Effect of oxidization on enrichment behavior of TiO_2 in titanium-bearing slag

Due to the dispersed distribution of the titanium component in various mineral phases and very fine grain size, it is difficult to recover the titanium component from the slag. In order to utilize titanium resources, selective enriching and selective growing of the titanium component from the molten slag is expected. In this paper, the selection of the best titanium enrichment phase and the effect of oxidization on the enrichment of titanium by blowing air into the molten slag were studied. The results showed that through oxidizing the slag, the content of the perovskite phase increases while that of the other titanium-bearing mineral phases decreases until they disappear. Most titania resources were enriched into the perovskite phase and increase in size. The process of enrichment and growth is easily carried out.

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.

BFS固井液在吉林油田油层套管固井中的应用

水淬高炉矿渣(BFS)是炼铁厂的副产品,具有水硬性质,目前已广泛用于建筑水泥———矿渣水泥的生产。在我国,BFS大量应用于石油固井业始于20世纪90年代中期。由于用BFS配制的固井液具有密度低、密度范围可调、强度高、滤失量小、无游离水、触变性好、稠化时间可调、无体积收缩等特点,可广泛用于常规和复杂油气井固井。文章概述了BFS固井液及其性质、BFS的筛选、BFS固井液的性能、BFS固井液的配制及现场施工方法,并以吉林油田油层套管BFS固井为例,对BFS固井液的固井质量进行了阐述。实践表明,吉林油田油层套管采用BFS固井,CBL测井表明固井质量优质。

掺加BFS的乳化沥青冷再生混合料路用性能研究

为验证在乳化沥青冷再生混合料中掺加高炉矿渣(blast furnace slag, BFS)的可行性并分析掺加BFS的乳化沥青冷再生混合料的路用性能,采用直接掺加BFS和以消石灰做激发剂掺加BFS两种方案,与掺加1.5%水泥的冷再生技术方案进行对比试验。通过测试干湿劈裂强度、冻融劈裂强度、60℃动稳定度和60℃抗剪强度、单轴压缩等性能指标,最终确定了v用于乳化沥青冷再生混合料的合理利用方式。研究结果表明:干湿劈裂强度试验无法有效地反映乳化沥青冷再生混合料水稳定性差异;冻融劈裂强度试验能有效地评价其水稳定性。在乳化沥青冷再生混合料中用BFS直接替代水泥会降低混合料的水稳定性;采用1.5%BFS+0.3%消石灰激发剂后,可使混合料具备与掺加1.5%水泥基本相当的路用性能。

Status and development of mineral wool made from molten blast furnace slag

This study describes the characteristics of mineral wool and its applications,and also introduces the traditional process of mineral wool made from molten blast furnace （BF） slag. Compared with high energy consumption of the traditional process,the production of mineral wool by using molten BF slag will be able to take full advantage of the sensible heat of molten slag, and also reduce production costs. However, there are also further issues to resolve such as how to obtain the required amount of molten BF slag and how to make it homogeneous. Based on the physical and chemical properties of the molten BF slag,the investigation into the relationship between temperature and viscosity under different acidity coefficients of the slag and silicon mixture was conducted. Combined with the crystallization and phase diagram of slag wool, its heat resistance, water resistance, durability and corrosion resistance were analyzed. Finally, trends of the technology development are proposed.

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.

Effects of the continuous cooling process conditions on the crystallization and liberation characteristics of anosovite in Ti-bearing titanomagnetite smelting slag

This study involved the investigation of the effects of the continuous cooling process conditions on the crystallization and liberation characteristics of anosovite in Ti-bearing titanomagnetite smelting slag. The samples were heated until melting and then the temperature was held at 1650℃ for nearly 0.5 h;subsequently, the samples were cooled at different cooling rates to different temperatures and water-quenched after being held for different times at these temperatures. Last, the obtained crystallized samples were used to analyze the crystallization and liberation characteristics. It was found that, during the continuous cooling process, anosovite particles were found to initially precipitate in the slag at a relatively high crystallization temperature, showing the characteristics of euhedral crystal. The precipitation and growth of anosovite grain is strong and the morphology of anosovite was basically not affected by the continuous cooling conditions. From the morphology perspective, the formed anosovite is an excellent Ti-rich phase to be selective separated. The formation of spinel and diopside is negative for the liberation and selective separation of the anosovite phase. The crystallization diagrams of TiO2-MgO-CaO-SiO2-Al2O3-FeO slag undergoing different continuous cooling processes were constructed to help to determine the optimal continuous cooling–quenching condition for selective separation of anosovite. Moreover, the addition of B2O3 can enlarge the range of the optimal continuous cooling–quenching conditions for selective separation of anosovite.

Mechanisms of phosphate removal from aqueous solution by blast furnace slag and steel furnace slag

We report the adsorption of phosphate and discuss the mechanisms of phosphate removal from aqueous solution by burst furnace slag (BFS) and steel furnace slag (SFS). The results show that the adsorption of phosphate on the slag was rapid and the majority of adsorption was completed in 5~10 min. The adsorption capacity of phosphate by the slag was reduced dramatically by acid treatment. The relative contribution of adsorption to the total removal of phosphate was 26%~28%. Phosphate adsorption on BFS and SFS follows the Freundlich isotherm, with the related constants of k 6.372 and 1/n 1.739 for BFS, and of k 1.705 and 1/n 1.718 for SFS. The pH and Ca2+ concentration were decreased with the addition of phosphate, suggesting the formation of calcium phosphate precipitation. At pH 2.93 and 6.93, phosphate was desorbed by about 36%~43% and 9%~11%, respectively. These results indicate that the P adsorption on the slag is not completely reversible and that the bond between the slag particles and adsorbed phosphate is strong. The X-ray diffraction (XRD) patterns of BFS and SFS before and after phosphate adsorption verify the formation of phosphate salts (CaHPO4·2H2O) after adsorption process. We conclude that the removal of phosphate by BFS and SFS is related to the formation of phosphate calcium precipitation and the adsorption on hydroxylated oxides. The results show that BFS and SFS removed phosphate nearly 100%, indicating they are promising adsorbents for the phosphate removal in wastewater treatment and pollution control.

