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.

Simultaneous preparation of TiO2 and ammonium alum,and microporous SiO2 during the mineral carbonation of titanium-bearing blast furnace slag

In this study,a route for simultaneous mineralization of CO2 and production of titanium dioxide and ammonium alum,and microporous silicon dioxide from titanium-bearing blast furnace slag(TBBF slag)was proposed,which is comprised of(NH4)2 S04 roasting,acid leaching,ammonium alum crystallization,silicic acid flocculation and Ti hydrolysis.The effects of relevant process parameters were systematically investigated.The re sults showed that under the optimal roasting and leaching conditions about 85%of titanium and 84.6%of aluminum could be extracted while only 30%of silicon entered the leachate.84%of Al^3+was crystallized from the leachate in the form of ammonium aluminum sulfate dodecahydrate with a purity up to 99.5 wt%.About 85%of the soluble silicic acid was flocculated with the aid of secondary alcohol polyoxyethylene ether 9(AEO-9)to yield a microporous SiO2 material(97.4 wt%)from the crystallized mother liquor.The Al-and Si-depleted solution was then hydrolyzed to generate a titanium dioxide(99.1 wt%)with uniform particle size distribution.It was figured out that approximately 146 kg TiO2 could be produced from 1000 kg of TBBF slag.Therefore,the improved process is a promising method for industrial application.

Recent progress of efficient utilization of titanium-bearing blast furnace slag

Titanium-bearing blast furnace slag(BFS)has valuable compositions and potential environmental hazardousness.Thus,developing efficient and green approaches to utilize BFS is highly desired for resource economization and environmental protection.In the past decades,many attempts have been adopted to reuse BFS efficiently,and significant advances in understanding the fundamental features and the development of efficient approaches have been achieved.This review provides a comprehensive overview of the latest progress on the efficient utilization of BFS and discusses the mechanism and characteristics of various approaches,along with their application prospects.In particular,the extraction and enrichment of titanium-bearing phases from BFS are highlighted because of the high availability of titanium resources.This systemic and comprehensive review may benefit the design of new and green utilization routes with high efficiency and low cost.

Recovery of titanium,aluminum,magnesium and separating silicon from titanium-bearing blast furnace slag by sulfuric acid curing-leaching

An energy-efficient route was adopted to treat titanium-bearing blast furnace slag(TBBFS)in this study.Titanium,aluminum,and magnesium were simultaneously extracted and silicon was separated by low temperature sulfuric acid curing and low concentration sulfuric acid leaching.The process parameters of sulfuric acid curing TBBFS were systematically studied.Under the optimal conditions,the recovery of titanium,aluminum,and magnesium reached 85.96%,81.17%,and 93.82%,respectively.The rapid leaching model was used to limit the dissolution and polymerization of silicon,and the dissolution of silicon was only 3.18%.The mechanism of sulfuric acid curing-leaching was investigated.During the curing process,the reaction occurred rapidly and released heat massively.Under the attack of hydrogen ions,the structure of TBBFS was destroyed,silicate was depolymerized to form filterable silica,and titanium,magnesium,aluminum,and calcium ions were replaced to form sulfates and enriched on the surface of silica particles.Titanium,aluminum,and magnesium were recovered in the leaching solution,and calcium sulfate and silica were enriched in the residue after leaching.This method could effectively avoid the formation of silica sol during the leaching process and accelerate the solid-liquid separation.

Antibacterial Properties of V-doped Titanium-bearing Blast Furnace Slag Prepared at Different Calcination Temperatures

Perovskite-type V-doped titanium-bearing blast furnace slag (VTBBFS) photocatalyst was prepared by high-temperature solid phase method.The influence of calcination temperature on the photocatalytic and antibacterial properties of VTBBFS was studied in details.Its composition and microstructure were evaluated by X-ray diffractometer,ultraviolet-visible absorption spectrometer,Fourier transform infrared spectrometer and scanning electron microscope.The antibacterial properties of VTBBFS to Candida albicans were investigated by flask oscillation method.The results showed that the optical absorption and antibacterial properties of VTBBFS were the best with 10%(ω) doping of vanadium,prepared at 800℃ for 2 h,and its sterilization rate was close to 100% to Candida albicans (ATCC10231).The minimum inhibitory and minimum bactericidal concentrations were 25 and 50 mg/mL.When the concentration was 0.2 μg/mL,the catalyst had the least toxic toxicity.

