高铁型铝土矿和高铁赤泥的综合利用

高铁型铝土矿和高铁赤泥资源丰富,储量巨大,仅我国就有约15亿t的高铁型铝土矿资源,而全球的高铁赤泥库存量达27亿t以上,并以1.2亿t/a的速度增长。高铁铝土矿和高铁赤泥中的Al2O3和Fe2O3的含量在50%左右,而且还含有丰富有价金属资源,采用传统的处理方式不仅造成了严重的环境污染,而且还造成了大量的资源浪费。采用直接还原熔分制备粒铁和C12A7渣系,并对C12A7渣系进行氧化铝浸出的方法是可行的。只有当混合物处在C2S到C12A7的渣线附近时(即C/S=2.0,C/A=1.7),冷却析晶的平衡相中才会出现C2S和C12A7。实验结果表明,当渣系碱度为3.85时,渣铁的分离效果良好,粒铁收得率在90%以上,还原熔分后熔分渣系的组成主要为C2S和C12A7,二者含量在85%左右,C3AS3(石榴石)和C2AS(钙铝黄长石)的含量很少,在10%左右,实验结果和理论分析基本一致。

广西贵港高铁型铝土矿的矿物学特征研究

针对贵港高铁型铝土矿的矿层地质特征、矿石成分、矿物组成以及矿物嵌布关系做了详细的研究,结果表明,贵港高铁型铝土矿矿层结构简单,容易开采;矿石中的Al2O3和Fe2O3总和为65%左右,TiO2含量为1.48%,Ga含量为0.005%~0.027%,A/S在1.2~2.5之间,属于高铁、低铝硅比难选红土型铝土矿。XRD和SEM-EDS分析表明,矿物组成主要为三水铝石、一水硬铝石、赤铁矿、针铁矿、霞石以及少量的锐钛矿和游离石英等,铁矿物、铝矿物、硅矿物三者相互胶结,颗粒微细,同时夹杂有少量的锐钛矿和霞石。

利用赤泥制备硫铝酸盐快硬水泥的研究

用赤泥为原料试验烧制梅塔型水泥和高铁型硫铝酸盐水泥 ,结果表明 ,可烧出标号为 42 5号的高铁型硫铝酸盐水泥。

Leaching behavior of metals from limonitic laterite ore by high pressure acid leaching

The leaching behavior of metals from a nickeliferous limonitic laterite ore was investigated by high pressure acid leaching process for the extraction of nickel and cobalt.The effects of sulfuric acid added,leaching temperature,leaching time and liquid/solid（L/S） ratio on metals extraction were examined.More than 97% Ni,96% Co,93% Mn,95% Mg and less than 1% Fe are extracted under optimum conditions.Analysis of the high pressure acid leaching residue by chemical and XRD analysis indicates that the residual iron and sulfur are mainly present in phases of hematite and alunite,respectively.The high pressure leaching process provides a simple and efficient way for the high recovery of nickel and cobalt from laterite ore,leaving residue as a suitable iron resource.

Behaviors of vanadium and chromium in coal-based direct reduction of high-chromium vanadium-bearing titanomagnetite concentrates followed by magnetic separation

The reduction behaviors of FeO·V2O3 and FeO·Cr2O3 during coal-based direct reduction have a decisive impact on the efficient utilization of high-chromium vanadium-bearing titanomagnetite concentrates. The effects of molar ratio of C to Fe n(C)/n(Fe) and temperature on the behaviors of vanadium and chromium during direct reduction and magnetic separation were investigated. The reduced samples were characterized by X-ray diffraction(XRD), scanning election microscopy(SEM) and energy dispersive spectrometry(EDS) techniques. Experimental results indicate that the recoveries of vanadium and chromium rapidly increase from 10.0% and 9.6% to 45.3% and 74.3%, respectively, as the n(C)/n(Fe) increases from 0.8 to 1.4. At n(C)/n(Fe) of 0.8, the recoveries of vanadium and chromium are always lower than 10.0% in the whole temperature range of 1100-1250 °C. However, at n(C)/n(Fe) of 1.2, the recoveries of vanadium and chromium considerably increase from 17.8% and 33.8% to 42.4% and 76.0%, respectively, as the temperature increases from 1100 °C to 1250 °C. At n(C)/n(Fe) lower than 0.8, most of the FeO·V2O3 and FeO·Cr2O3 are not reduced to carbides because of the lack of carbonaceous reductants, and the temperature has little effect on the reduction behaviors of FeO·V2O3 and FeO·Cr2O3, resulting in very low recoveries of vanadium and chromium during magnetic separation. However, at higher n(C)/n(Fe), the reduction rates of FeO·V2O3 and FeO·Cr2O3 increase significatly because of the excess amount of carbonaceous reductants. Moreover, higher temperatures largely induce the reduction of FeO·V2O3 and FeO·Cr2O3 to carbides. The newly formed carbides are then dissolved in the γ(FCC) phase, and recovered accompanied with the metallic iron during magnetic separation.

