Co-pyrolysis of soybean soapstock with iron slag/aluminum scrap,and characterization and analysis of their products

Soybean soapstock(SS) is one of the main solid wastes produced in the refinery of edible oil processing. In this study, the co-pyrolysis of SS with iron slag(IS) and aluminum scrap(AS) was carried out in a tubular furnace. The gas, liquid and solid products were characterized and the char yield decreased with increasing IS/AS ratio. IS and AS can improve the gas yield, and when the ratio of SS/IS was 1:0.25, the total pyrolysis gas and hydrogen contents were significantly increased. The content of oxygen compounds in pyrolysis oil decreased during co-pyrolysis, while AS promoted the content of polycyclic aromatic hydrocarbons in pyrolysis oil. The co-pyrolysis reaction can be divided into four stages, the mass loss rate reaches the maximum at the third stage(390–575 ℃). The molar ratio of H/C was lower for pyrolysis,indicating good stability of pyrolysis char owing to the high degree of carbonization and aromaticity.The possible co-pyrolysis reaction mechanism was explored.

Preparation of Nano-Alumina with Aluminum Scraps as Raw Materials

Ammonium aluminum carbonate hydroxide (AACH) was synthesized by the reaction of ammonium aluminum sulphate (AA) with ammonium hydrogen carbonate (AHC). AA was obtained by the reaction of NH4HSO4 with aluminum scraps as the raw materials. According to this method, AACH samples prepared were used to fabricate nano alumina powders by thermal decomposition. The microstructural properties of as-formed alumina were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), special surface analysis and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Experimental observations revealed that highly pure (99.99%) α-alumina with mean diameter of 49 nm could be obtained.

Recycling of waste aluminum scraps to fabricate sulfidated zero-valent iron-aluminum particles for enhanced chromate removal

Massive waste aluminum scraps produced from the spent aluminum products have high electron capacity and can be recycled as an attractive alternative to materials based on zerovalent iron(Fe^(0))for the removal of oxidative contaminants from wastewater.This study thus proposed an approach to fabricate micron-sized sulfidated zero-valent iron-aluminum particles(S-Al^(0)@Fe^(0))with high reactivity,electron selectivity and capacity using recycled waste aluminum scraps.S-Al^(0)@Fe^(0)with a three-layer structure contained zero-valent aluminum(Al^(0))core,Fe^(0) middle layer and iron sulfide(FeS)shell.The rates of chromate(Cr(Ⅵ))removal by S-Al^(0)@Fe^(0)at pH 5.0-9.0 were 1.6-5.9 times greater than that by sulfidated zero-valent iron(S-Fe^(0)).The Cr(Ⅵ)removal capacity of S-Al^(0)@Fe^(0)was 8.2-,11.3-and 46.9-fold greater than those of S-Fe0,zero-valent iron-aluminum(Al^(0)-Fe^(0))and Fe^(0),respectively.The chemical cost of S-Al^(0)@Fe^(0) for the equivalent Cr(Ⅵ)removal was 78.5%lower than that of S-Fe^(0).Negligible release of soluble aluminum during the Cr(Ⅵ)removal was observed.The significant enhancement in the reactivity and capacity of S-Al^(0)@Fe^(0)was partially ascribed to the higher reactivity and electron density of the Al0core than Fe^(0).More importantly,S-Al^(0)@Fe^(0) served as an electric cell to harness the persistent and selective electron transfer from the Al^(0)-Fe^(0) core to Cr(Ⅵ)at the surface via coupling Fe^(0)-Fe^(2+)-Fe^(3+)redox cycles,resulting in a higher electron utilization efficiency.Therefore,S-Al^(0)@Fe^(0) fabricated using recycled waste aluminum scraps can be a cost-effective and environmentally-friendly alternative to S-Fe^(0) for the enhanced removal of oxidative contaminants in industrial wastewater.

