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.

Recovery of iron from lead-zinc metallurgical slags by bath smelting

The recovery of iron from iron sinking slag and lead smelter slag was investigated by desulfurization-reduction bath smelting. The effects of lead smelter slag(LSS) to iron sinking slag(ISS) mass ratio and temperature were investigated in desulfurization experiments. The X-ray diffraction(XRD) and X-ray fluorescence(XRF) analyses show that the optimum conditions are LSS:ISS of 3:7 and temperature of 1350°C. The composition of desulfurization products is mainly Zn Fe2O4, and the desulfurization rate of 99.66% is obtained under optimum conditions. The thermogravimetric(TG) and differential scanning calorimeter(DSC) analyses demonstrate that reductant is necessary for decomposition and reduction of zinc ferrite in desulfurization product. The effects of reductant, temperature and feeding modes on iron enrichment were investigated in reduction experiments. The scanning electron microscope(SEM) and energy dispersive spectrometer(EDS) determination show that the iron content of reduction product is up to 99.36% under optimum conditions of coke as reductant, reduction temperature of 1450°C and the feeding mode of premixing.

Thermodynamic Behavior of Manganese and Phosphorus between Liquid Iron and CaO-MgO-SiO_2-Al_2O_3-Fe_tO-MnO-P_2O_5 Slags

The thermodynamic behavior of manganese and phosphorus between liquid iron and CaO-MgO-SiO2-Al2O3-FetO-MnO-P2O5 ladle slag system was addressed by investigating the thermodynamic equilibria between liquid iron containing Mn and P and the ladle slag at 1873 K. The Mn distribution ratio L-Mn increases with increasing FetO content and decreasing the basicity ((%CaO + %MgO)/(%SiO2 + %Al2O3 + %P2O5)) in slag, while the P distribution ratio Lp seems to be increased as FetO content and the basicity increases. The values of L-Mn and L-p decrease by the addition of Al2O3 into slag. The expression of the dependence of L-Mn and L-p on the basicity and FetO content in slag was obtained.

A model for estimating the rate constant between CO_2-CO gas and molten slag containing iron oxides using optical basicity

A simple model for estimating the rate constant between CO2-CO gas and molten slag containing iron oxides was developed using optical basicity only. In this model, the temperature dependence of the rate constant can be described by the Arrhenius law, and the activation energy can be expressed with a linear function of the slag＇s optical basicity. The model was applied to some molten slag systems, such as FeO, FeO-CaO, FeO-SiO2, FeO-Na2O, FeO-CaO-SiO2, FeO-SiO2-P2O5, FeO-SiOE-Na2O, and FeO-CaO-SiOE-P2O5. A comparison between the predicted results and measured data showed that the model worked well.

Study on Foaming Behaviour of Molten Slag during Smelting Reduction with Iron Bath

The molten slag in smelting reduction with iron bath has peculiar behaviour for its high FeO concentration. Slag foaming is effected by the concentration and reduction rate of FeO, basicity of slag and temperature. Addition of granulated coke can greatly decrease slag foaming extent in the process of smelting reduction with iron bath. The anti-foaming capacity of granulated coke is the best when the ratio of coke used for coke layer to total coke used in smelting reduction is controlled at about 20%.

Distribution behavior of Copper and Tin between FeO-rich slag and iron solution

The distribution behavior of residual elements copper and tin between FeO rich slag and iron solution was investigated under the condition of an induction furnace. The results indicate that a part of copper and tin is incidently oxidized when oxygen is blasted into bath to react with iron element. The distribution ratio of copper and tin between slag and metal is about 0.1. Phenomena of Cu and Sn elements segregation and accumulation in slag were observed by means of EPMA analysis. The distribution ratio of copper and tin between slag and metal may descend with increasing of CaO content in slag.

Steel Slag as an Iron Fertilizer for Corn Growth and Soil Improvement in a Pot Experiment

The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. Slag alone or acidified slag was added to two Fe-deficient calcareous soils at different rates. Results showed that moderate rates (10 and 20 g kg-1) of slag or acidified slag substantially increased corn dry matter yield and Fe uptake. Application of steel slag increased the residual concentration of ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extractable Fe in the soils. The increase of extractable Fe was usually proportional to the application rate, and enhanced by the acidification of slag. Steel slag appeared to be a promising and inexpensive source of Fe to alleviate crop Fe chlorosis in Fe-deficient calcareous soils.

