A roast experiment was carried out by using vanadium stone coal from Hubei Province as object, in the condition of compound additive dosage is 6%, the effects of roasting temperature, roasting time and material size on vanadium lixiviate efficiency were investigated. Experimental results indicate that, for the vanadium stone coal from Hubei Province, at the condition of additive dosage is 6%, the ideal target of vanadium lixiviate efficiency 82.3% can be acquired in the optimum condition of roasting temperature at 850 oC, roasting time is 120 minutes, material size is minus 0.5mm.

There are plentiful of oolitic iron ore resources on the earth, which cannot be currently exploited because of great difficulties for beneficiating the ore. In this work, the selective fragmentation of a Chinese oolitic iron ore (which fragments ore particles along the interfaces of iron and gangue minerals) through microwave was studied in order to liberate the iron minerals at a coarse particle size and thus to effectively concentrate the iron minerals from the ore. The experimental results have shown that a large amount of fractures on the oolitic iron ore were formed along iron and gangue mineral interfaces after being treated by microwave radiation at an appropriate frequency and potential. Following a microwave treatment, the oolitic iron ore was ground by using a ball vertimill. It was indicated that the pretreatment increased the liberation of the iron and gangue minerals at the same particle size, about 10-20% and 10-30% respectively.

The cyanide is the main process for the extraction of gold from its ores. This process produces rich cyanide solutions containing gold and silver, and waste cyanide solutions with different metal compounds such as copper, zinc and iron. These elements or compounds can be extracted in the form of high-value compounds as nanoparticles. This work presents some result of the remove and recovery of metallic values from waste cyanide solutions to obtain novel metallic nanoparticles. These materials were obtaining by modified sol-gel method from an industrial cyanide waste solution previously treated by advanced oxidation. This work reports the characterization from the nanoparticles by DRX and SEM-EDX. The results indicate that multimetallic nanoparticles can be obtained from cyanidation effluents.

Stone coal is an important vanadium-bearing resource in China. Most vanadium exists in stone coal as V(III), which is stable and not easily to be extracted. The V(III) should be oxidized to V(IV) and/or V(V) by roasting with additives at high temperature and then extracted by acid leaching and/or water leaching. Hence, the vanadium valency in roasted stone coal can reflect the roasting efficiency and leaching rate. In traditional digestion process, the V(V) can oxidize V(III) in solution and this causes great error to the determination of vanadium valency. In this study, the V(IV) and V(V) in roasted stone coal is dissolved firstly in 5% of hydrochloric acid at room temperature for 1h because the V(III) embedded in crystal lattice can not dissolve in dilute acid. The acid solution containing V(IV) and V(V) is titrated by 0.02 M ammonium ferrous sulfate (AFS), and the jump in titration curve indicates the reducing of V(V) to V(IV) by ferrous ion. The volume of V(V) can be calculated according to the consumption of AFS. The total volume of vanadium can be determined by potassium permanganate oxidation-ammonium ferrous sulfate titrimetric method. Hence, the volume of V(IV) can be obtained by deducting the quantity of V(V) from the total vanadium. Secondly, the undissolved residue is digested in Teflon vessel by phosphoric acid and hydrofluoric acid at 90 °C for 2h. The digestion solution is also titrated by AFS under nitrogen atmosphere, and the jump in titration curve denotes the reducing of V(IV) to V(III) by ferrous ion in phosphoric acid medium. So, the volume of V(III) and V(IV) can be obtained in the same way. This method is characterized by high measuring accuracy and excellent reproducibility.