Selective catalytic reduction of NO by NH3 on cerium modified faujasite zeolite prepared from aluminum scraps and industrial metasilicate

This work was devoted to the study of the selective catalytic reduction of NO by NH3 on calcined and hydrothermal treated cerium loaded zeolite catalysts.The parent faujasite zeolite Na-F(Si/Al=1.32 and SBET=749 m^2/g) used as support for the preparation of the catalysts was obtained from industrial sodium metasilicate and aluminum scraps.As expected,the NO conversion increases with increasing the percentage of cerium in the structure of the faujasite zeolite.Total NO conversion into N2 is reached at 400℃at a space velocity of 250 000 h^-1.The high conversion is due to the redox shift between Ce^3+/Ce^4+and the strong acid sites related to the rare earth present in the framework that is the key in SCR of NO process.Moreover,the highest loaded cerium catalyst retains almost its activity after hydrothermal treatment at 850℃.This higher loading is desirable for both activity and stability provided that two stages of preparation are used to put the Ce ions in the sodalite cages.

Purification of scrap aluminum foil and aluminum melt covering and protecting & atomic purification theory

A new flux, JDN I, including rare earth compounds, for purification of the scraps of 99.99% aluminum foil was introduced. The experimental results indicate that its function of degassing and deoxidizing is excellent. The hydrogen content of the scrap aluminum foil melt purified by JDN I flux decreases greatly from 4.5 mL/kg to 1.2 mL/kg at 720 ℃. The tensile strength of the samples refined with JDN I flux increases by 19.2% and the elongation increases by 38.3% in comparison with those without flux. The purification mechanism of JDN I was discussed and a theory of covering, protecting & atomic purification was also put forward.

鱼雷罐内加废钢对耐材影响分析

对某钢厂25#鱼雷罐的耐材渣样进行分析,结果表明:25#鱼雷罐罐内残留渣成分与高炉渣成分相差较大,尤其MnO含量较高。通过扫描电镜分析可知,MnO、CaO等对铝碳化硅炭砖的骨料和基质熔损较大。25#鱼雷罐锥体出坑与此罐运转过程中,罐内局部渣铁成分发生巨大变化,其对铝碳化硅炭砖熔损较快,导致局部出坑。

Direct oxygen removal from titanium aluminide scraps by yttrium reduction

Titanium aluminum(TiAl)scraps with a high oxygen content were treated with yttrium(Y)in a liquid chemical deoxidization process for recycling.The Gibbs free energy and the equilibrium constant of the deoxidization reaction were calculated,and the effects of the yttrium content and the system pressure on the oxygen content in the product were determined.The results showed that the oxygen in TiAl scraps could be removed by yttrium,and the oxygen content of the deoxidized TiAl scraps had only 10%of the original content after deoxidization.Furthermore,the oxygen content of the deoxidized TiAl scraps was decreased with the increase of yttrium addition.The higher the chamber pressure,the greater the oxygen content in the final TiAl alloys.These results were consistent with calculated values.The microstructure of the deoxidized alloys was akin to that of the original material;however,Y_(2)O_(3) particles were observed in the deoxidized alloys.

废铝回收再利用的研究现状

铝及铝合金的抗腐蚀性强,在使用过程中损耗程度极低,具有极高的再生利用价值,促进废铝回收可显著降低铝行业的能耗和碳排放。本论文主要对废铝的重熔降级回收、保级回收及越级回收工艺进行了总结,对各工艺的优缺点进行分析。采用传统的废铝重熔降级再生工艺无法完全去除铝中的合金元素与金属杂质,再生铝只能降级利用,但随着再生铝量的增加,传统的降级利用技术将无法消纳过量再生铝。保级回收可实现废铝资源价值最大化,但是只有极少量的优质废旧铝合金能实现其固有价值,大部分废铝资源难以实现。废铝越级回收技术能够将铝合金中铝与合金元素进行有效分离,使回收的铝达到原铝的质量水平,可实现废铝的彻底再生,是废铝再生的最佳途径之一。熔盐电解法是最具发展前景的废铝提铝再生技术。