Corrosion of Magnesia-chrome Brick by Smelting Reduction Slag with Iron Bath

Effects of FeO content （0, 5%, 10%, and 15% in mass, respectively ） in lab-synthesized smelting redttc- tion slag with iron bath and test temperature （1 450, 1 500, 1550, anti 1 600 ℃ ） on corrosion am,amount and microstructure of fused rebonded magnesia - chrome brick with 26.02 massqc of Cr2O3 were researched by rotary cylinder method. The results show that ： （ 1 ） the corro- sion amolult of magnesia -chrome brick by slag without FeO is higher than that by the slag with 5% FeO, and the vorrosion amount increases when FeO content increa- ses from 5% to 15% ; （2） the test temperature is one of the important factors affecting the slag corrosion resist- ance of magnesia - chrome brick, and the corrosion of smelting reduction slag to brick increases with the temperature rising.

KINETICS OF REDUCTION IRON OXIDE IN CaO-SiO_2-Al_2O_3-Fe_tO SLAGS WITH CARBON SATURATED IN MOLTEN IRON

The rate of reducing Fet O in CaO-SiO2-Al2O3-Fet O slags with carbon saturated in molten iron has been determined in a graphite crucible in the temperature range of 1673-1773K. The effects of temperature, slag basicity and FetO content on the reduction rate have also been discussed. Test results show that the reduction rate increases with increasing temperature or FEtO concentration in slags, and the reduction rate has a parabolic relation with the simple basicity or optical basicity of slag, the maximum reduction rate being observed at around CaO/SiO2=1.5 of molten slags. The reduction reaction order is 1. 73 or 1.80, and the reduction activation energy is 299.9 or 295.9 kJ/mol in regard to Fet O weight content or Fet O activity calculated by using regular solution model, respectively. The reduction rate of CaO-SiO2-Al2 O3-Fet O slags with carbon saturated in molten iron is in the range of 0.32-3.48 mol-O/cm2·s.

基于炉缸渣铁滞留量的高炉炉缸活性研究

针对国内外对炉缸活性表征不明晰的问题,建立以炉缸渣铁滞留量表征炉缸活性的模型,定量分析高炉操作参数对炉缸活性的作用比重,并提出提高炉缸活性的操作手段。结果表明:①渣铁焦物性对渣铁滞留率的影响顺序为:铁水温度>CSR>焦炭粒度>CRI>炉渣碱度>镁铝比;②去除滞留率对滞留量的影响,高炉操作参数对渣铁滞留量的影响顺序为:风量>铁口深度>风温>风压>喷煤量>氧气量;③高炉生产中,可采用原燃料粒级及性能管控技术、高风速大动能操作技术、渣铁流动控制技术、渣铁排放管控技术高效调控炉缸活跃状态。

铁尾矿-矿渣基地聚合物的制备及其性能

我国铁尾矿产生量较高,但利用率仍较低,为了高附加值资源化利用铁尾矿,将铁尾矿、高炉矿渣与粉煤灰混合后作为硅铝原料,通过机械粉磨和碱性激发剂来激发其反应活性,制备地聚合物胶凝材料。探讨了高炉矿渣与铁尾矿的配比、碱激发剂水玻璃的掺量对地聚合物试样抗压强度的影响,分析了地聚合物胶凝材料形成机理。结果表明:将铁尾矿和高炉矿渣采用机械粉磨活化时,粉磨时间超过60 min后其比表面积提高幅度变小,综合考虑原料活性和成本,机械粉磨时间定为60 min。当粉煤灰掺量为10%、高炉矿渣与铁尾矿的配比为5∶3、碱性激发剂水玻璃掺量为10%时,所制得的地聚合物试样3、7、28 d龄期的抗压强度分别为10.7、18.9、32.9 MPa。地聚合物试样在养护过程中,随着养护时间的延长,试样的结构越来越致密,尤其是28 d龄期的试样结构更加致密,生成的凝胶产物填充在原料颗粒之间的空隙,并将未反应的原料颗粒包裹,与相邻的凝胶产物相互胶结,形成一整体,从而有利于试样抗压强度的提高。

