Extraction of aluminium and iron content from boiler slag by sintering
2006; Trans Tech Publications; Linguagem: Inglês
ISSN
2297-8941
Autores Tópico(s)Recycling and utilization of industrial and municipal waste in materials production
ResumoThe given paper is aimed at presenting the authors' research on a new way of recycling the vast quantities of boiler slag from thermal power plants or steel plants.As is known,large quantities of boiler slag take away farm fields and contaminate soil,groundwater as well as atmosphere.However,the slag contains rich aluminum.The sample of boiler slag used in our testing comes from Baotou Steel Plant,Inner Mongolia,China.For purpose,we have collected a 50 kg sample of the boiler slag,whose particle size distribution(PSD)and chemical content were tested repeatedly.In our testing,the PSD was derived by physically screening the samples by using a standard screens.The XRF analysis shows that the sample of boiler slag used in this test mainly contains 42.60% of SiO_2,32.60% Al_2O_3,2.43% Fe_2O_3,2.16% CaO,0.74% K_2O,0.44% MgO,0.16% Na_2O and 0.88% TiO_2 and some other trance elements.When the slag was pelletised with lime and fine coal,the pellets were sintered at about 1 000 ℃ for different times.After that,the sintered pellets were leached by euphoric acid to produce a solution with aluminum and iron.In our testing,aluminum extraction efficiency was as high as 86.50% while the sintered pellets(50% boiler slag∶ 40% fine coal∶ 10% lime)were leached with euphoric acid with an acid concentration of 4 mol·L-1 at solid to liquid ratio of 1∶5 at 80 ℃ for 24 h.At the same time,the iron extraction efficiency reached 94.60% under the same conditions with the Al maximum extraction efficiency highest.With the high yielding of aluminum and iron,the leached residue can also be taken as a material useful for highway construction or cement production.
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