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%.

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.

Energetic properties of peat saturated with petroleum products

2020 ◽  
Vol 13 (2) ◽  
pp. 105-109
Author(s):  
E. S. Dremicheva
Keyword(s):  
Crude Oil ◽  
Diesel Fuel ◽  
Energy Use ◽  
Experimental Studies ◽  
Calorific Value ◽  
Petroleum Products ◽  
Ash Content ◽  
Motor Oil ◽  
Initial Sample

This paper presents a method of sorption using peat for elimination of emergency spills of crude oil and petroleum products and the possibility of energy use of oil-saturated peat. The results of assessment of the sorbent capacity of peat are presented, with waste motor oil and diesel fuel chosen as petroleum products. Natural peat has been found to possess sorption properties in relation to petroleum products. The sorbent capacity of peat can be observed from the first minutes of contact with motor oil and diesel fuel, and significantly depends on their viscosity. For the evaluation of thermal properties of peat saturated with petroleum products, experimental studies have been conducted on determination of moisture and ash content of as-fired fuel. It is shown that adsorbed oil increases the moisture and ash content of peat in comparison with the initial sample. Therefore, when intended for energy use, peat saturated with petroleum products is to be subjected to additional drying. Simulation of net calorific value has been performed based on the calorific values of peat and petroleum products with different ratios of petroleum product content in peat and for a saturated peat sample. The obtained results are compared with those of experiments conducted in a calorimetric bomb and recalculated for net calorific value. A satisfactory discrepancy is obtained, which amounts to about 12%. Options have been considered providing for combustion of saturated peat as fuel (burnt per se and combined with a solid fuel) and processing it to produce liquid, gaseous and solid fuels. Peat can be used to solve environmental problems of elimination of emergency spills of crude oil and petroleum products and as an additional resource in solving the problem of finding affordable energy.

scholarly journals Performance Optimisation of Fuel Pellets Comprising Pepper Stem and Coffee Grounds through Mixing Ratios and Torrefaction

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4667
Author(s):  
Sunyong Park ◽  
Hui-Rim Jeong ◽  
Yun-A Shin ◽  
Seok-Jun Kim ◽  
Young-Min Ju ◽  
...  
Keyword(s):  
Calorific Value ◽  
Basic Information ◽  
Spent Coffee Grounds ◽  
Mixing Ratios ◽  
Moisture Contents ◽  
Fuel Pellets ◽  
Coffee Grounds ◽  
Coffee Ground ◽  
Fuel Characteristics ◽  
By Products

Agricultural by-products have several disadvantages as fuel, such as low calorific values and high ash contents. To address these disadvantages, this study examined the mixing of agricultural by-products and spent coffee grounds, for use as a solid fuel, and the improvement of fuel characteristics through torrefaction. Pepper stems and spent coffee grounds were first dried to moisture contents of <15% and then combined, with mixing ratios varying from 9:1 to 6:4. Fuel pellets were produced from these mixtures using a commercial pelletiser, evaluated against various standards, and classified as grade A, B, or Bio-SRF. The optimal ratio of pepper stems to spent coffee grounds was determined to be 8:2. The pellets were torrefied to improve their fuel characteristics. Different torrefaction temperatures improved the mass yields of the pellets to between 50.87% and 88.27%. The calorific value increased from 19.9% to 26.8% at 290 °C. The optimal torrefaction temperature for coffee ground pellets was 230 °C, while for other pellets, it was 250 °C. This study provides basic information on the potential enhancement of agricultural by-products for fuel applications.

scholarly journals Flotation performance analysis on coal washery rejects

2021 ◽  
Author(s):  
P. Sharath Kumar ◽  
O. Sivrikaya ◽  
S. Pradhan ◽  
P.C. Nagannor
Keyword(s):  
Performance Analysis ◽  
Flotation Performance ◽  
Coal Washery

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.

Potensi Nilai Kalor Biomassa Dari Ampas Tebu (Bagasse) Yang Bersumber Dari Penjual Minuman Sari Tebu Di Kota Pontianak

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Reza Wahyudi ◽  
Muhammad Ivanto ◽  
Murti Juliandari
Keyword(s):  
Laboratory Testing ◽  
Energy Supply ◽  
Alternative Fuels ◽  
Fossil Fuels ◽  
Calorific Value ◽  
Ash Content ◽  
Sugarcane Juice ◽  
Test Results ◽  
Supply Problem ◽  
Direct Data