后江桥铁锰铅锌矿综合利用途径的探讨

一、后江桥矿资源特点后江桥矿自1958年以来先后有几个地质队进行了勘探工作。省地质局四○九队于1980年底正式提交了《湖南省道县后江桥铁锰铅锌矿初步勘探报告》,矿床规模、矿体形态、产状及其变化规律已经查明,全区共获C1+C2级铁锰矿储量约3000万吨,其中富矿占82％,铅金属量17万吨,锌金属量50万吨,尚伴生一定量的镉和银。是一重要的矿产基地。该矿主要工业矿体有五个,其中Ⅱ号矿体最大,占全区铁锰矿储量的85％。矿体厚1.46—74.4米,平均21.65米。矿石平均成分见表1。

原子吸收分光光度法测定锰矿中微量钴镍

本文介绍了以金的空心阴极灯来扣除背景吸收值的分析方法。经多年生产实践证明:用该法来测定铁锰矿中微量钴镍时,提高了测定的准确性。

玛瑙山锰矿资源的综合利用及提高经济效益的途径

一、资源特点玛瑙山锰矿是一个中型锰矿企业,拥有玛瑙山、玉皇庙、枫树下等六个以铁、锰为主,并伴生铅、银等有用组分的多金属矿床。该矿床为一热液改造型铁锰矿床,赋存于棋梓桥白云质灰岩之中。矿体受层间构造的控制,埋藏较浅,大部分裸露地表,适宜露天开采。主要矿石类型分氧化铁锰矿和原生铁锰矿两类。前者主要有用矿物有硬锰矿、磁铁矿、褐铁矿、软锰矿等,脉石矿物主要为粘土类矿物;后者主要有用矿物有硫锰矿。

江西众埠街项目发现厚大铁锰矿层

江西有色矿勘院承担的众埠街项目ZK302孔发现一厚大铁锰矿层。江西有色矿勘院众埠街项目是2015年新立、2016年续作的江西省地勘基金项目,至今已累计施工钻孔7500m,目前正在施工的钻孔ZK302为2016年度的最后一个钻孔。施工结果显示,该孔在孔深300.

Effect of Calcium Oxide Additive on the Performance of Iron Oxide Sorbent for High-Temperature Coal Gas Desulfurization

The effect of calcium oxide additive in iron oxide sorbent for hot gas desulfurization was investigated by XRD and TPR techniques.XRD characterization showed that CaO was highly dispersed after the calcination of sorbents.Calcium sulfate formed in the desulfurization was decomposed and regenerated to CaO by reacting with CO before the next sulfidation process.Calcium participated in every sulfidation/regeneration cycle and contributed to the enhancement of sulfur capacity.The TPR results showed that the reduction temperature of the sorbent increased with the increase of the content of calcium.Calcium played a role of retarding reduction.Therefore,the addition of calcium oxide additive will benefit the utilization of iron oxide sorbent in strongly reducing atmospheres.

Effects of basicity and temperature on mineralogy and reduction behaviors of high-chromium vanadium-titanium magnetite sinters

The effects of basicity and temperature on the reduction process of Hongge high-chromium vanadium-titanium magnetite(HCVTM)sinter were investigated in this work.The main characterization methods of X-ray fluorescence(XRF),X-ray diffraction(XRD),scanning electron microscope(SEM),and metallographic microscope were employed in this study.In this work,the reduction of HCVTM sinter with different temperature and basicity were experimented.The Fe,FeO,and TiO in reductive samples increase with increasing basicity and temperatures.The increase of basicity and temperature is favorable to the reduction of HCVTM sinter.The Fe phase has out-migration tendency to the surface of sinter while the perovskite and silicate phases have in-migration tendency to the inside of sinter.The reduction degradation index(RDI)decreases while the reduction index(RI)increases with increasing basicity.The RI increases from 67.14%to 82.09%with increasing temperature from 1073 K to 1373 K.

Efficient separation of alumina and silica in reduction-roasted kaolin by alkali leaching

Alkali leaching was employed to investigate the separation of alumina and silica in roasted kaolin obtained by roasting kaolin alone in air at 1273 K for 60 min and in clinker prepared by roasting the mixed raw meal of kaolin,ferric oxide and coal powder with Fe2O3/Al2O3/C molar ratio of 1.2:2.0:1.2 in reducing atmosphere at 1373 K for 60 min.The thermodynamic analyses and alkali leaching results show that the composition of the Al-Si spinel in roasted kaolin is close to that of 3Al2O3·2SiO2 and the spinel is dissolved with increasing leaching time,resulting in difficulty in deeply separating alumina and silica in kaolin by the traditional roasting-leaching process.On the contrary,the efficient separation of alumina and silica in kaolin can be reached by fully converting kaolinite into insoluble hercynite and soluble free silica,namely quartz solid solution and cristobalite solid solution,during reduction roasting,followed by alkali leaching of the obtained clinker.Furthermore,experimental results from treating high-silica diasporic bauxite indicate that the reduction roasting-alkali leaching process is potential to separate silica and alumina in aluminosilicates.

