88.5,79)% and (65.5, 55) %  for (RB6000, SebaMax)respectively with (SiO2) at 70 °C, while the results of separation were (77,85)% and (65,40)  for (RB6000, Seba Max) respectively with (SiO2) at 50 °C after 120 minutes, where the (w/o ratio) was (9:1) for the high separation results and (7:3) for the lower separation results, at a speed of (12000rpm), and with a salt concentration of (1500) ppm, and less of these results at lower volumetric and temporal conditions. The (NaCl) salt deals with the wall films separating the droplets and reduces their viscosity [1].    As for the pH factor, it is at the value (2 and 3) represent a stable emulsion that is difficult to separate easily, but with the passage of raising the pH away from the acidic medium and near to the basic direction, a significant increase in the separation process was observed compared with the acidic medium at lower values, after 120 minutes the separation seemed to be good efficient, reaching (60 and 70) % respectively, while at the same time the emulsion reached a more efficient separation level with a pH of (  8 and 7) equal to (80 and 87.3)  %, at 50 °C with SebaMax demulsifier in presence of (SiO2), and with the same pH values, an increase was observed in the separation with the increase in temperature to (70 °C), then it returns to be a reverse emulsifier when the value exceeds (10) to (11, 12, 13).

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