Chemical benefication of Rosetta ilmenite by direct reduction leaching

Rosetta ilmenite assaying 40–47% TiO₂ is not suitable for processing to titanium metal or TiO₂ pigment due to its high iron content. The present paper is concerned with studying a rapid and economic process to upgrade Rosetta ilmenite concentrate into synthetic rutile through simultaneous iron removal and titanium insolubilization. This has been possible by using HCl in a low acid/ilmenite mole ratio under reducing conditions created by the addition of metallic iron. A synthetic rutile assaying 89% TiO₂ was prepared from an ilmenite concentrate of about 47% TiO₂. A remaining total iron content of less than 7% Fe₂O₃ is most probably due to complex mineralogical composition resulting from the existence of the three fundamental solid solution series in the FeO–Fe₂O₃–TiO₂ ternary system.     

Preparation of High-Grade Titania Slag from Ilmenite-Bearing High Ca and Mg by Vacuum Smelting Method

Ilmenite produced from the Panxi area in China has high impurities such as Ca and Mg. High-grade titanium (Ti) slag can be obtained by the electric arc furnace process, a traditional method of treating ilmenite. Thus, Ti slag prepared from the Panxi ilmenite contains high CaO and MgO, exceeding 5 pct of the slag content. This high CaO and MgO content confers considerable difficulty in producing titania (TiO₂) white using fluidizing chlorination. In this study, a new process named vacuum separation was found to produce high-grade TiO₂ materials. The effects of separation temperature and time on the TiO₂ grade were studied. The high-grade TiO₂ slag, which has 93 pct TiO₂, <0.1 pct MgO, <1.2 pct SiO₂, and <0.5 pct CaO, can be produced at 1823 K (1550 °C) in 45 minutes through the proposed method.     

Vacuum Carbothermic Reduction of Panzhihua Ilmenite Concentrate: A Thermodynamic Study

Electric arc furnace is mainly used in the production of high titania slag; however, since impurities cannot be eliminated, this causes difficulty in the production of titania pigment with chlorination process. Consequently, removing impurities is the crucial way to deal with low-grade ilmenite, especially for the Panzhihua ilmenite concentrate in China. This article studied the theoretical calculation of vacuum carbothermic reduction of Panzhihua ilmenite concentrate. Thus, when the temperature was higher than 1600°C and the carbon amount was greater than 12%, all of the Fe almost entered into the gas phase. When the temperature was higher than 1300°C and the carbon amount was greater than 14%, magnesium also entered the gas phase. When the temperature was higher than 1100°C, most of the element manganese was volatilized in the gas phase. The TiO₂ grade increased with the increase in carbon amount (14%). When the temperature was higher than 1600°C and the carbon amount was less than 14%, the TiO₂ grade in the slag phase could reach the maximum value, which can be used for the chlorination process to prepare titanium dioxide.     

攀西地区白马钒钛磁铁矿工艺矿物学探讨

为了查明攀西地区白马钒钛磁铁矿工艺矿物学特征,利用化学分析、光学显微镜、扫描电子显微镜、矿物自动分析仪(AMICS)等先进的分析手段,对白马钒钛磁铁矿矿石展开了深入研究。结果表明,矿石的主要矿物为钛磁铁矿、钛铁矿、钙长石、透辉石和蛇纹石等。矿石中Fe、Ti、V的质量分数分别为25.05%、3.46%和0.13%,可以综合回收利用;其中有74.13%的铁以钛磁铁矿的形式存在,13.16%的铁以含铁硅酸盐的形式存在,有63.72%的钛以独立矿物钛铁矿及钛铁矿(客晶)的形式存在,33.67%的钛以类质同象形式存在于钛磁铁矿中。矿石中钛磁铁矿、钛铁矿和硫矿物均以中粒为主,钛铁矿(客晶)和镁铝尖晶石(客晶)的嵌布粒度绝大部分为微粒,小于0.010 mm。矿石中13.16%的铁赋存于硅酸盐中以及大部分钛磁铁矿中含钛铁矿(客晶)和镁铝尖晶石(客晶),是影响铁精矿品位的主要因素。     

菲律宾某含磁铁矿海砂磁选试验研究

菲律宾某海砂以钛磁铁矿为主,且粒度分布较粗,针对该特点,采用预先筛分-磁选-磨矿分级-磁选的工艺,从含铁7.18%的原矿中获得了含铁59.03%、回收率为32.31%的铁精矿,使该海砂得到充分利用。     

