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By Dachun Liu, Xuepeng Li

Smelting-acid leaching process is a way to treat high-content arsenic containing copper dust. However, smelting makes a low recovery of valuable metals and acid-leaching produces large amounts of arsenic-iron slag. Arsenic sulphuration volatilization at low temperature was studied, followed by pressure leaching to selectively recover Cu, Zn, and In from copper smelting dust while minimizing arsenic contamination.

Mar 1, 2017

By Alastair Torrance, Gary Cavanough

Approximately 1.5 million tonnes of ammonium nitrate are transported annually across Queensland, Australia—equivalent to nearly 100 truckloads per day. This is in the form of both AN prill and ammonium nitrate based emulsions (ANE). In a recent incident, a collision involving an ANE tanker resulted in a detonation that caused extensive blast-related damage and led to the closure of a major highway. Had this event occurred within a populated area, the consequences would have been catastrophic. For over a century, investigations into the causes of such spontaneous detonations have been inconclusive. A recently completed industry supported research project has made a pivotal discovery: a surface reaction mechanism leading to hydrogen generation has been identified as a precursor to detonation. If sufficient hydrogen accumulates and subsequently ignites, it can release enough energy to initiate the detonation of bulk ammonium nitrate and ANE. Controlled experiments conducted during the project successfully demonstrated hydrogen-driven detonation events. Previous work by Proulx and Scovira, presented at the 2000 ISEE Conference, described spontaneous detonations in hot, reactive ground and the mitigating effects of buffered emulsions and ANFO. Building upon their observations, this study reproduces similar incidents under laboratory conditions, confirming that hydrogen generation also results from reactive ground interactions. Importantly, the findings challenge traditional assumptions, demonstrating that ammonium nitrate and ANE detonation in reactive environments does not require an ignition temperature threshold, confinement, or a classical chemical decomposition pathway.

Jan 26, 2026

By Galetakis M., Deligiorgis B., Xiroudakis G.

Fragmentation prediction is important in surface mining to optimize downstream processes such as loading, hauling, comminution, and beneficiation processes. Traditional approaches, such as the Kuz-Ram model, image-based fragmentation analysis, and numerical simulations, rely heavily on large datasets acquired after blasting. Moreover, due to the inherent limitations in each method there is an underestimation of fine and coarse fragment sizes, when applying these models without prior knowledge regarding the fragmentation distribution. These drawbacks are restricting their use only in post-blast parameter prediction. In response to these inefficiencies, this study presents a deterministic fragmentation prediction methodology based on a single-blasthole model. The model simulates the formation of the damage zones around a blast hole based on the number of cracks within a distance from the centre of the blast-hole and correlates them with an estimated fragment size in each domain. A fragmentation distribution from the literature is employed to validate the proposed approach and the results are compared with those generated using a modified Kuznetsov model. This approach aims to enhance blast design decisions by enabling pre-blast fragmentation prediction. Based on this, blast designs could be estimated depending on the desired fragmentation before blasting, giving the opportunity for a tailored to local rock properties optimization.

Jan 26, 2026

By Wei Han, Zhenwei Liu, Jianhong Yang, Qingwei Qin, Tiejun Chen, Zili Huang

The preparation of industrial ammonium molybdate from molybdenum concentrate was conducted according to the process of roasting—leaching—purification—precipitation—crystallization. The optimum technological conditions were determined: the roasting temperature was 680 degrees C, the roasting time was 2.5 h; in the leaching process the alkali excess coefficient was 1.2, the reaction temperature was 80 degrees C, the liquid-solid ratio was 3:1, the leaching time was 3 h; the amount of (NH4)2S added into the solution was 1.1 times of the theoretical amount, the temperature was 80-85 degrees C, and the terminal pH was 8.5-9 in the purification process; the density of the solution was 1.4-1.6 g/mL, the pH was 1.5-2 in the precipitation process; temperature of dissolution was controlled at 80-90 degrees C. The recovery of the preparation of ammonium molybdate can reach 85.18%.

Mar 1, 2017

By Ping Long, Peipei Liu, Xinlin Ren, Yunke Wang, Bin Yang, Jian Wu, Wenli Zhang

In this research, ICP-AES was used for determining ten impurity elements (Fe, Pb, Ca, Mg, Cu, Zn, Al, As, Sb, and Bi)in tin concentrate and smelting products, such as crude tin and slag. Samples were dissolved by hydrochloric acid and nitric acid. Determination conditions were investigated in detail. Influences of matrix and coexisting elements were eliminated by selecting proper analysis spectral lines. Under the optimum conditions, the correlation coefficient of cali- bration curves were higher than 0.999. The detection limits of these ten impurities were in the range between 0.0009 to 0.0621 lg/ml. Relative standard deviation (RSD) values were lower than 6.0%, and the recoveries of standard addition were between 85 and 109%. The proposed method was demonstrated to be reliable by comparingwithstandardanalysismethodsandcertifiedvaluesofstandardsample. It could be applied for determining impurity elements in tin concentrate and smelting products successfully.

