改性含钛高炉渣中金红石的选择性分离及浸出机理研究

含钛高炉渣的综合利用是冶金领域亟待解决的关键问题。针对该问题,以改性含钛高炉渣(含钛高炉渣在高温下经过氧化硅、压缩空气改性处理得到的炉渣)为原料,通过重选-碱浸-酸浸工艺来实现金红石晶体的选择性分离,获得高品质的人造金红石。具体研究各工艺参数对重选实验、碱浸实验、酸浸实验的影响。结果表明,较佳的工艺条件为:-150μm改性渣占比79.53%、冲程14 mm、冲次360 times/min;碱浸温度95℃、碱浸时间90 min、NaOH浓度3.0 mol/L;酸浸温度65℃、酸浸时间60 min和HCl浓度3.0 mol/L。产品金红石的TiO2含量为98.20%,MgO和CaO总含量为0.47%,是氯化钛白的优质原料。此外,通过电位-pH图明晰了碱浸-酸浸实验的浸出机理。

改性含钛高炉渣的盐酸加压浸出

经选择性富集的改性含钛高炉渣含TiO232%左右,是宝贵的钛资源。为此,采用盐酸加压浸出对改性含钛高炉渣提取其中的Ti进行了试验研究,并考察了盐酸浓度、反应时间、反应温度、矿酸比、物料粒度等因素对TiO2浸出率的影响。结果表明,在适宜的条件下,TiO2的浸出率可达到95%以上,所得钛液经水解获得的富钛料其TiO2含量大于95%,为改性含钛高炉渣加压浸出分离提供了技术依据。

表面改性对含钛炉渣光催化性能的影响

以攀钢含钛高炉废渣为原料,掺杂不同比例稀硫酸,采用高能球磨复合无机改性低温煅烧的方法,合成了具有钙钛矿型的表面改性含钛炉渣催化剂(SMTBBFS).用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(UV-Vis)和热重(TG)分析对SMTBBFS催化剂进行了表征,确定其具有钙钛矿结构;煅烧后出现明显团聚现象,粉体的颗粒形态均为不规则块状;在紫外-可见区域具有较强的光吸收能力.由Cr(Ⅵ)的光催化还原率来评价稀硫酸不同掺杂比例对SMTBBFS催化剂光催化活性的影响.结果表明:硫酸掺杂比例为2.5%时,SMTBBFS催化剂由于存在较高的CaTiO3/TiO2晶相比、吸附容量以及适宜的表面酸性,而具有较高的光催化活性.

改性高钛高炉渣的浮选性能

以攀钢高炉渣为原料,采用"选择性分离与长大"的方法使高炉渣中的钛富集于钙钛矿中,然后在常温25℃,pH值9.3下,研究捕收剂油酸、捕收剂A与抑制剂水玻璃、CMC的用量对改性高炉渣中钙钛矿浮选性能的影响.实验结果表明:捕收剂油酸和捕收剂A都能用于改性渣的浮选,但是捕收剂A浮选性能更佳;抑制剂水玻璃和CMC都能抑制脉石,但是水玻璃也抑制钙钛矿浮选,所以CMC更适用于改性高炉渣的浮选.本实验优化出最佳浮选工艺,即为捕收剂A用量600 g/t,CMC用量为1 500 g/t时,浮选效果最为理想.此选冶结合的绿色分离技术适宜于攀钢含钛高炉渣的综合处理.

改性炉渣处理低浓度含磷废水试验研究

[目的]探讨改性炉渣处理低浓度含磷废水的最佳工艺条件。[方法]利用盐酸改性的炉渣处理低浓度含磷废水,分析溶液p H、改性炉渣投加量、反应时间、温度等因素对除磷效果的影响,并对改性锅炉炉渣的除磷机理进行了初步探讨。[结果]当溶液p H为8,改性炉渣的投加量为2.0 g,反应时间为60 min,温度为35℃时,磷的去除率最高,达96.59%。[结论]该研究为低浓度含磷废水的处理提供了理论参考。

氢氧化钙改性炉渣处理甲基红废水试验研究

目的:探讨氢氧化钙改性炉渣处理甲基红废水的效果,为炉渣资源化利用和染料废水处理提供参考。方法:用氢氧化钙在高温下对炉渣进行改性,并考察溶液pH、甲基红初始浓度、处理时间、炉渣投加量等因素对改性炉渣处理甲基红染料废水的影响。结果:改性炉渣去除甲基红废水效果明显优于未改性炉渣;当甲基红初始浓度为20mg/L,pH为6,炉渣投加量4g,处理时间为40min的条件下,甲基红废水处理效率最高,达95.2%。结论:通过氢氧化钙对炉渣进行改性处理甲基红废水是可行的,为同类废水处理提供了较好的借鉴。

燃煤炉渣作为新型掺合料在预拌混凝土中的应用

燃煤炉渣的综合利用已得到一定的推广,但作为混凝土的新型矿物掺合料却处于初始研究阶段,实际应用仍然在摸索当中。由于燃煤炉渣成分复杂,使用前必须做好物化试验、矿物分析、有害元素鉴定等工作,以消除使用风险。原状灰渣本身存在缺陷,磨细后以掺合料掺入混凝土中对产品性能有影响,应对品质较差的炉底渣进行改性和混凝土配合比优化工作,这样能保证预拌混凝土的质量。

RH脱硫概述

为满足超低碳钢生产对低硫含量的要求,近年来开发了RH真空处理装置通过喷吹粉剂或在真空室添加脱硫剂脱硫的新方法.阐述了RH真空脱硫的主要方法以及RH真空脱硫工艺对脱硫剂的要求,分析了RH真空脱硫中的热力学和动力学问题,讨论了脱硫机理、脱硫渣系的选择及组成、电工钢转炉渣改性脱硫等问题,展望了RH脱硫工艺和脱硫剂研究发展趋势.