三元固废掺和料耦合机理分析和活化

为实现铁尾矿固废材料的再生利用,提高工业固废利用率,利用陶瓷粉和钢渣组成三元固废掺和料(铁尾矿-陶瓷粉-钢渣)并耦合活化。通过对铁尾矿进行不同时间的机械研磨,加入不同活化剂进行化学活化来提高铁尾矿的活性。采用差热-热重(DTA-TG)分析、扫描电镜(SEM)等方法研究三元掺和料的耦合活化和机械-化学活化机理。结果表明,适当增加铁尾矿研磨时间可以提升掺和料体系的活性指数,Na2SiO3活化剂对掺和料体系活性提升最显著。在三元掺和料体系中,铁尾矿、陶瓷粉主要起填充作用,而钢渣中活性CaO、硅酸二钙(C2S)和硅酸三钙(C3S)成分可以参与水化反应生成较多水化产物,从而提升后期强度,复掺时活性指数均满足普通型Ⅱ级掺和料使用标准,最高活性指数可达88.29%,具备制备三元复合掺和料的潜力。

陕西韩城芝川古代冶铁遗址初步考察

韩城芝川古代冶铁遗址位于陕西省渭南市韩城芝川镇芝西村,遗存面积超4000 m^(2),考古年代为西汉。科研团队对该遗址开展冶金考古田野调查并采集到炉渣、陶片等遗物,使用扫描电镜及能谱(SEM-EDS)、金(矿)相显微观察等手段对采集到的18个冶炼遗物进行成分分析和显微结构观察。结果表明,16个炉渣为硅钙铝系高钙低铁炉渣,基体主要为玻璃相、偶见铁橄榄石,其产品是生铁,应为生铁冶炼炉渣。1个炉渣为高铁渣,以浮氏体为主、间有铁橄榄石和极少量玻璃相;1个样品的块状金属为熟铁,很可能为生铁炒钢的遗物。该遗址主要是生铁冶炼遗址,同时进行炒钢冶金活动,是迄今发现陕西渭南地区最早的生铁炒钢遗址。

河北平山战国冶铁遗址初步调查

平山战国冶铁遗址位于河北省石家庄市平山县北白家岸村西侧,面积约47000 m^(2)。2022年7月对该遗址进行田野调查并获取炉渣、炉壁等冶金遗存。采用X射线荧光光谱分析仪(EDX)、扫描电镜及能谱分析(SEM-EDX)、金(矿)相观察等科学试验方法,对10个炉渣等样品进行检测分析,结合炉渣的化学成分和显微组织讨论该遗址的冶炼性质与技术特征。结果表明,该遗址为冶铁遗址,技术类型为生铁冶炼,炼铁渣属于钙硅铝系高钙炉渣。

某氰化尾渣中磁选回收铁试验研究

为综合回收利用某含金银多金属氧化矿氰化尾渣中的铁,针对氰化尾渣进行了弱磁选和强磁选回收铁的试验研究。试验结果表明:在弱磁粗选磁场强度为238.85 kA/m,弱磁精选磁场强度为159.24 kA/m,弱磁粗选尾矿强磁选磁感应强度为1200 mT的条件下,通过弱磁—强磁分选工艺,获得了全铁品位为64.08%、铁回收率为21.11%的弱磁铁精矿和全铁品位为45.81%、铁回收率为40.31%的强磁铁精矿,综合全铁回收率为61.42%,达到了综合回收利用铁资源的目的。

联合容积絮凝法去除污水中磷的最佳投药量研究

实验研究了在不同磷浓度下铁盐、聚丙烯酰胺(PAM)和钢渣三者联合处理水中磷的方法。探索了在不同磷浓度下铁盐、聚丙烯酰胺(PAM)和钢渣三者联合容积絮凝处理水中磷的最佳投药量。在综合考虑各种情况下,原水磷浓度为8 mg/L时,三者联合容积絮凝最佳投加量为n(Fe)∶n(P)=2.5,PAM投加量为0.1 mg/L,钢渣投加量为4 g/L;原水磷浓度为4 mg/L时,三者联合容积絮凝最佳投加量为n(Fe)∶n(P)=3.5,PAM投加量为0.05 mg/L,钢渣投加量为3 g/L;原水磷浓度为2 mg/L时,三者联合容积絮凝最佳投加量为n(Fe)∶n(P)=2.5,PAM投加量为0.1 mg/L,钢渣投加量为3 g/L。最佳投药量下的出水磷浓度均满足《地表水环境质量标准》(GB3838-2002)Ⅲ标准。

