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Resource Utilization Of Steel Spent Pickling Hydrochloric Acid Liquor: Study On The Preparation Of Nano-sized Iron Oxide By Electrochemistry Method

Posted on:2018-03-24Degree:MasterType:Thesis
Country:ChinaCandidate:J Z TangFull Text:PDF
GTID:2311330512467501Subject:Environmental Engineering
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Hydrochloric acid is widely used in steel production enterprises as the common pickling agent.A large amount of steel spent pickling hydrochloric acid liquor(SSPHAL)is generated each year in china,which has already been included in the domestic hazardous waste list.So far,the conventional disposal ways of SSPHAL are mainly to neutralize with lime milk,recycle hydrochloric acid by evaporation method and prepare iron series coagulants,which are not cost-effective in terms of resource utilization.In this paper,a special electrolysis testing apparatus is designed to investigate the treatment of SSPHAL by electrochemistry method,which aims to prepare high value-added nano-sized iron oxide with the iron ions in SSPHAL,and to improve the resource utilization efficiency of SSPHAL.A electrolytic apparatus was designed which is separated in two reaction chambers by cation exchange membrane with ruthenium-platinum titanium alloy as electrode.With electrolytic current from external DC power supply,electrolytic preparation of nano-sized iron oxide experiment was carried out with SSPHAL after filtration in anode chamber,and a certain concentration of NaCl solution and dispersant in cathode chamber.This paper uses sigle factor experiment to study the influence of dispersant type,current density,reaction temperature and calcination temperature on the preparation of nano-sized iron oxide,and optimizes the test conditions via the comparision of particle size,morphology and dispersion effect of product in TEM photo.Then,L9(34)orthogonal experiment is carried out with dispersant dosage,current density,reaction temperature and calcination temperature as the four factors and with product quality(g),Fe2O3 content(%),current efficiency(%),and particle size(nm)as the evaluation indicators to study the optimized testing conditions of preparing nano-sized iron oxide.Finally,the final nano-sized iron oxide product is prepared and represented during the optimized testing conditions.According to the results of sigle factor experiment,current density is determined in 80 A/m2.Relatively,adding polyethylene glycol separately has a better effect;reaction temperature and calcination temperature is determined in 20-30? and about 600?,respectively.As is shown in the orthogonal experiment,the significant influence factors of product quality,Fe2O3 content(%),current efficiency(%),and particle size are current density,reaction temperature,dispersant dosage and calcination temperature,respectively.As a result,a elliptical and short rod-like nano-sized iron oxide particles were prepared uder the optimized testing conditions,and its crystal form is determined as a-Fe2O3 by XRD;the average particle size and Fe2O3 content can reach 68nm and 99.53%,respectively,these two indicators can reach above the qualified product requirements of "Industrial Iron Oxide(HG/T2574-2009)",and the single index of Fe2O3 content can reach the class A requirement of iron oxide red pigment in "Iron Oxide Pigment(GB/T 1863-2008)";the current efficiency(%)and Fe recovery rate can reach 91.80%and 34.84%,respectively.
Keywords/Search Tags:steel spent pickling hydrochloric acid liquor, resourse utilization, electrochemistry method, nano-sized iron oxide
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