The present work describes a patent applied for registration at the IMPI (Instituto Mexicano de la Propiedad Industrial) of a production process of zeolite X using as raw materials alum sludges issued from drinking water treatment plants. Sludge sample was collected in a water drinking plant located northern Mexico City. The sample was dried and then physicochemical and microbiological analyses were carried out (metal content, main oxides content, mineralogical analysis, helminth eggs content, fecal coliforms). In accordance with its characterization, two main steps of the zeolites production process were performed: 1) alkaline fusion of alum sludge-NaOH mixture for increasing the dissolved precursor’s content and 2) alkaline hydrothermal treatment. Spherical particles of zeolite X were identified by SEM and XRD respectively. The best synthesized zeolite showed a CEC=2.11 meq/g, value being similar to the data reported for clinoptilolite (the most commonly zeolite used for water treatment in the removal of heavy metals). Thus, the synthesized zeolite X in this work can be used for the same purpose.

Direct ultrasonic vibration (DUV) method by dipping the horn into the melt can be used to make semi-solid metal slurry, but application of this process is embarrassed because of the erosion problem of titanium-alloy horn by aluminum melt. In order to avoid this problem, a slurry-making process with indirect ultrasonic vibration (IUV), in which the horn is vibrated under the outside of the metallic cup containing alloy melt, has been developed in this research. Semisolid slurry of A356 Al alloy was prepared by this process, and the effects of IUV treatment time on the morphology of the primary α-Al phase and mechanical properties of rheo-diecasting samples were studied. The results indicate that excellent semisolid slurry of A356 Al alloy could be obtained within 50s by applying IUV near its liquidus temperature, and the average diameter and shape coefficient of the primary α-Al particles were 75μm and 0.62, respectively. IUV treatment time had a significant effect on the mechanical properties of the rheo-diecasting samples, and samples treated by IUV for 50s had the maximum tensile strength and elongation. The maximum as-cast tensile strength and elongation were 244MPa and 7.5% respectively, which were increased by 10% and 75% respectively compared to conventional molten-melt die-casting samples. In addition, the mechanism of preparing semisolid slurry of A356 Al alloy by IUV is discussed.

Wastewaters often contain offensive cations. Because of their high affinity for water, it is difficult to remove those using conventional solvents for liquid- liquid extraction [1]. Hydrophobic ionic liquids may provide a useful extraction process. Because the properties of ionic liquids are turnable, it may be possible to identify some ionic liquids that have low viscosity, very low solubility in water, and high affinity for select metal ions [2]. In this sense in this work liquid- liquid extraction of dilute Zn ions from water was performed near room temperature with two ionic liquids (IL). Distribution coefficients are reported for Zn ions extracted with bromide 1-hexyl-pyridinium and bromide 1-octyl-pyridinium diluted in decanol. The extraction has been studied, and these confirmed that the metal extraction proceeds via a cation – exchange mechanism. Furthermore, stripping of Zn (II) from ILs into an aqueous phase by sulfuric acid (1 M) and recycling of the extracting ILs phase was successfully accomplished.

Dust originated from the iron and steelmaking containing undesirable compounds are not completely recycled because affects the process efficiency. These types of dust represents an economical lost as a consequence of values contents. However, dust have been characterized physically and chemically in order to study their potential environmental applications, as the removal of arsenic in wastewater. The results shows that dust have a superficial specific area between 16 and 20 m2/g, values considered high, typical of a material with adsorbent properties. Representative results of different tests adsorption of arsenic in the material described indicate that it is possible to reduce the arsenic levels in up to 95% from an initial concentration of 1 mg/L of total arsenic. The results indicate that the iron and steelmaking wet dust may represent a new option as material for the removal of heavy metals in water treatment.

Kaolin is an important material that is used in industrial applications, including ceramics, paper, paints, fiberglass, inks, pharmaceuticals, and cement. The presence of impurities, particularly iron and titanium bearing materials, imparts color to kaolin. During weathering or hydrothermal alteration, significant levels of iron oxides can be deposited that leave a concentrated kaolinitic clay unusable for industrial application. Therefore, several chemical methods have been applied to kaolin beneficiation in order to reduce these contaminants. Ferric oxide dissolution is of particular interest for producers of industrial minerals such as kaolin. The objective of this work was to examine the kinetics of iron dissolution form low grade kaolin using oxalic acid solutions. The effects of acid concentration and reaction temperature were studied. It was determined that the iron dissolution rate increases with oxalic acid concentration, temperature. Leaching data showed that iron dissolution from low grade kaolin is due to diffusion through the product layer. The activation energy of the process was 46.32 kJ/mol.