铝合金压铸件切边废料回收熔融装置研究

针对铝合金压铸件切边废料高效回收利用难的问题,对熔融装置进行设计和优化,能达成废料高效熔融和质量控制的目的。这需要利用结构创新和技术提升明显提高熔融效率,保障操作安全。试验数据证明,优化熔融装置能显著提高废料回收率,对铝合金压铸行业绿色生产具有强大的技术支撑。熔融装置应用于铝合金压铸行业的巨大潜力,能对该产业的可持续发展起到积极的推动作用。

用废铝渣制备聚合硫酸铝

将铝材厂前处理过程产生的废铝渣用硫酸溶解,然后加入有机添加剂等进行聚合反应,制备新型水处理剂———聚合硫酸铝(PAS)。用PAS与聚合氯化铝(PAC)进行絮凝对比实验,结果表明,对于硅藻土浊度水、水源水和工业废水等,PAS比PAC具有更优异的除浊、脱色、去除COD和悬浮物的效果。该工艺既可回收利用废铝渣,又可省去废渣处置费用,为废铝渣的综合利用提供了实用技术。

中国铝的社会蓄积量及折旧再生指数分析

我国近些年来原铝产量和消费量快速增长,铝土矿资源严重不足,在很大程度上依赖于进口.随着铝社会蓄积量的增大,废铝资源将越来越多,并在铝工业中发挥更大的作用.通过对我国铝的社会蓄积量及其平均年龄、回收率、折旧再生指数等进行分析,得到以下结果：1990年~2010年铝的社会蓄积量从723万 t 增长到10355万 t；2010年铝制品的平均年龄约为4.3年,折旧再生指数和铝的社会蓄积量回收率分别为0.0747 t /t和1.17%.基于未来铝消费的3种情景进行了分析,在情景3下：预计我国铝的社会蓄积量在2035年达到最大值6亿 t,2055年稳定在5.7亿 t；铝制品平均年龄在2040年达到最大值（7.13年）,同年折旧再生指数达到最大值（0.79 t/t）,铝的社会蓄积量回收率也达到最大值（5.05%）.研究结果将为铝工业相关政策的制定提供一定的参考.

深冷处理对废铝易拉罐合金组织和力学性能的影响

在液氮温度下对废铝易拉罐合金作了48 h的深冷处理,并进行了金相组织分析和力学性能测试。结果表明,深冷处理显著提高了合金的力学性能,抗拉强度和伸长率分别提高了10.7%和36.2%。

电解铝残阳极清理局部排风罩气流场的数值模拟

目的分析电解铝残阳极清理工艺中采用带有可调节挡板的下吸式排风罩的气流特性,以达到除尘节能的目的.方法采用CFD数值模拟方法,使用FLUENT软件,以三维物理模型作为计算基础,对残阳极清理工艺过程中下吸式排风罩气流场进行模拟.结果挡板夹角α的变化对气流场及控制点的风速有较大地影响,在挡板角α为30°时的排风速度最小(vp=2.92 m/s),较无挡板的下吸罩节约排风量44.38%.结论在电解铝残阳极清理工艺中,与同规格无挡板下吸罩相比,采用带有可调节挡板的下吸式排风罩对残阳极上部的流场分布有明显的改进,在达到同样的控制风速下,排风量有较大地降低,节能效果显著.