Beneficiation Studies on Recovery of Secondary Sources of Iron from Ferrigenous Alluvial Sands

Beneficiation studies were carried out on iron bearing alluvial sand to recover iron values for pelletisation. The studies include detailed mineralogical characterization, physical and chemical characteristics, beneficiation studies including grinding, magnetic and high tension separation. The results of these investigations indicate that the samples contain 50.2% Fe and 8.2% SiO₂ on average. The mineralogical studies reveal that the sand contains dominantly heavy minerals with small amount of quartz. The heavy minerals are magnetite and ilmenite with small quantities of amphibole and pyroxene group minerals. Detailed beneficiation studies carried out by various techniques indicated that the iron content can be upgraded by simple low intensity wet magnetic separation after grinding the sample to below 210 microns. A product with 62.7% Fe can be obtained at 65.5% yield. The product obtained can be used for pelletisation by blending with suitable high grade iron concentrate.     

陕西某低品位钒钛磁铁矿资源综合利用新工艺研究

陕西某钒钛磁铁矿资源,TFe品位为15．85％,TiO2品位2．94％、V2O5品位0．14％,属尚难利用低品位钒钛资源。通过采用新型ZCLA选矿机进行粗粒湿式抛尾,再采用弱磁选回收钒钛磁铁矿,强磁选一重选工艺回收钛铁矿,最终实现该矿铁、钛、钒资源的综合利用,钒钛磁铁矿产率13．37％,品位可达到60．18％～65．27％,磁性铁回收率达到98％以上,钛铁矿产率1．94％,钛铁矿回收率84．09％以上,铁精矿含V2O5富集到0．89％～0．93％,改变了矿山只能回收铁资源的现状,开创了钒钛铁资源综合回收的新工艺。     

云南某低品位钛铁矿选矿工艺试验研究

通过对TiO2品位小于6％的钛铁矿进行磁选试验、螺旋溜槽试验、摇床试验等流程试验研究,最终采用原矿脱泥-弱磁除铁—强磁抛尾-摇床精选的联合工艺流程,可得到TiO2品位为46.18％,回收率为53.21％的钛精矿.     

Effects of embedding direct reduction followed by magnetic separation on recovering titanium and iron of beach titanomagnetite concentrate

Embedding direct reduction followed by magnetic separation was conducted to fully recover iron and titanium separately from beach titanomagnetite(TTM).The influences of reduction conditions,such as molar ratio of C to Fe,reduction time,and reduction temperature,were studied.The results showed that the TTM concentrate was reduced to iron and iron-titanium oxides,depending on the reduction time,and the reduction sequence at 1 200°C was suggested as follows:Fe_(2.75)Ti_(0.25)O_4→Fe_2TiO_4→FeTiO_3→FeTi_2O_5.The reduction temperature played a considerable role in the reduction of TTM concentrates.Increasing temperature from 1 100 to 1 200°C was beneficial to recovering titanium and iron,whereas the results deteriorated as temperature increased further.The results of X-ray diffraction and scanning electron microscopy analyses showed that low temperature(≤1 100°C)was unfavorable for the gasification of reductant,resulting in insufficient reducing atmosphere in the reduction process.The molten phase was formed at high temperatures of 1 250-1 300°C,which accelerated the migration rate of metallic particles and suppressed the diffusion of reduction gas,resulting in poor reduction.The optimum conditions for reducing TTM concentrate are as follows:molar ratio of C to Fe of 1.68,reduction time of 150 min,and reduction temperature of 1 200°C.Under these conditions,direct reduction iron powder,assaying 90.28 mass%TFe and 1.73 mass% TiO_2 with iron recovery of 90.85%,and titanium concentrate,assaying 46.24mass% TiO_2 with TiO_2 recovery of 91.15%,were obtained.     

