This article reports on a molecular dynamics simulation-based research that investigates the adsorption of sodium oleate (NaOl) on the of the highly hydrophilic 001 hematite surface in froth flotation and its effect on the mineral's wettability properties. The molecular dynamics simulation was conducted using LAMMPS. The wettability properties were evaluated by comparing the thermodynamic characteristics of two surfaces, one net and the other coated by the collector. Surface energy, center of mass location of water molecules, water density in contact layers and adjacent to the surface, and fluid permeability coefficient were used as indicators of wettability. The simulation results showed that the 001 surface of hematite is highly hydrophilic due to strong electrostatic interactions and feasible hydrogen bond formation sites. However, with the adsorption of the collector, the surface became hydrophobic due to a sharp decrease in surface tension, reduction of intermolecular interactions, and loss of hydrogen bond formation sites. The results confirm that the selective absorption of the collector on the hematite surface enables its floatability.

In this study, for gypsum and hematite minerals separating from kaolin, the floatation technique that it's selective separation rate is very high, has been used. The effect of three factors; pulp conditioning time, pH and kind of collector, has been considered. All of experiments has been carried out by using cationic collectors (amines), in alkalin environment (pH range between 10.5 to 12.5) and pulp conditioning times of 4, 6, 8 and 10 minutes. The results of chemical analysis of before and after floatation samples, has been compared and the rate of separating capability of gypsum and hematite from kaolin has been defined.

a-Fe2O3 (hematite) nanoparticles were synthesized using tragacanth gel as biotemplate and iron chloride as the iron source by the sol-gel method. This method has many advantages such as nontoxic, economic viability, ease to scale up, less time consuming and environmental friendly approach for the synthesis of a -Fe2O3 nanoparticles without using any organic chemicals. Nanoparticles were characterized by Fourier transform infrared (FT-IR) spectroscopy, UV-visible spectroscopy and X-ray diffraction (XRD). The powder X-ray diffraction (XRD) analysis revealed the formation of Rhombohedral phase a-Fe2O3 with average particle size of 21 nm.

In the present work, the effect of aluminum on mechanical activation of hematite graphite- aluminum mixture has been investigated. Various amounts of aluminum powder (0 to 10 wt%) was added to hematite-graphite mixture (C/O=1 or 18.40 wt% graphite). Then, the mixture was mechanically treated by means of ball milling within different time periods, from 0 to 10 hours. XRD and SEM tests were carried out to study the effect of aluminum and milling time on activation mechanism of the mixture. It was found that existence of aluminum particles, as formable material, in the brittle hematite-graphite mixture could influence on the microscopic condition and subsequently on the behavior and intensity of mechanical activation of the mixture.

Hematite (α,-Fe2O3) nanoparticle was synthesized using organometallic compound-ferrocene carboxaldehyde through solventless solid state thermal decomposition technique. The crystal structure, magnetic and morphological properties of the decomposed material were studied using powder X-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, 57 Fe Mö, ssbauer spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) techniques. Structural study confirmed that the synthesized material is hematite with hexagonal phase and good crystallinity. The temperature-dependent magnetization measurement exhibited the Morin transition-the yardstick for hematite formation. Mö, ssbauer spectroscopic study confirmed the purity of phase of the synthesized material. The SEM study observed mostly the agglomerated tiny particles along with some ring-shaped surface structures. The TEM study of the synthesized material showed that the highest distribution of the particles with ~5 nm size. The observed EDX spectra confirmed the existence of Fe and O in the synthesized material. The solid state reaction process leading to hematite on decomposition of ferrocene carboxaldehyde has also been proposed. Present study describes a simple process for the preparation of pure hematite nanoparticle by solventless method.

This study was carried out to obtain the optimal mechanism and conditions for the separation of fine particles (-38 µ ) of quartz (float) from hematite (depression) by direct carrier flotation. In this study, first, the type and size of carrier particles were determined to adsorb pure quartz particles on the surfaces of these particles. Then, the effect of various factors such as the type and concentration of collector and pH on floating particulate matter on the carrier particles was investigated using several experiments. In order to select carrier particle, the effect of pyrite and calcite on the selective collection of quartz particles was tested. According to the results of experiments, calcite particles in the size of (+75 – 106) micron were selected as suitable carriers for the adsorption and collection of fine quartz particles and then their floating. It was also found that the preparation of calcite particles with the collector, before adding them, had a positive effect on the adsorption of fine quartz particles. Experiments showed that the best conditions for calcite particles to float at pH = 11. 5 with presence of dodecyl amine collector at a concentration of 1. 5 kg / ton. After investigating the effect of process variables on the responses obtained, optimization of the operating the aim was to maximize grade and recover quartz in the flotation float concentrate. In the optimum condition, carrier size (+75-106) micron and amount of 34% quartz was obtained. The optimum results showed that the quartz recovery in the concentrate was about 71% and its grade about 81% of a synthetic feed with a ratio of 40% hematite and 60% quartz.

Objective(s): Albuminuria is a biomarker in the diagnosis of kidney disease which is due to the presence of high albumin in the urine and is one of the complications of diabetes. In recent years, the methods used to identify albuminuria have been expensive and time-consuming. Furthermore, another problem is the lack of accurate measurement of albuminuria. This problem leads to kidney isolation as well as a decrease in erythropoietin levels. Therefore, the main aim of our work is to design a magnetic nanobiosensor with better sensitivity to detect minimal levels of albuminuria. Materials and Methods: In the present work, we synthesized Hematite Nano Rods (HNRs) using FeCl3, NaOH and Cetyltrimethylammonium bromide (CTAB) precursors via the hydrothermal method. Then, HNRs were characterized using UV-vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Vibrating Sample Magnetometer (VSM) techniques. Results: The obtained results from clinical performance of the HNR nanobiosensor show that the magnetization changes of HNR in interaction with the albumin biomarker can determine the presence or absence of protein in biological samples. The accuracy and repeatability of the HNR nanobiosensor from the value of the R2 coefficient in the standard equation is 0. 9743. Conclusion: We obtained the standard curve through interaction of the HNRs with albumin protein. The standard equation is obtained by plotting the magnetization curve of a non-interacting sample to interacting samples in terms of protein concentration. The Bland-Altman statistical graph prove that the HNR nanobiosensor is as reliable as experimental methods.