Mar 1, 2017

By S. L. I. Chan, M. Z. Quadir, D. C. Austin, P. J. Hazell, A. Chen, A. A. H. Ameri, D. East, J. P. Escobedo, M. A. Bevan, A. D. Brown

The microstructure and mechanical response of additive manufactured Ti64 under compression and tension has been investigated. Quasi-static and dynamic experiments were conducted on electron beam powder bed Arcam A1 (EBM) and blown powder laser Optomec LENS MR-7 (LMD) additive manufactured specimens. Hot isostatic pressing (HIP) was conducted on both of the additive manufactured specimens and results were compared with as-received specimens. Digital image correlation (DIC) was utilized to observe the in situ development of deformation fields during tensile loading. Optical microscopy was conducted on pristine and deformed specimens to examine the microstructure of the specimens. HIP treatment reduced the porosity by *90% with a concomitant increase in hardness by 40%. The results from tensile experiments show that additive manufactured Ti64 display a higher values for the yield stress, hardness, and ultimate tensile strength than conventionally manufactured Ti64. Under quasi-static compression, it was observed that EBM specimens exhibit a higher yield strength and ultimate tensile strength than LMD specimens.

Mar 1, 2017

By Raj K. Rajamani, James R. Nagel, York R. Smith

In this work, we examine the efficacy of Electrodynamic Eddy Current Separation (EECS) to recover valuable materials from end-of-life solar panels. Traditional rotary-based eddy current separators are capable of excitation frequencies of 1 kHz or less and struggle to economically separate particles smaller than 1 cm. A new design of eddy current separators has been developed at the University of Utah which has no mechanically moving parts. The design is capable of excitation frequencies up to 50 kHz, allowing sorting of particles as small as 1.0 mm. Recently, we have been successful in separating mixtures of Si/Al and CdTe/Al particles (1–3 mm) with recovery and grades greater than 85%, an energy demand of 68 kWh/short ton of sorted material, and throughput of roughly 10 kg/h. Current and future challenges utilizing this method for valuable material recovery from end-of-life solar panels are discussed.

Mar 1, 2017

By Esperidiana A. B. Moura, Elizabeth Carvalho L. Cardoso, Glauson Aparecido F. Machado, René R. Oliveira

Plastics global annual production exceeds 250 million tons and more than 40% of the total plastic production is used as packaging materials. In recent years polymeric materials derived from biomass have received great attention due to scarce petroleum resources and environmental concerns. PLA is one of the most extensively studied bio-based and bio-compostable aliphatic polyesters; nevertheless, high brittleness and low toughness limits its application. Blending PLA with PBAT (Poly(butylene adipate-co-terephthalate)), an aliphatic-aromatic copolyester, was the solution found due to its high toughness and biodegradability. Differences between PLA and PBAT solubility parameter values lead to the formation of immiscible blends as well as reduction in their mechanical performance besides a poor morphology; so, 5% of pre-irradiated PLA and a previous compatibilized PLA/PBAT (EcovioTM) were added to PLA/PBAT blends in order to improve miscibility phases. Investigations were accomplished on phase morphology (SEM), mechanical properties, thermal behavior and X-ray diffractions (XRD).

Mar 1, 2017

By Jingtao Wang, Xiaoyu Han, Jun Bao, Wei Hou

Lightweight stainless steel has widely potential applications in many fields, such as automobile, ship, submarine manufacturing and aerospace. The properties of lightweight stainless steel are significantly affected by the precipitating behaviour of second phase particles. In this paper, the precipitating behaviour was investigated by XRD, DSC in the process of heating and thermodynamic calculation combining the Miedema’s and Chou’s model. The XRD results indicate that there are five types of phases in lightweight Fe–Mn–Al–C–N stainless steel: ferrite, FeAl, AlMn, AlN and Mn4N. The DSC results show that the precipitating temperature of FeAl, Mn4N is 1260, 1031 °C, respectively, corresponding to the thermodynamic calculation. Besides, The DSC measurement reflects the precipitating temperature of AlMn and austenite is 934 and 600 °C.