选铁尾矿回收钛铁矿及硫化矿的工艺研究

研究了攀枝花钒钛磁铁矿选铁尾矿的物质特性，进行选铁尾矿回收钛铁矿及硫化矿的工艺研究，提出了几种流程：当品种为钛白粉钛精矿，扩大连选流程是强磁-浮选，强磁-强磁-浮选，实验室流程是重选-浮选，分级强磁-电选，重选-强磁-浮选；当品种为造块用钛精矿，扩大连选流程是强磁-强磁-浮选，实验室流程是强磁-浮选，强磁-重选-浮选。在小型试验中分级强磁-电选工艺得到钛精矿产率为13．93％，品位为49．2l％，回收率60．63％较好指标。     

CaO对海滨钛磁铁矿精矿直接还原?磁选工艺中还原气氛的影响

以铁品位为58.58%、TiO₂品位为12.04%的海滨钛磁铁矿精矿为试样,进行煤基直接还原–磁选试验。从反应产生的CO和CO₂气体组成、总反应的气化速率、CO分压值、金属化率、矿物组成等角度进行分析,查明了CaO在海滨钛磁铁矿精矿直接还原?磁选工艺中的作用机理。研究结果表明,CaO可以提高还原剂的气化速率,促进钛磁铁矿的还原,增加CO₂气体的产生量,从而降低CO分压值。同时发现CaO可以参与固固反应,降低含钛矿物中的FeO含量,也有利于钛、铁组分的迁移和富集,促进金属铁颗粒的聚集长大。因此,添加CaO有利于通过磨矿?磁选促进钛铁分离与回收。      

攀西钛精矿主要杂质元素赋存状态研究

通过对攀西钒钛磁铁矿矿物结构及攀西钛精矿选钛工艺研究,同时采用XRD、扫描电镜对攀西钛精矿进行深度剖析,得出在攀枝花钛精矿中主要元素分布及杂质元素的赋存状态。攀西钛精矿是以偏钛酸铁(FeO·TiO_2)晶格为基础,含有Mg、Mn等氧化物杂质的固溶体,主要杂质元素Si、Ca、Mg、Al、Fe、Ti等物质以一种或多种氧化物形式固溶于钛铁矿伴生相硅酸盐中。针对不同用途,提出通过深度解粒,调整钛精矿选别工艺参数,可生产出高品质的钛精矿,实现高附加值利用。     

Soda ash roasting of titania slag product from Rosetta ilmenite

A soda ash roasting process for upgrading titania slag product of Rosetta ilmenite to a high grade titanium dioxide (TiO₂) is presented. The roasting process was carried out at moderate to high temperatures to yield a reaction product that would be easily decomposed by subsequent leaching procedures. Factors affecting the roasting process; namely the soda ash ratio to the slag material, the roasting time and temperature were studied. The optimised conditions used a Na₂CO₃ to slag ratio of 0.55:1 at a roasting temperature of 850 °C for 0.5 h duration period. The impurities associated with the roasted slag were subjected to leaching with water and dilute hydrochloric acid solution leaving synthetic rutile (TiO₂) as insoluble residue. To improve the quality of the synthetic rutile, an alkaline leaching step was added to remove the excess silica present in the treated titania slag. This method is capable of producing high purity synthetic rutile assaying about 97% TiO₂.     

Upgrading Titanium Ore Through Selective Chlorination Using Calcium Chloride

To develop a simple and effective process for upgrading low-grade titanium ore (ilmenite, mainly FeTiO₃), a new selective chlorination process based on the use of calcium chloride (CaCl₂) as the chlorine source was investigated in this study. Titanium ore and a titanium ore/CaCl₂ mixture were placed in two separate crucibles inside a gas-tight quartz tube that was then positioned in a horizontal furnace. In the experiments, the titanium ore in the two crucibles reacted with either HCl produced from CaCl₂ or CaCl₂ itself at 1100 K (827 °C), leading to the selective removal of the iron present in the titanium ore as iron chlorides [FeCl _x (l,g) (x = 2, 3)]. Various kinds of titanium ores produced in different countries were used as feedstock, and the influence of the particle size and atmosphere on the selective chlorination was investigated. Under certain conditions, titanium dioxide (TiO₂) with purity of about 97 pct was directly obtained in a single step from titanium ore containing 51 pct TiO₂. Thus, selective chlorination is a feasible method for producing high purity titanium dioxide from low-grade titanium ore.     