Dependence on the provision of electricity using fossil fuels is a major energy supply problem in Indonesia. Therefore, it is necessary to provide new and renewable alternative fuels that are effective, efficient, and environmentally friendly. One of the alternative fuels is bagasse biomass. The purpose of this study was to determine the amount of bagasse produced by sellers of sugarcane juice drink in Pontianak City, in order to determine the estimated value of bagasse. The research method used was direct data collection and laboratory testing . Based on the results of the study, the number of vendors of sugarcane juice beverages producing bagasse was 169. Of this amount, produce bagasse that can reach 1,030.9 kg/day. Based on the test results, the estimated moisture content of bagasse was 3.28%, ash content was 0.77%, and carbon remained at 7.65%. So, if converted with the test results of the calorific value of bagasse and made into briquettes bagasse (bio briquettes), which is 19,648 kJ/kg with a density of 0.416 kg/m3, then converted into a potential calorific value of 242,849,280 J/year.

scholarly journals Valorization of briquettes fuel using Pinus spp. sawdust from five regions of Mexico

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 2249-2263
Author(s):  
María Alejandra Ramírez-Ramírez ◽  
Artemio Carrillo-Parra ◽  
Faustino Ruíz-Aquino ◽  
Luis Fernando Pintor-Ibarra ◽  
Nicolás González-Ortega ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Impact Resistance ◽  
Resistance Index ◽  
Calorific Value ◽  
Volatile Matter ◽  
Ash Content ◽  
Fixed Carbon ◽  
Volumetric Expansion ◽  
Pinus Spp ◽  
The Impact

This research characterized briquettes made with Pinus spp. sawdust without the use of additives. For this purpose, 19 samples of sawdust from different wood industries located in five states of the Mexican Republic were used. The densification process was carried out in a vertical hydraulic piston laboratory briquette machine. The briquettes were made with 40 g of sawdust, at 50 °C, 20 kPa and pressing for 5 min. The results obtained varied as follows: moisture content (4.1% to 7.2%), density (813.9 to 1,014.4 kg/m3), volumetric expansion (7.4% to 37.3%), compressive strength (4.9 to 40.8 N/mm), impact resistance index (46.7% to 200%), ash (0.1% to 1.1%), volatile matter (82.9% to 90.7%), fixed carbon (8.9% to 16.4%), and calorific value (20.5 to 22.8 MJ/kg). The density of the briquettes was within the “acceptable” classification (800 to 1,200 kg/m3). It was observed that, the higher the density, the lower the volumetric expansion, the higher the compressive strength, and the higher the impact resistance index. According to the ash content, the briquettes could achieve international quality. Due to high volatile matter values, rapid combustion of the briquettes with little generation of toxic smoke would be expected. Fixed carbon and calorific value results were acceptable.

scholarly journals Sedimentology and Economic Significance of Hangu Formation, Northwest Pakistan

2020 ◽  
Vol 11 (1) ◽  
pp. 48-55
Author(s):  
Kamil Ahmed Qureshi ◽  
Muhammad Raza Shah ◽  
Ishaque Ali Meerani ◽  
Shah Fahad ◽  
Hamid Hussain ◽  
...  
Keyword(s):  
Coal Seam ◽  
Carbon Content ◽  
Calorific Value ◽  
Chemical Study ◽  
Ash Content ◽  
Coarse Grained ◽  
Carbonaceous Shale ◽  
Sedimentary Structures ◽  
Economic Significance ◽  
Quartz Arenite

The Hangu Formation (Paleocene) consists of sandstone, siltstone, carbonaceous shale, coal and laterite. It is well exposed in the Trans Indus Surghar range and the southern Hazara basin. The sandstone is yellowish brown, fine to coarse grained and medium to thick bedded. The sandstone of the Hangu Formation is classified as quartz arenite on the Q-F-L diagram. It is mostly grain supported and are cemented by silica cement. The study of different stratigraphic sections reveal that Hangu Formation can be sub-divided into a number of lithofacies on the basis of sedimentary structures and lithological variations. These include lateritic lithofacies, coal and carbonaceous shale, cross-bedded sandstone, bioclastic limestone and bioturbated sandstone. All these lithofacies are well-developed in the Baroch Nala section of the Surghar range except the lateritic lithofacies which contains a thin bed of ferruginous clay. In the studied sections of the Hazara basin, the lateritic lithofacies is the only well-developed lithofacies present in the area. The coal occurs at two stratigraphic levels in the Baroch Nala section. The lower coal seam is thick and its chemical study indicates higher calorific value and carbon content than the upper coal seam and with low moisture/ash content. On the basis of the calorific value, the coal of the Hangu Formation is characterized as high volatile bituminous. The degree of laterization is strong in the Langrial and Khanpur sections and moderate in Baroch Nala section.

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