The synchronous production of high-quality unburned carbon concentrate and cleaned ash from high LOI (loss on ignition) fly ash without yielding secondary solid waste is a dilemma issue. In this study, a viable flotation process with one rougher and two cleaners is developed for simultaneously obtaining carbon concentrate with a yield of 18.00% and an …
A device using the flotation method to remove unburned carbon in fly ash was developed, and the operating condition of the device was experimentally examined. …
Flotation is a considerably superior process for the removal of the UC from fly ash than other physical means, which include electrostatic separation and ultrasonic column agglomeration [14]. Froth flotation has been widely used to remove the UC from fly ash according to the theory that the UC in fly ash differs in terms of its affinity to ...
This paper introduces chemical compositions of a typical coal ash and a dry beneficiation method. For some kinds of fly ash, magnetically stabilized fluidized bed was studied to recover magnetic ...
1. Introduction. Coal fly ash is a by-product of coal combustion in thermal power plants, and it causes serious pollution of the surrounding soil, air, and water [1], [2].The latest global annual coal fly ash production is estimated to be 750 million tonnes [3].To alleviate the pressure of storing coal fly ash, the extraction of valuable elements, …
The wet magnetic separation used in the study increased the magnetite content in the magnetic fraction from 10.48 to 12.72 wt % compared to dry magnetic separation.
It has been stated previously that cenospheres are generally obtained from cenospheric fly ash using a wet-separation process, typically of the lagoon type. Normally, the ratio of water to cenospheric fly ash is between 10:1 and 3.5:1 (Sear, 2001). Due to this operation, there is a possibility of leaching of toxic materials from the …
Hence, the efficient flotation to separate and enrich the carbon content of fine slag can be considered an important way to achieve raw fine slag upgrading. This was also reported in the coal fly ash field [20], [37]. The HHV of flotation residual carbon is elevated to 19.48 MJ/kg after a three-step froth flotation process.
Decarburization process such as dry separation (sieving and triboelectrostatic separation) and wet separation (froth flotation and gravity separation) are developed to reduce the UC in fly ash. Sieving utilizes the size distribution characteristics of UC to achieve the removal effect which based on a measurable …
The unburned carbon in fly ash inhibits the performance of concrete. A device using the flotation method to remove unburned carbon in fly ash was developed, and the operating condition of the device was experimentally examined. According to the results, the device was able to remove unburnt carbon from fly ash by using the installed …
Decarbonization of fly ash by electrostatic separation is primarily based on the difference in electrical property of ash and carbon in the fly ash [13], [14], [15]. Relatively pure carbon and ash used for electric characterization in this study were prepared from the fly ash sample by froth flotation separation method.
The flotation removing of unburned carbon demonstrates that an effective separation of unburned carbon from coal fly ash could be achieved by using the surfactant humic acid during flotation process. The maximum removal rate of carbon is 93.20 ± 0.05% under the optimized condition.
By optimizing the flotation condition, 41.9% total PCDD/Fs, 40.8% coplanar PCBs, and 44.1% PCBs with 64.0% UC have been successfully removed from MSWI fly ash. The total toxic equivalent (TEQ) of the fly ash was decreased from 6.2 ng/g to 4.2 ng/g in the residue. *
Laboratory NBs flotation tests were carried out with the apparatus shown in Fig. 2 to investigate the influence of key flotation process variables on flotation performance and assess the technical feasibility of enhanced fly ash flotation performance by use of NBs. The testing apparatus consisted of a 5 L in volume, 5 cm in diameter …
In general, high-carbon fly ash can be beneficiated using dry and wet separation processes, such as froth flotation, electrostatic separation, fluidized bed reactors, oil agglomeration, density separation, and sieving [16,17,18,19]. Each separation method has disadvantages and advantages and can be adapted for different types of …
The unburned carbon content of fly ash from two different power stations was greatly reduced in two-stage laboratory flotation tests by employing a collector consisting of …
Liu et al. (2013a) applied a floatation process for removal of carbon and unburned carbon contents from incinerator ash that increased the loss on ignition of fly ash from 11.1% to 31.6% during ...
The ash treatment includes three stages: 1) magnetic separation of an iron-containing fraction, 2) carbon separation by floatation, and 3) extraction of aluminum by the autoclave hydrochloric acid leaching. The lab-scale results of the ash treatment applied to the Ekibastuz brown coal fly ash from the Omsk power stations (Russia) were …
The unburned carbon content of fly ash from two different power stations was greatly reduced in two-stage laboratory flotation tests by employing a collector consisting of nonylphenol and either hexadecane or fuel oil together with methyl isobutinol (MIBC) as a frother. The tailings from the first stage were recleaned in the second stage. This method …
The chemical compositions of fly ash are given in Table 1. The lime content of the fly ash sample was 1.43%; this slight amount can result in high alkaline solutions. Prior to cenosphere separation, the fly ash sample was oven-dried at 105 °C for 24 h. The separation of cenospheres was performed through the wet separation process sink …
This paper focuses on the turbulent properties in the outflow generated by the Rushton turbine in a stirred tank and the conditioning-flotation tests of the flotation …
Such process includes three stages of magnetic separation for iron separation, floatation for carbon separation, and autoclave pressure leaching in acid solution [187]. Pressure leaching carried ...
Current common methods of reducing the unburned carbon in fly ash are dry separation (e.g., screening and friction electrostatic separation) and wet separation (e.g., flotation and gravity ...
Column flotation tests indicated that the FCSMC method a viable and effective separation process for removing the unburned carbon from the fly ash. Under the optimized conditions, a clean ash with ...
Unburned carbon can be recovered from fly ash by sieving, gravity separation, froth flotation, oil agglomeration and electrostatic separation (Sahoo et al., 2016; Xing et al., 2019). Removing ...
Flotation column flotation, anti–flotation, multi–step flotation, hydrophobic–hydrophilic separation, ultrasonic synchronous flotation, collector mineralized particles under low–speed shearing, carrier flotation, flotation vortex regulation, and a combination of sorting processes can effectively reduce the ash …
In this paper, the use of froth flotation to remove the unburned carbon from fly ash is described. Three different fly ashes were studied that had loss-on-ignition (LOI) values of 6.79, 6.90, and ...
Cenospheres are valuable material contained inside the fly ash. Its low weight, low density, and high strength made it very versatile and can be used in various fields. The way of separating the cenosphere from the fly ash consists of two categories, wet and dry separation. For wet separation, it involves submerging the fly ash inside a …
Thus, the proposed pre-classification and flotation process can improve the quality of coal fly ash. The results provide a theoretical basis for the harmless and resource treatment of coal fly ash. Graphical Abstract. Download : ... Wet separation processes of coal fly ash include gravity separation, oil agglomeration separation, and froth ...
Fly ash (FA) is a complex and abundant solid waste created by humans, and has caused environmental issues, for which flotation is an effective technique employed before its comprehensive utilization.