Solid-phase prereduction of iron-vanadium concentrates and liquid-phase separation of the products of their reduction

The transformations that occur in ore grains during solid-phase carbon reduction of the metals from the iron-vanadium concentrates formed upon the beneficiation of the titanomagnetite ores from Southern Ural deposits are studied. Upon heating to 1000°C, the solid solution in titanomagnetite grains decomposes with the formation of magnetite and ilmenite; the reduction of iron begins in the temperature range 1080–1110°C, and the reduction of titanium begins at above 1215°C. The reaction mixture should be held at 1250°C for 45 min to ensure almost complete iron reduction and the minimum degree of titanium reduction. For rapid separation melting, this procedure results in vanadium-containing cast iron (0.43–0.5% V) with <0.15% Ti and a slag with 42–43% titanium oxides.     

新药剂在毕机沟钛铁矿浮选试验中的应用

通过对强磁选粗钛精矿浮选钛铁矿的试验研究,寻找出了当进入浮选作业的钛铁矿品位为15.30%时,合适的选矿流程结构和药剂制度。试验结果表明:采用预先脱硫一粗三精一扫的闭路流程,硫酸作p H调整剂和抑制剂,JS-3作选钛捕收剂,柴油辅助捕收的流程结构和药剂制度,能获得含Ti O2为46.63%、回收率为76.12%的钛精矿。     

风化型钛铁矿矿物学与选矿工艺的研究

试验以云南某地的风化型钛铁矿为研究对象,原矿含TiO2品位为5．68％,TFe品位14．00％,该试验主要进行了风化型钛铁矿的工艺矿物学研究与钛矿物选别工艺的研究,通过最佳的选矿工艺,从而得到含TiO2品位为46．50％,回收率达到49．77％的钛精矿,对于原矿可回收钛的回收率为74．73％;Fe34．44％。可以相信,该钛铁矿的工艺矿物学与选矿工艺的研究对于选别风化型钛铁矿领域具有一定的指导意义。     

攀西细粒级钛铁矿高效回收工艺研究

针对攀西地区追求钒钛铁精矿品质造成选铁尾矿变细,高梯度强磁机难以同时兼顾细粒级钛铁矿品位和回收率的问题,采用高梯度强磁机与悬振锥面选矿机作为浮选原料富集设备,并与浮选组成联合选别工艺进行实验室对比研究。试验表明:设置有悬振作业的浮选原料中干扰浮选的-19μm矿泥含量低于单一强磁作业,且"悬振+浮选"联合流程对TiO_2品位10.57%的细粒级钛铁矿回收效果最优,能获得产率13.29%、TiO_2品位47.20%、TiO_2回收率60.00%的合格钛精矿。     

以转底炉技术利用钛资源的基础研究

提出了一种以转底炉煤基直接还原技术利用钛资源的新工艺及两个不同的方案。该工艺以攀枝花钒钛磁铁精矿或钛精矿粉、煤粉和少量添加剂组成的复合球团为原料,在高温加热条件下将含钛矿中的氧化铁还原为铁,经渣铁分离后获得生铁和富集了的钛渣。第一方案以钒钛磁铁精矿配20%钛精矿为原料,还原后渣铁自然分离,得到块铁和品位为50%左右的钛渣;第二方案以钛精矿为原料,还原后经破碎磁选分离得到粒铁和TiO2富集率为～75%的钛渣。对这两种方案均进行了初步试验,确定了合理的工艺条件。     

河南某难选低品位微细粒金红石选矿试验研究

对河南省某低品位难选细粒金红石与钛铁矿进行了矿物学及分选试验研究。矿石中金红石与钛铁矿均有回收利用价值,金红石矿物呈他形、半自形柱状,多以集合体形式沿脉石矿物的片理方向排列分布,钛铁矿连生体呈细小的粒状被角闪石、黑云母和石英包裹。目的矿物金红石嵌布粒度较细,属细粒、微细粒不均匀嵌布,粒度区间跨度较大,一般为0.037~0.074 mm。在原矿TiO2含量为2.10%,Fe2O3含量为9.69%的情况下,经重选—磁选—酸洗—浮选的原则流程可得到金红石精矿品位为88.25%、回收率为97.80%,钛铁矿精矿品位为11.76%、回收率为89.57%的较好指标。其中重选为一粗一精,强磁选扫二、扫三中矿合并再重选的流程;磁选为一粗四扫,扫一、扫四中矿与粗选精矿合并成磁选精矿进行酸洗;浮选为一粗两精两扫流程。研究结果对难选低品位微细粒金红石矿的综合利用具有一定的指导意义。