Synthesis of Foliar Fertilizer and Ca-S-Si Compound Fertilizer from Titanium-bearing Blast Furnace Slag

With titanium-bearing blast furnace slag, ammonium sulfate, citric acid and potassium carbonate as raw materials to produce foliar fertilizer and Ca-S-Si compound fertilizer by means of heating process for the first time, which improved the solubility of the slag and converted the nutritional elements into such ones which are prone to be absorbed by plants. The effects of process conditions on dissolution rate of titanium were mainly analyzed through the orthogonal experiment. The results showed that the optimum synthesis process conditions of foliar fertilizer from the slag were 360 ℃ for 35 min, the mass ratio of ammonium sulfate and titanium-bearing blast furnace slag was 8：1. Under these conditions more than 80% of iron, titanium, magnesium and part of silicon in titanium-bearing blast furnace slag converted into water-soluble substances and existing in foliar fertilizer. Foliar fertilizer contained nitrogen, sulfur, potassium, iron, titanium, magnesium and silicon, and pH value of foliar fertilizer was 6. Ca-S-Si compound fertilizer mainly contained calcium silicate and calcium sulfate, which existed in the form of citric acid-soluble substance and slightly soluble substance, respectively.

Determination of dielectric properties of titanium carbide fabricated by microwave synthesis with Ti-bearing blast furnace slag

The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery;it can alleviate the environmental pressure caused by slag stocking.The dynamic dielectric parameters of Ti-bearing blast furnace slag/pulverized coal mixture under high-temperature heating are measured by the cylindrical resonant cavity perturbation method.Combining the transient dipole and large π bond delocalization polarization phenomena, the interaction mechanism of the microwave macroscopic non-thermal effect on the titanium carbide synthesis reaction was revealed.The material thickness range during microwave heating was optimized by the joint analysis of penetration depth and reflection loss, which is of great significance to the design of the microwave reactor for the carbothermal reduction of Ti-bearing blast furnace slag.

高炉渣矿棉的研究现状及发展趋势

高炉渣矿棉因其轻质、不燃、防霉等诸多优良的性能而在节能环保、隔音降噪等方面发挥着重要作用。本文综述了高炉渣矿棉的特点、用途、生产工艺及关键技术,分析了影响高炉渣矿棉性能的诸多因素,并对新近提出的高炉熔渣直接生产矿棉技术应用中存在的潜在问题进行了评述和展望。高炉熔渣直接生产矿棉技术无论是对目前存在的能源危机或环境问题,还是对保温隔热材料行业的发展或钢铁行业的节能减排都具有十分重要的意义。

提高钛硅合金等级的研究

在采用硅铝铁作还原剂冶炼钛硅合金的实验中，研究了冶炼温度、炉料初始碱度、还原剂用量等因素对钛硅合金中钛、硅含量、残渣中ＴｉＯ２含量、钛回收率的影响，获得了升钛降硅的最佳工艺参数。利用实验获得的最佳工艺参数进行了实验室稳定试验和半工业性稳定试验。

三种不同镍渣混合生产复合掺合料的研究

研究了RKEF法镍铁不锈钢一体化生产线产生的高炉镍铁渣、电炉镍铁渣、不锈钢精炼混合渣的粉磨特性、用作掺合料对胶砂流动度、活性指数的影响,在此基础上通过复掺混合粉磨制备复合掺合料,以期实现不锈钢精炼混合渣的利用。结果表明,当配合比为精炼渣:电炉渣:高炉渣为4:3:3时,制备的复合掺合料性能最佳,其胶砂流动度比为103%,7 d活性指数为81%,28 d活性指数为88%,可达到行业标准JG/T486中普通型Ⅱ级复合掺合料的技术要求。

含钛炉渣综合利用技术研究进展

对含钛炉渣综合利用技术进行了叙述,着重综述了高炉钛渣和电炉钛渣综合利用技术国内外的研究进展,并指出了两类钛渣综合利用技术研究的方向。

利用高炉矿渣生产微晶玻璃的研究应用

莱钢每年排放大量的高炉矿渣造成了严重的环境污染，利用高炉矿渣生产微晶玻璃受到国内外的广泛关注。本文简要介绍了目前利用高炉矿渣生产微晶玻璃的基本原理和生产工艺，并简单分析了该项目的投资与经济效益，以及产品的应用前景等。认为高炉矿渣生产微晶玻璃是一项很有前景的材料开发和资源综合利用项目。

高炉冲渣水系统变频技术改造的实施和评价

变频调速技术是一项高效节能技术。本文通过工程改造实例,详细介绍炼铁高炉冲渣水系统变频技术改造的情况。从技术上分析,满足其安全可靠的生产工艺要求;从改造前后的数据统计分析,这项改造对节约能源,特别是电能,具有重要的现实意义。