改性高炉渣对染料的吸附动力学及热力学研究

以高炉渣和壳聚糖为原料,制备了高温改性高炉渣-壳聚糖复合吸附剂(TBFSC)和盐酸改性高炉渣-壳聚糖复合吸附剂(ABFSC),考察了2种吸附剂对酸性蒽醌蓝和活性艳红K-2BP的吸附性能,研究了吸附过程的等温吸附特征、吸附动力学和热力学。结果表明,2种染料在TBFSC和ABFSC上的吸附更好地符合Langmuir等温方程,表观二级动力学模型能够很好地描述TBFSC和ABFSC的吸附动力学行为。对于染料在TBFSC上的吸附,粒子内扩散过程和液膜扩散过程是该吸附的速控步骤,而液膜扩散过程为ABFSC吸附染料的速控步骤。热力学参数表明,TBFSC和ABFSC对两种染料的吸附都是自发进行的物理吸附,吸附过程均无配位基交换、化学键等强的作用力。

Preparation of UV-visible light responsive photocatalyst from titania-bearing blast furnace slag modified with(NH_4)_2SO_4

Sulfate-modified titanium dioxide-bearing blast furnace slag（STBBFS） photocatalysts were prepared by the high energy ball milling method with（NH4）2SO4 and titanium dioxide-bearing blast furnace slag（TBBFS） as raw materials.X-ray photoelectron spectroscopy（XPS）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,thermogravimetric analysis（TGA）,UV-visible diffuse reflectance absorption spectra（UV-Vis）,adsorption experiment and photocatalytic degradation measurement were conducted to characterize the structure,surface status,light absorption capacity,adsorption capacity and photocatalytic activity of the obtained photocatalysts.The adsorption equilibrium was described by the Langmuir isotherm model with a maximum adsorption capacity of 8.25 mg/g of Cr（VI） ions onto the STBBFS photocatalysts.As a result,sulfation of TBBFS improved the photocatalytic activities of STBBFSx photocatalysts.At a low calcination temperature,the photocatalytic activity of STBBFS300 photocatalyst was markedly higher compared with TBBFSx prepared at high calcination temperature,indicating that the photocatalytic activity of STBBFSx photocatalyst was determined by the balanced result between adsorption capacity and perovskite content.

Preparation,characterization and photocatalytic activity of sulfuric acid-modified titanium-bearing blast furnace slag

The feasibility of reducing Cr(VI)from the aqueous solution by sulfuric acid-modified titanium-bearing blast furnace slag(SATBBFS)as a photocatalyst was investigated.The photocatalysts were examined by X-ray diffraction(XRD),UV-vis diffuse reflectance spectra,thermogravimetric analysis(TG)and Fourier transform infrared spectroscopy(FTIR).The photocatalytic activities of the different catalysts were evaluated by the photocatalytic reduction of Cr(VI)under UV-vis light irradiation.The results show that the photocatalytic activities of SATBBFS catalysts are strongly dependent on CaTiO3-to-TiO2 mass ratio,adsorption capacity and surface acidity,and SATBBFS calcined at 400°C shows a higher photocatalytic activity compared with other catalysts.

Recovery of Fe,V,and Ti in modified Ti-bearing blast furnace slag

A two-stage oxidation—alkali leaching—acid leaching method was proposed to recovery Fe,V,and Ti in modified Ti-bearing blast furnace slag.The optimal experiment conditions of iron extraction were one-stage oxidation time 40 s and holding time 8 min.The recovery rate of iron was 89.93%.The optimum experiment conditions of vanadium extraction were total oxidation time of 126 s,NaOH concentration of 4.0 mol/L,leaching temperature of 95℃,leaching time of 90 min,and the number of cycle was 4.The leaching rate of vanadium was 92.13%.The optimal experiment conditions of titanium extraction were HCl concentration of 4.5 mol/L,leaching temperature of 75℃,and leaching time of 90 min.The TiO_(2)content of synthetic rutile was 98.61%.

Effect of rutile crystal shapes on its settlement

The effect of rutile crystal shapes on its settlement in a modified slag was studied by theoretical analysis,FactSage simulation,X-ray diffraction and scanning electron microscopy.The results show that the settling velocities of spherical rutile crystals are faster than those of other shapes of rutile crystals under the same volume conditions,and the shape transformation of rutile crystals from rod to sphere can be achieved by adding titanium slag to Ti-bearing blast furnace slag.The volume fractions of the rutile crystals in the upper and lower parts of the modified slag are 30%and 71%when the added titanium slag increases to 278 g,indicating that rutile settling is obvious.Due to the rutile settling,half shaker sorting task is saved,and the recovery rate of TiO2 is significantly increased.The TiO2 content of rutile is greater than 93%,and the total content of CaO and MgO is less than 0.4%,meeting the requirements for the raw materials of titanium white in the chloride process.

RH处理过程钢液脱硫

为满足管线钢生产对低硫含量的要求 ,近年来开发了利用RH真空处理装置通过喷吹粉剂或在真空室添加脱硫剂脱硫的新方法。讨论了该方法的脱硫机理、脱硫剂的渣系选择及组成、转炉渣改性处理等问题 ,并结合国内外试验和生产情况 。