Carbon is a common gangue, often associated with base metal ores. The hydrophobicity of carbon causes interaction with air-bubbles during flotation, and results in carbon contamination of concentrate and grade reduction of base metals. Therefore, selective separation of carbon is important during froth flotation processing. Native and modified starch have been recommended to depress carbon during flotation

In this work we use the peridynamics theory of solid mechanics to simulate fracture in an annular rock domain subject to an in-situ stress and create surrogate models that predict the area of the resulting cracks. Peridynamics is a non-local formulation of continuum mechanics that naturally accommodates material discontinuities. Furthermore, unlike other fracture modeling techniques there is no need

An extensive field test was conducted by Rio Tinto and Eriez to evaluate the operability and metallurgical performance of a StackCell? SC-50 high-intensity flotation machine for recovery of copper and molybdenum from flotation tailings. The field test of the 15-m3 StackCell flotation cell was conducted at Rio Tinto’s state-of-the-art tailings recovery demonstration plant located within Kennecott Utah

The iron tailings of Bayan Obo mines are solid waste, which occupies land area and also causes environmental pollution; however, this waste can be recycled. In this study, based on the characteristics of iron minerals and fluorocarbonate contained in Bayan Obo iron tailings, clean magnetization roasting of iron minerals by bastnaesite from iron tailings during in-situ suspension magnetization roasting

A blasting experiment was conducted on iron ore samples by considering multiple coupling charge coefficients. The resulting internal fracture and damage characteristics were quantitatively analyzed via computerized tomography (CT), scanning, and three-dimensional (3D) model reconstruction. The results show that the iron ore primarily displayed radial and circumferential cracks along the blast hole

Enrichment of medium–low grade phosphate ore is very important for phosphorus chemical industry. This paper proposes a new enrichment method of medium–low grade phosphate ore with high silicon content via nitric acid leaching, separation and re-precipitation in sequence. The nitric acid leaching and the precipitation of the leaching solution were investigated and the P2O5 recovery reached 99.82%. The

The flotation separation of fluorite and calcite poses a long-standing challenge in the mineral processing industry because of their similar physicochemical characteristics. In this study, the effects of Cu2+ and soluble starch (SS) in the separation of fluorite from calcite by flotation, and the mechanisms behind these effects, were investigated using micro-flotation experiments, X-ray photoelectron

This study reports on the mixed-mode behavior of desiccation cracks in a clayey rock front gallery. As most digital image correlation (DIC) algorithms have access to the full-field measurements of the displacements and strains, the improvements in DIC now allow the automatic detection of the jumps in the displacements induced by the opening and sliding of desiccation cracks without imposed initial

This study systematically investigates the effect of deviatoric loading paths on diffuse and localized deformation developing during the mechanical loading of a high porosity (20%) Vosges sandstone (Eastern France). Laboratory scale experiments are performed using a high pressure true triaxial apparatus, designed to provide access to full-field surface kinematics at high spatial and temporal resolutions

The stability of the froth is known to strongly affect flotation performance. Literature shows that both frothers and ions reduce bubble coalescence, and stabilise the bubbles that form, resulting in greater froth stability. Considering both variables act on the froth in a similar manner, it is becoming increasingly important to understand how frothers behave under conditions of increased ionic strength

To investigate the anisotropy of coal swelling, this study proposes an effective stress model for saturated, adsorptive fractured porous media by considering gas adsorption induced surface stress change on solid-fluid interface. The effective stress model can be used to capture the anisotropic swelling of coal combining anisotropic mechanical properties and to link with the anisotropic permeability

The shearing characteristics of rock joints govern the mechanical performance of discontinuous rock masses. The present study investigated the normal compression and shear behavior of rock joints through cyclic compression tests and direct shear tests. The irreversible relationship between the normal stress and the normal closure was confirmed by cyclic compression tests on rock joints. An elastoplastic

Mechanical response with a snapback (class-II behavior) is one of the basic features of brittle rocks. This technical Note presents analytical studies on the critical condition which separates the class-I and class-II rock behaviors. Formulations under conventional triaxial compression are performed by making direct use of the closed-form solutions of the damage-friction coupling constitutive equations