Mar 1, 2018

By Lilong Zhu, Shaoda Zhang, Qian Wang, Shengping He

The effects of ZrO2, Y2O3 and Sc2O3, which are transition metal oxides, on the melting temperature, viscosity at 1300 °C, and break temperature of three mold fluxes (two weak-reactive type and one non-reactive type) designed for the high manganese and high aluminum steels, and one another conventional CaO-SiO2 based mold flux is studied. The results indicate that the melting temperature and viscosity increases slightly, and the break temperature increases dramatically with the addition of ZrO2, Y2O3 and Sc2O3 content in the conventional CaO-SiO2 based mold flux system. While, the addition of ZrO2, Y2O3 and Sc2O3 in the weak-reactive or non-reactive mold flux systems has a negligible in fluence on the melting temperature, viscosity and break temperature, suggesting that these transition metal oxides are possible to regulate radiation heat transfer without changing the basic properties of mold fluxes.

Mar 1, 2018

By Xueming Lv, Xuewei Lv, Jie Qiu, Lunwei Wang

Non-isothermal multiple scanning rate analysis method was used to analyse the solid-state reduction of nickel laterite by carbon. According to the TG curves, the activation energies were calculated and the most probable mechanism functions were determined by the Malek method. The results show that the process can be divided into three stages according to the reaction degree (a): 0–40%, 40–70%, 70–100%, respectively. In the stage of 0 a 0.40, the most probable mechanism function fits the chemical reaction order function. In the stage of 0.40 a 0.70 and 0.70 a 1.0, the process may not be exactly described by one mechanism function.

Mar 1, 2017

By Ying Qin, Shujing Zhu

The characterization of adsorption of natural and composite bentonite in lead aqueous solution has been studied. The results showed that adsorption of both natural and composite bentonites strongly depended on the pH values of the solution. At lower pH values, the mechanisms that govern the adsorption of bentonites were dissolution of crystal structure and competition between the metal ions and the H+. To composite bentonite, the lead ion removal capacity was close to 250 mg/g. At higher pH values, formation of lead hydroxyl species might lead to either participation to the adsorption or precipitation onto the bentonites. Hence, a rapid increase in the equilibrium removal capacity of lead was obtained when pH > 7.0. An increase in the initial lead ion concentration led to the increase in the equilibrium adsorption capacity increased to a certain degree; and then, a plateau was obtained at higher concentrations. As a result, the adsorption performance of composite bentonite was better than the natural bentonite in both physical and chemical changes. The data fitted well with both Langmuir and Freundlich isotherms.

Mar 1, 2017

By H. Y. Sohn, Y. Mohassab, D. -Q. Fan, M. Elzohiery, A. Abdelghany

The Flash Ironmaking Technology being developed at the University of Utah is aimed at producing iron directly from iron oxide concentrate. In this technology, the concentrate is reduced by H2 and CO gas mixtures formed from the partial oxidation of natural gas in a flash reactor. Natural gas represents an economically and environmentally superior reductant/fuel for the flash ironmaking. The rate equations for the reduction kinetics by H2, CO and H2 + CO gas mixtures were determined in the temperature range 1150–1600 °C. These rate equations were applied to experimental results from a laboratory flash reactor using Computational Fluid Dynamics CFD simulation. A new mini-pilot reactor, which is capable of operating at 1150–1550 °C with a concentrate feeding rate of 2–5 kg/h, has been installed. Commissioning of the reactor with an emphasis on preheating of the reactor, production of reducing gas mixtures and the feeding and collection of iron ore concentrate and product particles has been completed.

Mar 1, 2017

By J. A. S. Tenorio, K. S. Barros, D. C. R. Espinosa

Considering the risks involving the use of cyanide, other complexing agents have been evaluated for the treatment by electrodialysis of the effluent of brass electrodeposition and among them, EDTA is interesting since it has been already tested for many years to separate ions. The main objective of the present paper was to evaluate the occurrence of fouling and scaling on the surface of the anion-exchange membrane HDX 200 by the construction of chronopotentiometric curves and speciation diagrams in different conditions (pH between 10–12 and proportion of cupric ions of 30%, 50%, 70%). According to the results, the chronopotentiometric curves did not show additional inflexion points typical for the cases which occurs fouling and scaling for the pH values evaluated, which is in accordance with the speciation diagrams of the solutions constructed with the aid of Hydra-Medusa software. Hence, the pH and the proportion of cupric ions did not show influence on the curves behavior.

Mar 1, 2018

By Timothy W. Ellis, John A. Howes

The production of lead-acid batteries is defined by a closed-loop product life-cycle. Active material and grid alloys converge on an adaptable specification that improves both performance and recyclability. This mapping of product requirements for lead-acid batteries has taken over 80 years to develop. But, as the use of batteries made with other chemistries continues to grow, the need for a comparable life-cycle management process becomes increasingly apparent given societal needs to manage raw materials, e.g. the European Union Battery Directive recycling targets. What has taken more than 80 years for lead-acid to evolve in a closed-loop paradigm must now be accomplished in less time for batteries using other chemistries and technologies. End-of-life costs are embedded in the product cost of lead-acid batteries. However, end-of-life costs are not reflected in the product cost of batteries made with other chemistries. Those costs are borne by other constituencies with often inefficient and environmentally damaging results. Lead-acid is a materials technology management model for other products.

