Genesis of Langrial Iron Ore of Hazara area, Khyber Pakhtunkhwa, Pakistan

In this paper, a detailed mineralogical and genesis investigation have been carried out in the seven locations of the Iron Ore in Hazara area. Thick bedded iron ore have been observed between Kawagarh Formation and Hangu Formation i.e, Cretaceous-Paleocene boundary. At the base of Hangu Formation, variable thickness of these lateritic beds spread throughout the Hazara and Kohat-Potwar plateau. This hematite ore exists in the form of unconformity. X-ray diffraction technique (XRD), X-ray fluorescence spectrometry (XRF), detailed petroghraphic study and scanning electron microscope (SEM) techniques indicated that those iron bears minerals including hematite, chamosite and quartz, albite, clinochlore, illite-montmorillonite, kaolinite, calcite, dolomite, whereas ankerite are the impurities present in these beds. The X-ray fluorescence (XRF) results show that the total Fe2O3 ranges from 39 to 56%, with high silica and alumina ratio of less than one. Beneficiation requires for significant increase in ore grade. The petroghraphic study revealed the presence of ooids fragments as nuclei of other ooids with limited clastic supply, which indicate high energy shallow marine depositional setting under warm and humid climate. The overall results show that Langrial Iron Ore is a low-grade iron ore which can be upgraded up to 62% by applying modern mining techniques so as to fulfill steel requirements of the country.

Reduction Kinetics of Fine Hematite Ore Particles in Suspension

Suspension reduction kinetics of hematite ore particles at 1710 K to 1785 K was described by the Johnson-Mehl-Avrami-Kolmogorov model with Avrami exponent of 1.405. The apparent activation energy is 105.5 kJ mol−1 with the rate determining step of nucleation and growth. The reduction degree of the hematite at the endpoint is a linear function of temperature and the logarithmic oxygen potential of the reacting gas. A peak function of reaction rate constant with particle size has been verified in this work, and the maximum value of the reaction rate is located at around 85 µm particle size. The influence of heat transfer on the reaction process has been evaluated. The results suggest that the heating-up process for large particles, 244 µm particles, for instance, cannot be ignored. It can retard the reaction rate compared to small particles. Normally, the reaction rate constant decreases linearly with the increase of ln[p(O2)] of the reacting gas mixture. However, 95 vol pct CO2 in the reacting gas can accelerate the reaction rate of thermal decomposition of hematite due to the emissivity of CO2 gas. It results in a higher reaction rate of 110 µm particles in 95 vol pct CO2-containing gas than that in other less CO2-containing gases.

Characterization and mapping of hematite ore mineral classes using hyperspectral remote sensing technique: a case study from Bailadila iron ore mining region

The study demonstrates a methodology for mapping various hematite ore classes based on their reflectance and absorption spectra, using Hyperion satellite imagery. Substantial validation is carried out, using the spectral feature fitting technique, with the field spectra measured over the Bailadila hill range in Chhattisgarh State in India. The results of the study showed a good correlation between the concentration of iron oxide with the depth of the near-infrared absorption feature (R2 = 0.843) and the width of the near-infrared absorption feature (R2 = 0.812) through different empirical models, with a root-mean-square error (RMSE) between < 0.317 and < 0.409. The overall accuracy of the study is 88.2% with a Kappa coefficient value of 0.81. Geochemical analysis and X-ray fluorescence (XRF) of field ore samples are performed to ensure different classes of hematite ore minerals. Results showed a high content of Fe > 60 wt% in most of the hematite ore samples, except banded hematite quartzite (BHQ) (< 47 wt%).

Dephosphorization behavior of reduced iron and the properties of high-P-containing slag

Reduced iron (1.74% P) is produced from oolitic hematite ore by coal-based reduction and magnetic separation. To realize the comprehensive utilization of Fe and P, the dephosphorization behavior of the reduced iron is investigated in the presence of CaO–SiO2–FeO–Al2O3 slag. The P content of the final iron and the P2O5 content of the high-P-containing slag are determined, and the phase composition and P2O5 solubility of the slag are analyzed. The P content can be decreased to 0.2% when the initial slag has a basicity of 3.5 and contains 55% FeO and 6% Al2O3. The phases of the high-P-containing slag are mainly Ca2Al2SiO7, Ca2SiO4, Ca5(PO4)2SiO4, and FeO, and P exists in the form of Ca5(PO4)2SiO4. Excessively high basicity or low content of FeO and Al2O3 results in free CaO, which affects the dephosphorization results. The change rule of the intensity of the Ca5(PO4)2SiO4 diffraction peak agrees well with the dephosphorization indexes, which further verify the accuracy of the dephosphorization experiments. Moreover, the P2O5 content and P2O5 solubility of the high-P-containing slag reached as high as 14.41 and 94.54%, respectively, indicating that it can be used as a phosphate fertilizer.

Development of Concentration Technology for Medium-Impregnated Hematite Quartzite of Kryvyirih Iron Ore Basin

Introduction. Trends in developing Ukraine’s metallurgy in the context of using its mineral raw base indicate prospects for mining hematite quartzite deposits. Problem Statement. The problem of producing high-quality hematite ore concentrates is associated with the fact that aggregates of martite, goethite, marshallit quartz, and other low hard minerals can be easily reground while crushing and grinding. This results in increased content of fine particles (slimes), which decreases selectivity of separating ore and non-metallic minerals. One of the ways to solve this problem is gentle ore grinding Purpose. Developing a technology of dry and wet concentration for hematite quartzite from Kryvyi Rih Iron Ore Basin. Materials and Methods. While conducting the research, a set of methods are used including generalization of research data; chemical and mineral analysis of ore and concentration products prior to and after concentrating by magnetite and gravitation methods; mathematical modeling of processes; technological testing in laboratory and industrial conditions. Results. Magnetic and gravitation separation is used for hematite ore concentration. Sintering ore with Fe content of 55.1% and concentrates of 62.32-64.69% Fe have been produced from hematite ore. Iron extraction in marketable products makes up 73.6-80.49%. Conclusions. There have been developed technologies for dry and wet concentration for hematite quartzites of Kryvyi Rih Iron Ore Basin. For the first time, magnetic separation has been suggested to be used for hematite ore concentration. This has enabled producing concentrates with an iron content over 64.0%, decreasing ore grinding front by at least 40% as compared with the initial one, and reducing operation and capital expenses by over 30%.