铁浴条件下电炉粉尘球团的熔融与分离行为

为了提高对含锌电弧炉粉尘(EAFD)的利用效率,实验研究EAFD球团在铁浴条件下的还原熔化行为。定义铁液滴球形度作为判断其凝聚的标准,然后探讨铁液滴直径和球形度之间随时间变化的关系。根据实验最终建立EAFD颗粒的熔化和分离行为。结果表明,在铁浴条件下,EAFD球团的Zn去除率在5.0 min时达到99%以上,但在15.0 min时金属渣分离还没有完成。由于成分的波动,在EAFD球团中形成几个区域的液态渣,然后液态渣不断增加,直到球团完全熔化。球形度>65%、直径>500μm的Fe液滴的数量随着时间的推移而减少,大直径的Fe液滴先完成分离。渣铁分离过程如下:在布朗运动下Fe液滴在渣中形成,之后Fe液滴直径在马兰戈尼效应下增加,Fe液滴在渣中下降速度符合斯托克斯定律。

含砷铜渣中砷的分离与固化

砷是锌冶炼过程中的有害杂质元素,不仅制约着锌冶炼的顺利和安全生产,同时也影响企业的经济效益。云南某锌冶炼企业采用“SO_(2)还原浸出—铁粉沉铜”工艺处理锌冶炼浸出渣后所得铜砷渣砷含量高,为降低铜砷渣中砷的含量和提高铜渣的计价系数,采用“SO_(2)还原浸出—铁粉沉铜”工艺铁粉沉铜后的溶液为浸出剂,将含砷铜渣与含有一定浓度H_(2)SO_(4)及Fe^(2+)的铁粉沉铜后溶液以一定的液固比混合,用氧压浸出工艺进行处理,开展砷的分离与固化,深入研究关键技术参数对含砷铜渣中铜、砷浸出率,砷固化率以及固砷渣品质的影响规律。结果表明:含砷铜渣在初始硫酸浓度50 g/L、液固比5∶1、氧分压0.4 MPa、反应温度120℃、反应时间3 h的工艺条件下,可实现含砷铜渣中99%以上的铜和砷被浸出;含砷铜渣在铁砷质量比2.0、初始pH值1.0、液固比5∶1、氧分压0.4 MPa、反应温度120℃、反应时间3 h的固砷工艺条件下进行固砷处理,有价金属损失小,砷以稳定的臭葱石晶体固化,砷固化率98.23%,且臭葱石晶体结构良好、晶粒清晰、表面光滑、边缘整齐;固砷后的溶液经过锌粉置换沉铜,可产出含铜质量分数在70%以上的富铜渣,铜渣中铜的计价系数较除砷前提升13%,既实现了含砷铜渣中砷的分离与固化,降低了砷对环境的污染,又实现了企业的经济效益。研究结果可为锌冶炼含砷铜渣的高值化利用和砷的环境污染防治及环境风险防控提供参考。

山西翼城冶南汉代冶铁遗址初步调查

冶南遗址位于山西省临汾市翼城县冶南村,面积约1.2 km^(2),考古年代为西汉。采用X射线荧光分析仪(EDX)、扫描电镜及能谱分析仪(SEM-EDS)、金(矿)相显微镜等对冶南遗址采集的6个炉渣和2个金属铁块进行了基体成分和显微组织检测分析。结果表明,6个炉渣样品为硅钙铝系低铁渣;2个铁块样品为熟铁,可能是生铁炒钢产品。判断该遗址为生铁冶炼遗址,同时也是生铁炒钢遗址。该遗址是目前山西地区确认的第一处大型生铁冶炼及炒钢的汉代官铁遗址。