废铝旋转喷吹除氢的水模拟试验与熔炼实验验证

为探索废铝熔体旋转喷吹除氢的优化工艺组合,从氢的来源入手,以相似原理为指导,进行旋转喷吹的水模拟试验,然后以水模拟试验结果为参考,进行废铝的熔炼除氢实验,并分析其除氢效果。结果表明:转子偏置分布实验中,氢的质量浓度从0.30 mL/100 g降至0.11 mL/100 g,效果明显优于转子中心分布实验,从而验证水模拟试验的优化工艺组合的准确性。

两段沉淀法净化某废旧高温合金浸出液的研究

采用两段沉淀法净化某废旧高温合金浸出液,第一段采用质量分数为15%的磷酸钠溶液作为沉淀剂,机械搅拌条件下,控制终点pH 2.5,温度70℃,反应时间2h,铬、铝的除杂率均在90%以上;第二段采用质量分数为15%的氢氧化钠溶液作为沉淀剂,机械搅拌条件下,控制终点pH 5.5,温度70℃,反应时间2h,铬、铝的脱除率均在99%以上,所得净化液可直接进行下一步镍钴分离处理,扩大试验结果表明,此工艺有良好的工业应用前景。

铝屑制备聚合铝的净水效果

采用由铝屑制备的聚合铝,其净水效果表明,当它的盐基度在64%时,处理效果最佳;它的混凝效果要优于其它铝盐混凝剂,它与助凝剂改性活化硅酸共同使用可获得非常显著的处理效果.

干法球磨从废铝边角料中制取片状铝粉工艺研究

对在氮气惰性气氛下,利用废弃铝边角料生产片状铝粉的可行性进行了研究。发现在球磨过程中,废铝片通过钢球的微锻作用相互挤压分层,延展,细碎,最后形成片状铝粉,球罐中的钢球球径大小与片状铝粉的产出性能有着重要的关系,球径大的钢球研磨对铝粉的形成更有利;在球磨的前25h,适当次数的间歇停机冷却球罐可以提高铝粉的细度;硬脂酸的加入可以减少铝粉与铝粉,铝粉与钢球或罐壁的摩擦,降低球磨效率,加入3%的硬脂酸作为助磨剂球磨效果最佳。所得片状铝粉可用于指纹鉴定、加气节能混凝土等。

PAFC的制备及其在酸性红73废水处理中的应用

以钢铁镀件前处理产生的酸洗废液和工业废铝为原料,采用氧化聚合法制备聚合氯化铝铁（PAFC）絮凝剂,并用PAFC处理低浓度的酸性红73,考察各因素对去除效果的影响。实验结果表明：在最佳条件下,PAFC处理10 mg/L的酸性红73的去除率高于85%,处理效果优于市售PAC,但与市售PAFC相当;铝铁比为9∶1的PAFC处理5~20 mg/L的酸性红73,其上清液出水色度均达到了《纺织染整工业水污染物排放标准》（GB 4287—2012）中的特别排放限值要求;达到了以废治废的目的。

废杂铝熔化再生工序的能耗模型

随着对工业节能和环保要求的不断提高,废杂铝回收和再生过程的能效研究受到了广泛关注.分析了在熔化工序中各主要因素对能耗的影响,建立了废杂铝熔铸过程熔化工序的能耗理论模型.以燃气炉为主要熔炼设备,将熔化工部能耗分为目标物料耗能、均匀化搅拌耗能和其他形式耗能,并分别建立了他们的定量计算公式.通过对比批式单体炉和连续双室炉的设备和工艺差异,分析了主要影响因素对二者能耗的影响程度和趋势,发现双室炉较单体炉具有10%以上的节能能力.

以废酸、废碱液制备聚合氯化铁铝的实验研究

以钢厂含铁废酸和铝加工业含铝废碱及废铁屑为原料制备聚合氯化铁铝(PFAC)。实验研究了废铁屑加入量等因素对Fe2+溶出率的影响,同时研究了Fe2+的氧化条件。结果表明,在25℃、反应时间为15～20 min、氧化剂氯酸钠加入量等于化学计量值时,Fe2+氧化率可达98.7%以上。用废碱液调整盐基度,PFAC盐基度为20%时,对活性蓝P-3R水溶液的A590去除率可达99.8%;并对PFAC样品进行了红外光谱表征。