In this work we present new experimental results about the packing fraction of a granular monolayer excited by taps in the gravity direction. The role of large amplitude of tapping is discussed. Also, the relationship between packing fraction and the number of particles in the sample is analyzed.

Full automation of electron microscopy is now a mature technology that is being applied internationally mainly for mineralogical characterization. This technology has increased the speed and reliability of the characterization of ores and mineral processing products. It allows developing the most appropriate beneficiation technology for a new ore body. It helps to determine the potential, the optimization and the limitations of mineral concentrator plants. It can also be applied to the betterment of the environmental management of the metallurgical residues. This presentation will discuss the main approaches for fully automated electron microscopy. Additionally, an application case is presented, focusing on the characterization of complex ore of rare earth minerals.

A method, based in leaching with SO2, to process low grade pyrolusite minerals has shown good results at laboratory scale. After the separation of the solid impurities, the dissolved manganese is subsequently precipitated using the SO2/O2 gas mixture as oxidising agent. In this research it was obtained a mathematical model to estimate the oxidative precipitation process, as a function of temperature, pH and SO2 gas flow rate. It was found that pH and temperature have the main influence in the reaction rate. An optimal SO2 concentration in the mixture must be used to avoid generation of reductive conditions. It was observed a most efficient reaction with a low gas flow rate injection. The predicted reaction rates presents a good concordance with the experimental results (R2=0.97), showing a worthy potential for practical uses.

An identification of the characteristics of microbbubles dispersion is presented in this paper, when frother addition (MIBC) is modified in a biphasic system (air-water). Sauter diameter (d32), gas flow rate (Jg), superficial area flow density of the microbubbles (Sb) and air holdup (εg) are the measured variables in this research work. The studied frother additions were 0, 10 and 20 ppm. Similar to conventional bubble sizes, it was observed also, that air holdup increases with the air flow rate. The linear relationship between εg and Sb permits to conclude that superficial area flow density, a variable difficult to measure directly, may be estimated if air gas holdup is known. Furthermore, the experimental results showed that frother addition (MIBC) reduced the Sauter diameter, increasing all other variables.

With the impending depletion of mineral resources and a worsening environment, the need to enhance energy efficiency and reduce emission of CO2 gas has become a serious global issue. This paper discusses the current condition of metallic ore resources, then lays emphasis on the counter measure of metallic materials processing. The principal metallic materials are iron and aluminum, and in the scrap of these materials there contains metallic resources and deposited huge energy. Through the recycling of the scrap metal, we can reduce the energy consumption on the extraction of these materials and decrease the emission of CO2 gas. The energy consumed in manufacturing products by using reclaimed raw aluminum is only 4.9% of that using new raw materials, and as for iron and steel, the data is 40.7%. In the manufacturing of metal components, while the impurity element content is rigorously restricted in the plastic forming method, the casting method has a much larger permissible range. Thus, remelting and casting is a more appropriate method in the recycling of metallic materials.

At present, the industrial sector requires the recovery of tool steel components subjected to severe wear which are built with steel HWS these have the same properties in all tribology directions and have great success in building tooling. In this paper, we recover the previously HWS steel machining with a fillet of 2mm caused by the metallurgical recovery of the component, applying the process of plasma transferred arc PTA which has very good fats dilution properties in comparison to other conventional processes currently applied for the recovery of tooling, such as GTAW, SMAW, SAW. The experiment was conducted with input D2 and M2 with one and two welding seams, making the assessment metallography, hardness and wear tests pin-on-disk. Finding a decrease in the hardness of the interface line, according to the evaluation of wear pin-on-disk, had a higher wear rate of the filler metal in the M2 D2.

