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.

Experimental Research of Roughing and Cleaning Column Flotation of Difficult-to-Float High Ash Coal

2014 ◽  
Vol 1010-1012 ◽  
pp. 1603-1608 ◽  
Author(s):  
Jian Zhong Wang ◽  
Xian Bo Zhang ◽  
Hai Bin Qin ◽  
Li Tan
Keyword(s):  
Coal Sample ◽  
Ash Content ◽  
Clean Coal ◽  
Flotation Concentrate ◽  
Flotation Column ◽  
Flotation Tailing ◽  
Concentrate Yield ◽  
Coal Slime ◽  
High Ash Coal ◽  
Preparation Plant

Coal slime in Zhongcheng coal preparation plant in Baotou, Inner Mongolia, was analyzed. It is found that this coal sample is with high inner ash content and very difficult to float. It is hard to obtain low ash concentrate and high ash tailing with primary flotation. The live scale required ash content is 12.00% for total clean coal, 15.00% for flotation concentrate. It is found that the lowest concentrate ash content is 29.24% through exploring flotation experiments, which can not meet the producing requirement. Results of timed release flotation experiment show that when concentrate ash content is 15.00%, the theoretical concentrate yield is 24.36%, with 50.03% of flotation tailing ash content and 35.49% of combustible matter recovery. It can be concluded that the floatable grade of this coal sample is Very Difficult to Float. So flotation column is taken into account. The lowest concentrate ash content of roughing flotation by flotation column is 18.94%, which does not meet the requirement, either. Results of cleaning flotation of roughing flotation concentrate show that when the recycling pressure is 0.14 MPa, the concentrate ash content is 14.15% with a yield of 30.39%, which is satisfactory and can be referred to direct industrial production.

scholarly journals Improving Coal Flotation by Gaseous Collector Pretreatment Method and its Potential Application in Preparing Coal Water Slurry

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 500 ◽  
Author(s):  
Shen ◽  
Min ◽  
Liu ◽  
Xue ◽  
Zhu
Keyword(s):  
Contact Angle ◽  
Coal Sample ◽  
Ash Content ◽  
Low Rank ◽  
Distribution Analysis ◽  
Low Rank Coal ◽  
Clean Coal ◽  
Pretreatment Method ◽  
Water Slurry ◽  
Coal Water Slurry

Low-rank coal is difficult to upgrade using conventional flotation methods due to its high hydrophilic properties. Thus, it is necessary to explore new methods for upgrading and utilizing low-rank coal. In this investigation, a gaseous dodecane pretreatment method was used to enhance the flotation performance of low-rank coal. Pore distribution analysis, FTIR (Fourier Transform Infrared Spectroscopy), and contact angle measurements were used to study the surface properties of the coal sample. Size distribution and float-sink test results indicated that the coal sample contained a lot of clean coal with low ash content, which could be used as a high quality raw material for making coal water slurry. FTIR, pore distribution analysis, and contact angle results showed that the coal was very hydrophilic due to the high concentration of -OH group and the large number of pores and cracks on the coal surface. The hydrophobicity of the coal sample was significantly improved by the gaseous dodecane pretreatment method. Clean coal with 67.2% combustible matter recovery and 10.5% ash content was obtained by gaseous dodecane pretreatment flotation method. Coal water slurry with 60% concentration was prepared using the flotation clean coal.

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.

Lower Ash Experimental Study on New Slime Separator

2014 ◽  
Vol 955-959 ◽  
pp. 2813-2817
Author(s):  
Ling Zhang ◽  
Yi Shun Zhang ◽  
Chang Liang Shi ◽  
Yuan Yang Liu ◽  
Fei Yue Wang
Keyword(s):  
Experimental Study ◽  
Water System ◽  
Flotation Reagents ◽  
Circulating Water ◽  
Fine Coal ◽  
Coal Slime ◽  
Circulating Water System ◽  
The Cost

The flotation is the effective method to fine coal separation, but the cost is higher and flotation reagents pollute circulating water system. In this paper, the JiuLiShan coarse coal slim was classified, the interception of 0.25 mm was collected, fine coal float-and sink test was carried out. For the-0.25mm coarse slime, compare the flotation, conventional coarse coal slime separation and new slime separator separation, the results show: underflow ash increased by 12.4%;the new slime separator is suitable for the 0.25 mm granularity fine coal slime, can be applied to lower fine slime ash, raising cleaned coal yield.

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.

The Application and Development of Microbubble Column Flotation Technology in China

2010 ◽  
Vol 136 ◽  
pp. 194-201 ◽  
Author(s):  
Yong Tian Wang
Keyword(s):  
Mineral Processing ◽  
Dense Medium ◽  
Column Flotation ◽  
Flotation Process ◽  
Fine Coal ◽  
Column Type ◽  
Flotation Columns ◽  
Efficient Column ◽  
Coal Slime ◽  
High Ash Coal

Since the early 1980s, great progress has been made in microbubble column flotation technology. As one of the important mineral processing methods, the application and development of this technology in China are summarized in this paper from four respects. Firstly, a patented cyclone- static microbubble separation method was proposed to overcome the notable problems mentioned in the previous flotation columns. Secondly, microbuble column flotation was introduced to separate the high ash as well hard-to-separate coal slime generated from dense medium processes. The characteristics of the microbubble column, and the flotation process for fine coal and the high ash coal separation was analyzed. Thirdly, the application of microbubble column flotation in China was detailed introduced, especially the characteristics of series microbubble column flotation equipment, and efficient column type coal slime separation crafts were discussed. The application of microbubble column flotation particularly in low ash content coal preparation, and discarded coal slime processing technology were presented. Finally, microbubble column flotation has been extended to non-coal mineral processing, such as magnetite concentrate upgrading (concentration iron and removing silicon), sulfide copper mine separation, white tungsten flotation, etc., the related research was briefly introduced in this paper as well.

scholarly journals Optimization of Coal Washery Tailings by Flotation Process

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3956 ◽  
Author(s):  
Changliang Shi ◽  
Gan Cheng ◽  
Shengnan Wang
Keyword(s):  
Inflation Rate ◽  
Calorific Value ◽  
Ash Content ◽  
Cultivated Land ◽  
Clean Coal ◽  
Flotation Process ◽  
Flotation Tailings ◽  
Flotation Performance ◽  
Coal Washery ◽  
By Products

Flotation tailings are by-products of coal preparation plants, which do not only occupy cultivated land but also cause pollution. The high ash content and low calorific value of tailings limit their applications. Deashing is the precondition for the reutilization of flotation tailings. However, it is more difficult to remove ash content from flotation tailings compared with raw coal. Based on the analysis of coal properties, the flotation performance of different collectors was compared in this study. Flotation flows and the mechanism of depressants were explored. The optimized flotation conditions were as follows: pulp concentration of 100 g/L, inflation rate of 0.25 m3/(m2·min), collector (C4) dosage of 300 g/t, frother dosage of 500 g/t, and revolving speed of 2200 rpm. The ash content of clean coal was also reduced by adding a depressant. The flotation performance was best when the amount of sodium hexametaphosphate (used as the depressant) was 4 kg/t; the recovery of clean coal was 71.88%, and the ash content was 10.64%.

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.

Collecting behaviors of high internal phase (HIP) emulsion in flotation of ultrafine high-ash content coal slime

2021 ◽  
pp. 1-21
Author(s):  
Xuemin Zhao ◽  
Yunmin Tang ◽  
Binglong Zhao ◽  
Changning Wu ◽  
Junguo Li ◽  
...  
Keyword(s):  
Ash Content ◽  
Internal Phase ◽  
Coal Slime

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.

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