Mar 1, 2017

By V. Reiter, K. Reinharter, C. Wenzl, D. Gregurek, A. Spanring

The refractory linings in lead furnaces are exposed to several stresses rather complex in their interaction. In the present study the magnesia-chromite brick out of a lead recycling furnace suffered from a high chemical attack by the process slag. The high CaO, BaO and sulfur bearing silicate slag, as well as a high NaO2 supply from soda resulted both in a deep-reaching infiltration of the brick microstructure and a severe corrosion of the brick components. Both the sintered magnesia and chromite were attacked chemically. The FactSage calculations showed the formation of high amounts of liquid phase in the infiltrated microstructure. Further phenomena affecting the refractory performance such as iron oxide attack, redox effects, and boron attack are also discussed in the paper. The obtained information and insights serve as a basis for improving refractory materials (i.e., choice of refractories for individual process and new developments) and consequently furnace operations.

Mar 1, 2017

By Lixin Qian, Tiejun Chun, Yifan Wang, Huan Wang, Hongming Long, Zhengwei Yu

To solve the problem that the sintered liquid phase fluidity characteristic of low silica (w(SiO2) < 3 wt%) and high silica (w(SiO2) > 7 wt%)) iron ores were different from actual sintering production with using the common method based on w(CaO)/w(SiO2), a new improved method based on n(Fe2O3)/n(CaO) was proposed. The differences between two methods for iron ore fluidity detection were studied. The results show that when the common method is used to detect the liquid phase fluidity, as the content of SiO2 increased from 2.12 to 11.68 wt%, the amount of CaO addition augmented from 7.88 to 32.65 wt% and the corresponding fluidity index changed from 0 to 5.68. The fluidity index has a linearly positive correlation with the content of SiO2. The improved method could significantly reduce the effect of the change of CaO addition on the fluidity characteristic of iron ore which caused by the difference of SiO2.

Mar 1, 2018

By Henry Gómez Urquizo

El presente trabajo señala que la capacitación y entrenamiento en tecnologías de automatización y control a distancia, es una alternativa viable para las poblaciones de jóvenes y adultos que se encuentran alejadas de los centros de entrenamiento especializado a través de los laboratorios virtuales de acceso remoto, los cuales permiten la realización de experiencias de aprendizaje semejantes a las que se logran bajo la modalidad presencial. Esta modalidad denominada "telepresencia", utiliza los recursos e infraestructura de los laboratorios reales que se utilizan en la capacitación presencial y mediante las TIC lo ponen a disposición de los estudiantes de los lugares remotos.

Sep 14, 2009

By F. Arslan

Gold extraction from refractory ores is still a problem. Gold losses in the cyanidation process are mainly due to the presence of sulfides and carbonaceous materials. Oxidation of carbon and sulfide minerals by sodium hypochlorite is a possible method to render the ore amenable to cyanidation, and earlier work by the USBM indicates that electrochemical generation of hypochlorite is promising. Laboratory work was carried out on the oxidation of pyrite and carbon in an electrochemical cell with a sodium chloride electrolyte. The results of preliminary tests are discussed in relation to the mechanism of electrooxidation of refractory gold ores and the estimation of current efficiency.

Jan 1, 1991

By A. Pankewitz

The well-established on-line particle size analyzer OPUS manufactured by Sympatec GmbH, has been successfully implemented in several mining and industrial minerals project. OPUS monitors the particle size distribution in 31 fractions as well as the solid concentration in opaque and highly concentrated ore and mineral slurries on-line in real time e.g. behind mills or cyclones applying 31 ultrasonic frequencies for highest resolution. Ultrasonic extinction overcomes all limitations known from optical and mechanical systems like contamination, blockage and wear. OPUS measures slurries in their original state without any dilution, hence no extensive sampling procedure or sample conditioning is required thus no dilution errors occur. Due to the OPUS design and suitable algorithms entrained air bubbles do not affect the quality of analysis at all. The sensor covers particle size distributions from 0,01 to 3.000,00 µm and solid concentrations up to 70 % by volume and can be easily adapted to a number of production lines simultaneously. Jiangxi Copper?s Dexing Mine is one of the biggest copper mines in Asia and among the first users for OPUS on-line particle size and concentration analysis in mining industry. OPUS is connected to 2 process lines. Jiangxi Copper has implemented OPUS for into their central control system for the grinding & classifying circuit of one SAG mill and one ball mill. Analysis data and process control as well as optimization based on OPUS particle size and concentration measurements will be discussed Keywords: particle size analysis, ultrasonic extinction, concentration analysis, grinding control

Sep 1, 2012