高炉渣回收利用的专利技术现状

专利是市场经济的产物,专利技术往往代表本行业的技术发展水平与发展方向。文章主要从中国专利的角度分析高炉渣回收利用技术的研究现状。笔者在中国专利检索系统数据库进行了全面的检索,对得到的检索结果进行细致的筛选分类,并作了深入的研究分析。还重点介绍了若干个较新的专利技术,以期对从事相关领域的企业、科研单位和个人提供参考。

高炉煤气流综合诊控技术研究及应用(下篇)

深入研究了高炉冶炼过程中包括煤气流的在线诊断、量化评价、参数优化等内容的综合诊控技术,并应用于生产实践。结果表明,在入炉品位升高0.44%、渣量下降13.7 kg/t条件下,边缘煤气发展指数下降0.02,中心煤气发展指数上升0.02,煤气利用率提高0.59%,燃料比下降9.50 kg/t。该精准化、标准化的技术在高炉日常操作实践中的持续应用,达到了适时优化煤气流分布、改善高炉顺行和冶炼技术指标的目的,说明该技术具有良好的适应性和经济性。

硫酸酸解钙钛矿相精矿的行为

攀钢每年排放含TiO_(2)(20%~25%)的高炉渣300万吨,大量的高炉渣占用土地、引起灰尘污染,形成危害。为解决攀钢含钛高炉渣的利用问题,本文采用“选择性析出”技术,即在高炉排出高炉渣后加入保温措施使炉渣缓慢冷却,将钛组分富集到钙钛矿相中,晶粒长大,进一步选矿分离,可得到含TiO_(2)35%~50%的精矿。进一步对得到的以钙钛矿为主的含钛精矿进行了硫酸酸解的实验研究。研究表明酸解精矿的最优条件是使用小于76μm的精矿、90%的H_(2)SO_(4),精矿和硫酸质量比为1∶1.21,180℃温度反应4h,在该条件下钛元素酸解率达到94.62%。酸解动力学实验表明,在精矿酸解反应初始阶段(x=0~0.3),化学反应动力学为主要特征;中间阶段(x=0.5~0.7)为化学反应和内扩散混合控速;酸解反应进入后期(x>0.7)为内扩散控速步骤。

炉渣轮法粒化装置在太钢四高炉上的应用

太钢四高炉扩容改造大修工程引进一种新型的炉渣处理装置轮法化装置。和传统的炉渣处理方法如INBA法、底滤法、沉淀池法相比,工艺先进,运行可靠,达到国际上该领域的先进水平。

高炉渣显热回收利用现状与展望

高炉渣是炼铁过程中生产的副产品,也是工业生产的废弃物。随着钢铁企业的快速发展,高炉渣的排放量也日益增多。相比国外某些发达国家,我国高炉渣的利用率相对较低。高炉渣的堆放不仅浪费土地资源,还严重污染着环境,与我国现行的可持续发展计划相悖。但是如果将其经过回收和利用,便可以成为很好的矿物资源。与此同时,高炉渣也含有大量的显热。我国传统的水淬法对熔渣显热没有任何回收利用,白白地散失了大量的热量。针对这种情况,国内外科研人员进行多次的实验,主要可以分为两个方向:物理换热法和化学回收法。物理换热法主要是高炉渣通过特定的能量载体进行收集实现显热回收化学回收法是直接利用熔渣及显热生产高附加值的产品。与前者相比,化学回收法对显热的回收更有效率,更能体现高炉渣的综合利用。本文详细地综述了物理法和化学法显热回收,并分析了各种方法的优缺点。在此基础上,作者开发了新的回收方式:高炉渣干法粒化技术,这是高炉渣处理的发展趋势。

高炉熔渣高值资源化的现状及展望

高炉熔渣是高炉冶炼过程中排出的废渣,是能够回收利用的非常优质的资源。其显著特点,一是价格低廉;二是堆存易造成环境污染;三是高附加值产物有较高的应用前景。本文首先概述了高炉渣的处理现状,之后对其高附加值产物,即玻璃微珠的制备工艺进行介绍,文章最后指明高炉渣与高性能玻璃微珠之间存在着相关性,且制备过程存在空心玻璃微珠,性能有待进一步探究。

高炉冲渣水余热回收的利用技术分析

在整个热工的环保工程当中,高炉冲渣水的余热主要有三种利用途径,分别为浴池用水过程、余热发电过程、采暖用水过程。主要就对这三种高炉冲渣水余热回收的利用技术的工艺可行性以及工艺流程进行简单介绍和分析。