Process to Reduce Ash in Flotation of Hard-to-Float Fine Coal

2014 ◽  
Vol 508 ◽  
pp. 133-136
Author(s):  
Ji Hui Li ◽  
Li Qiang Ma ◽  
Gong Cheng ◽  
Xiao Hui Liu ◽  
Zhong Ling Zhang ◽  
...  
Keyword(s):  
Coal Sample ◽  
Ash Content ◽  
Feed Concentration ◽  
Coal Flotation ◽  
Fine Coal ◽  
Depressant Action ◽  
Action Time

The most proportion of mineral impurities in this coal sample is Kaolin, which is very argilliferous and harmful for fine coal flotation. In this paper, the authors use recleaning process and add depressant inslurryto reduce the concentrate ash. The results show that the most appropriate depressant is sodium haxametaphosphate and the best flotation conditions are 80g/L feed concentration, 0.80l/t Kerosene dosage, 0.06l/t 2-octyl alcohol dosage, approximately 800g/t sodium haxametaphosphate dosage, and 4 minutes depressant action time. Consequently, the concentrate ash content decreases 5% than batch-floatation test.

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 Effect of ash existence in the coal particles on the dewatering performance of fine coal

2020 ◽  
Author(s):  
Suhong Zhang ◽  
Ni Gao ◽  
Ke Zhao
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Moisture Content ◽  
Coal Sample ◽  
Ash Content ◽  
Primary Role ◽  
Fine Coal ◽  
Angle Measurements ◽  
Coal Particles ◽  
Contact Angle Measurements

Abstract The dewatering experiments of fine coal with different ash contents in the particle size range of 0.125 mm − 0 mm were investigated in this study. Structures of coal samples were characterized by X-ray diffractometer (XRD) and surface functional groups were detected by Fourier transform infrared (FTIR). Wettability and wetting heats of coal samples were determined by contact angle measurements and micro-calorimeter system, respectively. In this study, the dewatering results indicate that the ash content of fine coal had less effect on the coal dewatering than the coalification degree in the dewatering process. However, for the given coal sample the moisture content was significantly affected by the ash content while the coal particle size was less than 0.125 mm. The decrease of moisture content in coal sample after the ash was removed indicating that the hydrophobic property of coal surface was enhanced based on contact angle measurements and wetting heats. In addition, kaolinite played a primary role of minerals in coal for the coal dewatering.

scholarly journals Reduction of Ash Content in Raw Coal Using Acids and Alkali

2010 ◽  
Vol 7 (4) ◽  
pp. 1254-1257 ◽  
Author(s):  
K. H. Shivaprasad ◽  
M. M. Nagabhushana ◽  
C. Venkataiah
Keyword(s):  
Sulfuric Acid ◽  
Hydrochloric Acid ◽  
Coal Sample ◽  
Toxic Elements ◽  
Thermal Power ◽  
Calorific Value ◽  
Ash Content ◽  
Subsequent Removal ◽  
Inorganic Matter ◽  
Leaching Experiments

Ash, an inorganic matter present in coal is amenable for dissolution using suitable reagents. Thus the dissolution of ash and its subsequent removal reduces the release of many toxic elements into the environment by coal based industries. Removal of ash also enhances the calorific value. In the present investigation an attempt has been made to reduce the ash content of raw coal obtained from nearest thermal power by using hydrochloric acid, sulfuric acid and sodium hydroxide. A series of leaching experiments were conducted on coal of different size fractions by varying the parameters like concentration, temperature and time of leaching. The results indicate that it is possible to remove nearly 75% of ash from coal sample by leaching.

Role of Magnesium Salts in Coal De-Ashing by Flotation

2021 ◽  
Vol 58 (1) ◽  
pp. 51-58
Author(s):  
Rawya Gamal ◽  
Nader A.A. Edress ◽  
Khaled A. Abuhasel ◽  
Ayman A. El-Midany ◽  
Salah E. El-Mofty
Keyword(s):  
Particle Size ◽  
Strong Interaction ◽  
Statistical Design ◽  
Ash Content ◽  
The Other ◽  
Pulp Density ◽  
Statistical Design Of Experiments ◽  
Coal Flotation ◽  
Magnesium Salts

Abstract The most frequently investigated salts in coal flotation are chlorides. However, seawater contains additional salts such as sulfates. In coal flotation, magnesium chlorides showed the best results in terms of higher yield and lower ash content compared to the other magnesium salts studied. Therefore, two magnesium salts were tested in this investigation, namely magnesium chloride and magnesium sulfate. The effect of the magnesium salts as well as the optimization of coal flotation were investigated by statistical design of experiments in terms of pulp density, particle size, conditioning time and different dosages of MgCl2 and MgSO4. The flotation results obtained by statistical design show that the ash content was lowest at 8.2% when a mixture of 2 kg/t MgSO4 and 2 kg/t MgCl2 has been used, with pulp density 20%, particle size 400 lm and conditioning time 15 min. The particle size plays an important role in reducing the ash content when the conditioning time has been extended and pulp density has been reduced. The strong interaction between the salts hinders the reduction of the ash content to less than 8.2%.

scholarly journals Coal surface control for advanced fine coal flotation. Quarterly report No. 5, October 1, 1989--December 31, 1989

1990 ◽  
Author(s):  
D. W. Fuerstenau ◽  
Sastry, K. V.S. ◽  
J. S. Hanson ◽  
K. S. Narayanan ◽  
F. Sotillo ◽  
...  
Keyword(s):  
Coal Surface ◽  
Coal Flotation ◽  
Fine Coal ◽  
Surface Control

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 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.

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.

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