scholarly journals Preparation of fly ash-based flocculant and flocculation performance

2021 ◽  
Vol 2079 (1) ◽  
pp. 012006
Author(s):  
Junxin Zhang ◽  
Xiumei Duan

Abstract Using fly ash from a thermal power plant in Yingkou City as raw material, The inorganic polymer flocculant polyaluminum ferric chloride (PAFC) was prepared by sodium carbonate impregnation, high temperature roasting activation, and acid leaching. The influence of activation temperature and activation time on the leaching of aluminum and iron was investigated through single factor test and orthogonal test. The PAFC preparation conditions were optimized, and the prepared PAFC flocculant product was applied to kaolin turbidity water. The test results showed that the content of aluminum in fly ash was 7.08%, and the content of iron was 4.95%. The mass ratio of the activator sodium carbonate and fly ash was 10:7, the activation temperature was 800°C, and the activation time was 2h. The leaching rates of aluminum and iron were the highest, 88.31% and 53.66% respectively. The optimal conditions for the preparation of the flocculant were as follows: the molar ratio of aluminum to iron was 5.7:1, and the reaction time was 1.5h. The liquid product obtained under these conditions was yellowish brown, and the solid product obtained after being dried was yellow powder.

2014 ◽  
Vol 953-954 ◽  
pp. 173-177 ◽  
Author(s):  
Zhen Wu ◽  
Ning Xu ◽  
Lei Hu ◽  
Ben Lin Dai ◽  
Jia Xing Xu

Enzymatic hydrolysis lignin was prepared and used to converse into aromatic aldehydes by catalytic wet oxidation with activation of Fenton reagent. The results demonstrated that the enzymatic hydrolysis lignin was a suitable raw material for the preparation of aromatic aldehydes. Orthogonal experiments were conducted to obtain the optimum preparation conditions. The effects of activation time, activation temperature, ratio of liquid to solid and pH of the reaction system on the yield of aromatic aldehydes were dealt with in this paper and optimal activation conditions were obtained as followed: the pH of activating reaction system was 4, activation temperature was 60°C, ratio of liquid to solid was 20:1 and activation time was 30 min. The highest yield of 13.74 % was obtained under the optimum conditions.


2012 ◽  
Vol 490-495 ◽  
pp. 3540-3544
Author(s):  
Shu Guang Ouyang ◽  
Le Le Fu ◽  
Zhi Wang

An orthogonal experiment is conducted to study the effect of activation temperature, activation time and the ratio of KOH to carbon material (i.e. the mass ratio of KOH to coking fly ash) on the adsorption capacities of the activated carbon made by using coking fly ash as the raw material and KOH the activating agent. The results show that the three factors can be ordered as activation temperature, activation time and the ratio of KOH to carbon material according to the significance in their effect on preparation of activated carbon from coking fly ash. In addition, the optimum activation temperature is 850°C, optimum activation time 30minutes, and the optimum ratio of KOH to carbon material 4:1. For the activated carbon made under these conditions, the iodine absorption capacity is 874.3774mg/g, specific surface-area 275.51m2/g, the mean pore diameter 47.75nm and total pore volume 0.1172cm3/g. As the proportion of mesoporouses reaches 71.57%, the activated carbon made from coking fly ash is good for absorption of those absorbates with higher molecular weights.


2013 ◽  
Vol 401-403 ◽  
pp. 679-682
Author(s):  
Chun Hua Yuan

Using the main raw material of fly ash, metal scrap and waste industrial acid, with the activating method of specific self-activator ,can prepare poly-ferric-aluminum-silicate(PFAS) flocculant of inorganic polymeric coagulates. Specific activator can effectively open the Si-Al bond in the fly-ash, greatly enhance the leaching rate of each element by adding a special activator (M), the added amount of M: SiO2 = 1:3, activation time of 1 hour, activation temperature to 900 °C, get the original product, on 65 °C with turbid acid to stir and leach, leaching time is 2 hours, get the best rate of leaching. By Controlling Molar ratio of (Al + Fe) and Si 1:1, Silicic acid polymerization pH 1.7, by choosing the appropriate amounts of flocculants and flocculation time ,can get the very good flocculation function, the light transmission rate of the handling-water may amount to more than 92.7%.


2013 ◽  
Vol 12 (2) ◽  
pp. 337-342 ◽  
Author(s):  
Firuta Goga ◽  
Roxana Dudric ◽  
Calin Cormos ◽  
Florica Imre ◽  
Liliana Bizo ◽  
...  

2021 ◽  
Vol 5 (6) ◽  
pp. 151
Author(s):  
Mustapha El Kanzaoui ◽  
Chouaib Ennawaoui ◽  
Saleh Eladaoui ◽  
Abdelowahed Hajjaji ◽  
Abdellah Guenbour ◽  
...  

Given the amount of industrial waste produced and collected in the world today, a recycling and recovery process is needed. The study carried out on this subject focuses on the valorization of one of these industrial wastes, namely the fly ash produced by an ultra-supercritical coal power plant. This paper describes the use and recovery of fly ash as a high percentage reinforcement for the development of a new high-performance composite material for use in various fields. The raw material, fly ash, comes from the staged combustion of coal, which occurs in the furnace of an ultra-supercritical boiler of a coal-fired power plant. Mechanical compression, thermal conductivity, and erosion tests are used to study the mechanical, thermal, and erosion behavior of this new composite material. The mineralogical and textural analyses of samples were characterized using Scanning Electron Microscopy (SEM). SEM confirmed the formation of a new composite by a polymerization reaction. The results obtained are very remarkable, with a high Young’s modulus and a criterion of insulation, which approves the presence of a potential to be exploited in the different fields of materials. In conclusion, the composite material presented in this study has great potential for building material and could represent interesting candidates for the smart city.


Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1922
Author(s):  
Anastasiia V. Dubenko ◽  
Mykola V. Nikolenko ◽  
Oleksandr O. Pasenko ◽  
Andrii Kostyniuk ◽  
Blaž Likozar

A new method of altered ilmenite processing has been studied. In this method, sulfuric acid is used as the reaction medium of the process, and fluoride ions are activators of the dissolving process of the rutile part of the ore raw material. The regression model of the sulfate–fluoride leaching process was developed and analyzed by using the response surface method of 23 matrix. The obtained model is adequate and well describes the studied process. The influence of Ti:F molar ratio, temperature, and sulfuric acid concentration on the leaching process are investigated in this work in order to optimize the studied process. It is experimentally proved that leaching at temperatures above 100 °C, at a molar ratio of Ti:F of more than 1:2, and the use of solutions of sulfuric acid with concentrations of more than 85 wt.% is not optimal because the extraction degree of titanium is reduced. The intensification of the process of sulfuric acid leaching by dividing the main stage of chemical dissolution of ilmenite into two stages was proposed. This method allows to leach up to 95.9% of titanium, which is 1.6–1.9 times higher in comparison with the classical technology of leaching altered ilmenite.


2011 ◽  
Vol 295-297 ◽  
pp. 543-546
Author(s):  
Jiao Jiao Wang ◽  
Chun Ying Han ◽  
Li Dan Zhang

In this paper, research was focused on the synthesis of a new efficient coagulant, boron -containing poly-silicate zinc (PSZB).The effect of the SiO2 concentration, Zn/Si molar ratio, B/Si molar ratio, activation time on flocculation properties were examined in detail. And the optimal preparation conditions were determined. At the same time, the industrial wastewater and life wastewater were treated for the properties test. The experimental results showed that the flocculant had good stability and good effect. It is a kind of good performance of flocculants.


2015 ◽  
Vol 3 (1) ◽  
pp. 53-56
Author(s):  
Кирил Безгласный ◽  
Kiril Bezglasnyy ◽  
Роман Скориков ◽  
Roman Skorikov ◽  
Артем Шаля ◽  
...  

This article shows the obstacles of using thermal power plant’s ash waste on an industrial scale. The results of determining the activity of fly ash and hydroremoval ash in a mixture with Portland cement are given. Schemes of translation ash from the category of waste with heterogeneous characteristics in the raw material with stable properties are offered. The most rational ways of using ash from thermal power plants in building materials are presented


2021 ◽  
Vol 321 ◽  
pp. 65-71
Author(s):  
Hoc Thang Nguyen ◽  
Phong Thanh Dang

Climate change is recognized as a global problem and even the industrial and construction sectors are trying to reduce the green-house gas emissions, especially on CO2 emissions. In Vietnam, the coal-fired thermal power plants are discharging millions of tons of CO2 and coal ash annually. This coal ash is comprised of about 80% of fly ash and the rest is bottom ash. This study would like to introduce one of the potential solutions in a carbon-constrained society that would not only manage the fly ash but also utilized this as raw material for green materials through geopolymerization. The geopolymer-based material has lower energy consumption, minimal CO2 emissions and lower production cost as it valorizes industrial waste. The fly ash containing high alumino-silicate resources from a coal-fired power plant in Vietnam was mixed with sodium silicate and sodium hydroxide solutions to obtain the geopolymeric pastes. The pastes were molded in 10x10x20cm molds and then cured at room temperature for 28 days. The 28-day geopolymer specimens were carried out to test for engineering properties such as compressive strength (MPa), volumetric weight (kg/m3), and water absorption (kg/m3). The microstructure analysis was also conducted for this eco-friendly materials using X ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Differential Thermal Analysis - Thermal Gravimetric Analysis (DTA-TGA).


2014 ◽  
Vol 937 ◽  
pp. 652-658
Author(s):  
Xin Hua Zhu ◽  
Zhao Zhang ◽  
Jun Shen

The silica, one of the by-products of fluorine industry, contains soluble fluoride which is harmful to the environment. Therefore, a study on fixing soluble fluoride was conducted by hydrothermal method with the silica as raw material and adding hydrated lime (HL), and the nanowires-reticulated calcium silicate with high specific surface area up to 143.8m2/g was prepared at the same time. The prepared calcium silicate was used as adsorbent in the experiments of phosphorus (P) adsorption from aqueous solution, the adsorption capacity, adsorption rate and P removability were characterized. The results show that the preparation conditions affect distinctly the adsorption performances of calcium silicate, especially, the dosage Ca/Si molar ratio. For the optimized calcium silicate sample, the total P adsorption capacity is 125.7mg/g and the exchange rate of Ca2+reaches 95.8%, the P residual concentration is only 0.3mg/L, the saturated adsorption time is 3900 min, when the simulation solution with P concentration of 100 mg/L is treated. The P residual concentration is only 0.1mg/L for the simulation solution of 56.12mg/L.


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