Research on the performance of steel slag and blast furnace slag composite admixture

This study investigates the properties of Baosteel steel slag and blast furnace （BF） slag in order to develop high-performance steel slag and BF slag composite admixture by optimizing the composite mixing technique. Based on the investigation of the stability of steel slag powder and the performance of cement mortar in different mixing ratios and different adding amounts of steel slag and BF slag composite admixture, rational mixing ratios and the adding amount range of steel slag and BF slag composite admixture were determined.

高炉炉渣处理技术及发展趋势

介绍了国内高炉炉渣处理技术现状,主要包括水渣处理中的底滤法、INBA法的现状与发展。现有高炉炉渣处理技术存在着水渣处理耗水量大、污染环境、高炉炉渣余热回收率低和需要额外能源消耗等问题。离心粒化法节约水资源、无污染物排放且能有效回收炉渣余热,是高炉炉渣处理未来的发展趋势。

高炉渣均质化行为及其粒化效果研究

利用动态黏度实验法研究了高炉渣的均质化行为,构建熔渣调质过程动力学模型,同时对高炉渣均质化状态进行验证,并对最终粒化效果进行了分析。结果表明,均质化时间随调质剂添加量增加先减少后增加,添加量为15.43%时均质化时间最短;高炉渣粒度大于1.75 mm时,均质化时间明显增加;随炉渣温度升高,均质化时间逐渐缩短,通过与充分均质化高炉渣的成分及矿相进行对比,验证了高炉渣在黏度值达到稳定时已完成了均质化。粒化渣珠粒径主要位于1~2.5 mm,基本呈正态分布;高炉渣均质化处理后非晶相含量均高于85%,满足国家标准要求。

广西翅冀钢铁矿渣微粉系统及大型立磨技术的应用和分析

在刚投产的项目中,MTP270型矿渣立磨的单机年干粉产量已经达到220万吨以上。广西翅冀钢铁有限公司的矿渣微粉系统配置了MTP270型超大型矿渣立磨,该系统在减少项目占地、降低项目投资、降低综合能耗、降低生产运行成本等方面表现突出,提高了产品的市场竞争力。本文对MTP270超大型矿渣立磨在广西翅冀钢铁钢铁有限公司矿渣微粉生产线中的应用进行了分析。

武钢铜冷却壁高炉炉墙结厚原因分析

对铜冷却壁在武钢大型高炉的应用情况进行了阐述。选取8号高炉为代表,对武钢铜冷却壁高炉炉墙结厚的过程进行跟踪分析,找出炉墙结厚的原因,并提出防止炉墙结厚、维护铜冷却壁高炉操作炉型的对策措施。边缘气流长期不足、操作制度未能适应入炉料结构变化、渣皮脱落后操作不合理是武钢铜冷却壁高炉炉墙结厚的主要原因。须通过十字测温和炉身热负荷管理办法,控制适宜的边缘气流,入炉料结构发生变化后要进行针对性调整,渣皮脱落后的煤气流控制要遵循疏通中心引导边缘的原则,才能从根源上消除铜冷却壁炉墙结厚现象,保持铜冷却壁高炉良好的操作炉型。

高炉渣急冷干式粒化处理工艺分析

介绍了3类已经进行过工业试验的急冷干式粒化方法——滚筒法、风淬法和离心粒化(转杯)法,分析了它们的优缺点。对高炉渣急冷干式粒化的节水、节能和环保效益进行了估算,同时指出了急冷干式粒化技术的难点。

含碱高炉渣排碱、脱硫能力的实验研究

为探讨高炉渣排碱、脱硫能力间的关系,根据广钢实际高炉渣成分,通过实验研究了w(CaO)/w(SiO2),w(MgO),w(Al2O3)对炉渣排碱、脱硫的影响.结果表明:w(CaO)/w(SiO2)对炉渣的排碱、脱硫能力影响较大,二者相互矛盾;w(MgO)升高,炉渣排碱能力降低,含碱炉渣最佳脱硫对应的w(MgO)比普通炉渣低3%.w(Al2O3)升高,炉渣的排碱能力变化不大,而脱硫能力迅速降低.广钢高炉适宜的炉渣成分为:w(CaO)/w(SiO2)保持在1.0,w(MgO)保持在12%,w(Al2O3)保持在15%.

高炉渣钾容量的试验研究

为降低碱金属对高炉的危害，提高炉渣的排碱能力，采用气-渣平衡法测定了1723K时高炉渣的钾容量。依据广钢实际高炉渣成分，用纯化学试剂配制炉渣，用一定组成K（g）-CO-CO2-Ar混合气体提供一定的氧分压和钾分压。研究表明：试验条件下，w（MgO）和w（Al2O3）一定时，钾容量随w（CaO）／w（SiO2）的增大而减小；在w（CaO）／w（SiO2）和w（Al2O3）一定时，钾容量随w（MgO）的增大而增大；在w（CaO）／w（SiO2）和w（MgO）一定时，钾容量随w（Al2O3）的增大而增大；当[w（CaO）Ww（MgO）]／w（SiO2）和w（Al2O3）固定不变时，增加w（MgO），降低w（CaO），钾容量明显增大。广钢炉渣的合理成分为：w（CaO）／w（SiO2）保持在1．0，w（MgO）保持在12％～15％，w（Al2O3）不超过15％。