قائمة الطعام
Ball milling is a mechanical technique that is broadly used to grind powders into fine particles [134–141]. The reactants are generally broken apart using solvent molecules in the traditional method; but in ball milling, reactants are broken by using mechanical forces. The term mechanochemistry has been introduced very recently [142].
Analyzing the distributive characters of elements and dioxin congeners in fly ash, the method of washing-ball milling was utilized to remove chloride and degrade …
Current applications of ball milling will be covered in detail as well as its origin, recent developments and future scope, challenges and prospects. Chemical transformations covered include carbon-carbon and carbon-heteroatom bond formation, oxidation by solid oxidants, asymmetric organo-catalytic reactions, dehydrogenative …
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Due to the mechanical impact in ball milling resulting in local high temperature, a risk for dioxin formation might exist. Urakaev (Urakaev and Boldyrev 2000 ) estimated that the instantaneous (10 −8 –10 −9 s) local high temperature in ball mills could reach 1000 K because of collision impact and attrition.
Experiments were carried out in a practical-scale planetary ball mill holding three vessels (each capacity is 250L) contained steel balls. Figure 1 shows the schematic profile of the pilot-scale E-200 type system. ... Dioxin (Polluted soil and ash): The toxic equivalent of dioxins contained in the polluted soil was 7500 pg-TEQ/g, and that of ...
Peng et al. [12], [13] milled fly ashes directly, proved that metal components in the ashes is effective on dioxin degradation. Loiselle studied the mechanochemical reaction conditions of three different additives (CaH 2, ... Ball milling is found very effective for 2,4,6-TCP treatment and decomposition rate could be over 99.0% after 6 ...
In fact, high quantities of hydrogen halides and dioxin would form. In order to enabling such huge amount of plastic waste as viable feedstock for recycling, an investigation on mechanochemical pre-treatment by high energy ball milling is carried out on polypropylene containing decabromodiphenyl ether. Results demonstrate that co-milling with ...
Experimental tests of high energy ball milling with calcium oxide and silica were executed to assess its effectiveness to detoxify such fly ash. Mechanochemical treatment obtained 76% dioxins reduction in 4 h, but longer milling time induced a partial de novo formation of dioxins catalysed by copper. Nevertheless, after 12 h treatment the ...
The method is virtually universally applicable to solids, liquids or mixed solid-liquid phases and materials due to the intimate mixing and comminution process caused simultaneously by ball milling. Hence, a ball mill simultaneously serves as a mixing device and a reactor that mechanochemically activates and promotes the dehalogenation reaction ...
Degradation characteristics of dioxin in the fly ash by washing and ball-milling treatment. J Hazard Mater. 2017 Oct 5;339:191-199. doi: …
Ball milling of fly ash. An all-dimensional planetary ball mill (QXQM-2, Changsha Tencan Powder Technology Co., Ltd., China) was used for the MC treatment ... and in solid phase, a small decrease in Cl content was observed. Dioxin like PCB showed a gradual decrease in value with milling time in solid, while in gas-phase dechlorination …
Moreover, ball milling was stopped for 10 min every 30 min of working to release the heat. The typical ball-mill rotation speeds were 250, 300, 350, 400, 450 and 500 r.p.m.
Mechanical ball-milling is an effective technique to reduce particle size, increase lattice defects, and enhance the activity of materials. After mechanical ball-milling modification, an accelerated carbonation technology of municipal solid waste incineration fly ash (FA) was proposed. ... and the method provides a new idea for dioxin ...
The invention relates to the technical field of waste fly ash treatment, in particular to a treatment device for removing dioxin in incineration fly ash by using a ball mill. The flying ash incinerator comprises a ball milling device, wherein the ball milling device is used for forming a closed grinding chamber for flying ash, the flying ash is subjected to crushing …
At 400℃ for 90 min and 1% O 2, the dioxin removal rate was 95.80%, the detoxification rate was 91.73%, and the residual dioxin toxicity in MSWIFA was 22.7 ± 17.8 ng I-TEQ/kg, which was in line with the limit value of 50 ng I-TEQ/kg in the "Technical specification for pollution control of fly-ash from municipal solid waste incineration ...
During the first test, sample 1 (14 g of FA with a C 0 load of 4.44 WHO-TEQ ng·g −1) was submitted to ball milling. Unexpectedly, an increase to 5.76 WHO-TEQ ng·g −1 (+30% to the initial load) was observed ... Degradation characteristics of dioxin in the fly ash by washing and ball-milling treatment. Journal of Hazardous Materials, Volume ...
There are many types of ball mills, including stirring type, planetary type and horizontal type. Using zinc-potassium hydroxide-polyethylene glycol as a combined …
Washing and Fe/Ni-SiO2 ball-milling method seemed to be the best choice as the dioxin removal rate could reach up to 93.20%. Dioxin could be degraded to low …
Removal of carbon and dioxins from municipal solid waste incineration fly ash by ball milling and flotation methods. A ball milling pretreatment with additives for fly ash and …
High-intensity ball milling was applied to model fly ash (MFA) samples at 300 rpm (1 and 8 h) which were composed of silica, sodium chloride, activated carbon and doped with metal (0.2 wt.% Cu, Cr ...
There are many studies on photocatalytic degradation of dioxin-contaminated soil and liquids. Binh et al. (2014) mixed non-toxic solvents with nano-titanium anatase on the surface of 2 mm soil. ... Degradation characteristics of dioxin in the fly ash by washing and ball-milling treatment. Journal of Hazardous Materials, Volume 339, …
Comparison between the calculated kinetic constant of our model with the Pulverisette-4 ball mill and of the one obtained with previous work's data employing the QM-3SP2 mill [8] for the same pollutant (Table 4) indicates that their values are sensibly different (the average value estimated in this work K = 5.5901 × 10 −3 is 34% greater ...
Model dioxin compounds 4-chlorobiphenyl (4CB), octa-chlorodibenzo-p-dioxin (OCDD), and octachlorodibenzofuran (OCDF) were degraded by a mechanochemical (MC) process that involved milling with calcium oxide by use of a planetary ball mill. The degradation of 4CB produced mainly chloride ions and biph …
Dioxins. Article PDF Available. Dioxins reformation and destruction in secondary copper smelting fly ash under ball milling. March 2016. Scientific Reports 6 (1):22925. DOI:...
To promote the degradation of dioxin, CaO, SiO 2, and iron powder. are often used as additives during the disposal of fly ash. Lu et al. studied the mechano-chemical mechanism of the degradation of 2,4,6-trichlorophenol via ball milling by adding CaO and SiO 2 to 2,4,6-trichlorophenol. The reaction mechanism of a four-step pathway …
Experimental tests of high energy ball milling with calcium oxide and silica were executed to assess its effectiveness to detoxify such fly ash. Mechanochemical …
2 ball-milling method seemed to be the best choice as the dioxin removal rate could reach up to 93.20%. Dioxin could be degraded to low toxic compounds and heterochorides with Fe/Ni as dechlorinating agent. In the process, PCDFs were partly transformed to PCDDs, while too long time of ball-milling was not benefited for dioxin removing.
Due to the reaction in the extremely enclosed high-energy ball mill tank, there is no gas pollution. There are many types of ball mills, including stirring type, planetary type and horizontal type. ... Qiu et al. (2019) achieved the goal of dioxin degradation and heavy metal stabilization by microwave-assisted hydrothermal process. …
Dioxin degradation is considered essential for the environmentally sound management of municipal solid waste incineration fly ash (MSWIFA). ... FA typically requires pretreatment steps similar to traditional ceramic processing, including washing, sieving, ball milling, drying, compaction, and pelletizing ...
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