In a highly dispersed flotation pulp, ultrafine hydrophilic minerals can entrain into froth products even though they may be perfectly hydrophilic. Therefore, effective depression of the hydrophilic minerals in froth flotation relies not only on rendering the minerals hydrophilic, but also on proper particle size control. In this paper, it will be shown that several depressants in mineral flotation systems indeed not only make the minerals hydrophilic but also cause selective coagulation or flocculation of the hydrophilic minerals. As a result, both the genuine flotation and the hydraulic entrainment of the hydrophilic minerals are reduced. The aforementioned depressants and mineral flotation systems include: zinc sulfate in the depression of sphalerite while copper sulfide and lead sulfide are floated; starch in the depression of iron oxides and phosphates while quartz is floated; polyethylene oxide in the depression of quartz while sulfide minerals such as chalcopyrite is floated.

Therefore, in fine and ultrafine particle flotation, the flotation depressants should be able to not only make the to-be-depressed minerals hydrophilic, but also make them selectively aggregate.

Vanadium-beard bone coal is one of important vanadium resources in China. to extract vanadium tailings from Stone coal is prduced after extracted vanadium from stone coal through the roasting, leaching and other processes. About 120-150 tons of tailings will be produced in extracting 1 ton of vanadium pentoxide. A lot of tailings that are willfully piled up have caused serious environmental pollution and wasting of resources; it is therefore necessary to realize its resource utilization. This study increases the activity of vanadium tailings by means of alkali fusion, and then uses different alkali activators to react with vanadium tailings so that geopolymer with high value added is produced. Sample of geopolymer is acquired from mixture containing vanadium tailings, alkali activators, water and a little sodium aluminate through compression-molding process under 20MPa pressure. After cured in room temperature for three days, the maximum compressive strength of the sample can reach 36.2MPa. XRD analysis indicates: quartz, the major crystal phase in vanadium tailings is decomposed and the activity of vanadium tailings is heightened. FTIR and SEM analyses show: structural change having important impact on the mechanical strength of geopolymer occurred during the process of vanadium tailings generating geopolymer.

Coal deposits in Mexico were firstly recognized back in 1850, the main coal deposits in Mexico are located north of the Coahuila State. Coal samples from coal mines of Sabinas Basin were collected and analyzed for chemical composition, separation characteristic and calorific value (CV). The analytical data indicate that the coals usually have low or high ash content (Ash), 17 – 50 wt %, depending on the sample source. Comparison of the calorific value with both ahs content and fixed carbon, indicate that these two parameters are directly connected together: the higher the calorific value of coal, the lower the ash content and high fixed carbon content. Rejection of the ash using sink-flotation technique and their ratio whit the calorific value (CV/Ash) was evaluated in this study. Also, the ratio of Calorific value to fixed carbon (FC) was analyzed. Washability analyses for selected coal sample (+1 ½”, -1 ½” + ½”, -½” +¼“, - ¼“ + 1/16”, -1/16” +#100, size group) using heavy organic liquids with a density from 1.3 to 1.6 gr/cm3, were carried out. Calorific value-ash (%)-Fixed Carbon relationship was presented. The results indicate that the ratio CV/Ash vs. specific gravity has an exponential behavior, whereas the value of the ratio CV/FC was found to be 117.3.

Lead is an engineering material used mainly in the manufacturing of lead-acid batteries for the automotive industry. Lead recovery from exhausted batteries is carried out by the pyrometallurgical route by injecting sulfur the powder reagent through a lance into the lead bath. In this work a mathematical simulation was carried out on the copper drossing process with the software COMSOL 3.4. A kinetic study of the injection process of the lance-kettle system was carried out. The copper concentration profiles were obtained according with the injection rate of the particles. The best conditions for the copper drossing process were an injection rate of 3.31 m/s at 380°C. The modeling results were validated with experimental results obtaining good agreement.