Regression model for daily passenger volume of high-speed railway line under capacity constraint

A non-linear regression model is proposed to forecast the aggregated passenger volume of Beijing-Shanghai high-speed railway(HSR) line in China. Train services and temporal features of passenger volume are studied to have a prior knowledge about this high-speed railway line. Then, based on a theoretical curve that depicts the relationship among passenger demand, transportation capacity and passenger volume, a non-linear regression model is established with consideration of the effect of capacity constraint. Through experiments, it is found that the proposed model can perform better in both forecasting accuracy and stability compared with linear regression models and back-propagation neural networks. In addition to the forecasting ability, with a definite formation, the proposed model can be further used to forecast the effects of train planning policies.

Oxidative Desulfurization of Model Sulfur Compound by Potassium Ferrate in the Presence of Phosphomolybdic Acid Catalyst

In this work, the removal of thiophene from simulated oil has been studied by using the adsorption, extraction and oxidation/adsorption methods, respectively. In the adsorptive desulfurization process, different commercial adsorbents were used to eliminate thiophene at ambient pressure and mild temperature, and the results showed that carbon powder had the best adsorption ability. In the extractive desulfurization process, the best desulfurization result was obtained when DMF is used. In the oxidative/adsorptive desulfurization procedure using synthesized potassium ferrate as the oxidant and phosphomolybdic acid solution as the catalyst, thiophene was oxidized and removed from hydrocarbons in combination with active carbon adsorption, and the residual sulfur content of simulated oil could be reduced to 15.3mg/L from the original level of 200mg/L, with the desulfurization rate reaching 92.3%.

An evaluation of the economic,social,and ecological risks of China-Mongolia-Russia high-speed railway construction and policy suggestions

The construction of China-Mongolia-Russia high-speed railways is a strategic move to promote transportation infrastructure inter-connectivity between these countries, which will accelerate the implementation of the China-Mongolia-Russia Economic Corridor. However, well-planned China-Mongolia-Russia high-speed railways demand accurately identifying construction risks, scientifically evaluating risk levels, and mapping the spatial distribution of these risks. Therefore, this study established the integrated risk evaluation model(IREM) to scientifically evaluate the economic, social, and ecological risks of China-Mongolia-Russia high-speed railway construction and determine their magnitude and spatial distribution pattern. Based on this analysis, we propose designs for the east and west China-Mongolia-Russia high-speed railways and policy suggestions to mitigate construction risks. Suggestions include developing innovative cooperation of the "high-speed railway for resources and market", strengthening communication and technology dissemination, and applying innovative engineering techniques and setting buffers; establishing collaborative prevention and control systems to mitigate the three major ecological risks in the China, Mongolia, and Russia trans-border areas; and promoting economic integration by improving strategic coordination. In summary, this study provides scientific support for designing the China-Mongolia-Russia high-speed railways minimizing construction risks.

High-pressure experimental verification of rutile-ilmenite oxybarometer: Implications for the redox state of the subduction zone

The more oxidized mantle peridotites above subducting slabs than stable continental areas have been attributed to the infiltration of some oxidizing fluids released from the subducting slabs. However, knowledge for the redox states of the slabs itself is very limited. Until now, few oxybarometers can be directly used to constrain the redox states of the subducting slabs.The rutile-ilmenite oxybarometer was proposed and successfully applied to constrain the oxygen fugacity of mantle assemblages.However, its application to rocks equilibrated at crustal P-T conditions has been hampered by some uncertainties in an early solid solution model of ilmenite. With a newly-released solid solution model for the ilmenite, we have conducted high-P experiments(at 3 and 5 GPa, and 900–1300°C) to test the accuracy of this oxybarometer. The experiments were performed with their oxygen fugacities controlled by the CCO buffer(i.e., C+O_2=CO_2). We demonstrated that the oxygen fugacities calculated for our high-P experimental products by using the rutile-ilmenite oxybarometer were in excellent agreement with the fO_2 dictated by the CCO buffer, suggesting a wide applicability of this oxybarometer to crust rocks. As examples, the rutile-ilmenite oxybarometer has been used to constrain the oxygen fugacities of some metamorphic rocks such as eclogite, granulite and amphibolite usually observed from the subduction zones.

Formation and strain distribution of Ni/NiO core/shell magnetic nanoparticles fabricated by pulsed laser deposition

Nucleation and growth lead to substantial strain in nanoparticles embedded in a host matrix. The distribution of strain field plays an important role in the physical properties of nanoparticles. Magnetic Ni/NiO core/shell nanoparticles embedded in the amorphous Al2O3 matrix were fabricated by pulsed laser deposition. The results from a high-resolution transmission electron microscope also revealed that the core/shell nanoparticles consist of a single crystal Ni core with a faced-centered cubic struc- ture （Space Group FM-3M） and polycrystalline Nit shell with a trigonal/rhombohedral structure （Space Group R-3mH）. The growth strain of Ni/NiO core/shell nanoparticles embedded in the Al2O3 matrix was investigated. Finite element calculations clearly indicate that the Nit shell incurs large compressive strain. The compressive strain existing at the Nit shell area ena- bles the shell material at the interface to adapt to the lattice parameters of Ni core. This process results in a relatively good crystallinity near the interface, which may be associated with the higher exchange coupling between the ferromagnetic Ni core and antiferromagnetic Nit shell.