Ground surface uplift was detected during longwall mining in the Lazy Mine, a hard coal mine in the Czech part of the Upper Silesian Coal Basin, Czech Republic. The greatest uplift was 218?mm, based on surface point levelling by comparing surface points with heights of non-mined areas. This uplift occurred during subcritical mining at an average depth of 740?m below the surface. The mined coal seam

Flotation is a kinetic process designed to separate mineral fines by control of hydrophobicity. In general, both the recovery and selectivity of a flotation process increase with contact angle. It is difficult, however, to model flotation kinetics using the thermodynamic parameter. In the present work, we consider flotation as heterocoagulation so that the bubble-particle interactions occurring in

Waste printed circuit boards represent one of the most challenging parts of e-waste recycling. The extraction of precious metals (gold, silver, palladium and platinum) from waste printed circuit boards has commonly been done using highly toxic, corrosive, or expensive lixiviants, such as sodium cyanide, aqua regia and iodine/iodide. The present study provides a greener approach to extract precious

The inevitable presence of zinc ions will increase the difficulty of removing quartz from zinc oxide ores using sodium oleate (NaOl) as a collector. The problem of separating smithsonite from zinc ions activated quartz (Zn-Quartz) is still unresolved. In this study, a readily biodegradable and environmentally friendly reagent (tetrasodium iminodisuccinate, IDS) was introduced for efficiently separating

Complex microstructures of pyrite induced by superimposed deformation and fluid infiltration in lode gold deposits can record time-integrated physicochemical changes of ore-forming fluids. This study used a combination of techniques (EBSD, μ-XRF, EMPA, APT, and TEM) to characterize and decode the microstructures of pyrite in an optically homogeneous polymetallic sulfide veinlet of the Wulong lode gold

In order to make the slag from desulphurization and slag skimming (SDSS) to be comprehensively recycled and utilized, a combined process of beneficiation and building materials preparation was proposed to recover iron from SDSS, meanwhile to apply the remaining slag tailings as cement admixture. From this process, three iron-rich products were recovered in stages by clean gravity - magnetic separation

The Paleocene coals of the Salt Range in the Punjab Province of Pakistan have great economic potential; however, their trace element and stable isotopic characteristics have not been studied in detail except for a few sporadic samples. In this study, a total of 59 coal samples of which 14 are obtained from open cast mines have been investigated for elemental composition and δ13C-δ15N isotopic signatures

To investigate the static mechanical properties and failure characteristics of damaged rocks after impact under realistic in-situ stress, dynamic triaxial compression tests with different strain rates and confining pressures were conducted on diorite by a modified split Hopkinson pressure bar. The damage factor was calculated according to the change of the longitudinal wave velocity of rocks before

The development of new flotation equipment has to address the challenges confronting the minerals industry, the low flotation efficiency of fine and coarse particles and the need to process a higher volume of ores due to the decreased feed grades. By combining a downcomer, a fluidised bed and inclined channels within one equipment, the Reflux Flotation Cell (RFC) offers a general solution to improving

In this study, a selective process for separation of vanadium and iron from the steelmaking slag was proposed. The proposed process has a potential to be considered industrially due to its relative simplicity. The process for the separation of vanadium and iron is consisted of three main stages: leaching, cementation, and solvent extraction. The leaching and cementation stage, were designed such that

This study reveals the important role of hydromechanical responses of large hydraulic fractures in the cause and mechanisms of induced seismicity associated with the Mw 5.5 earthquake at the Pohang geothermal site, South Korea. Fractures intersecting two stimulation wells, PX-1 and PX-2, were identified through a comprehensive analysis of various data produced from drilling and hydraulic stimulations

The salts contained in water can gradually accumulate in pore networks of rocks under wetting-drying cycles, which could cause rock deterioration. The salt-induced damage under this cyclic process can result in dynamically evolving mechanical and hydraulic properties of the rock, which is relevant to many rock-related engineering activities and geological hazards. In this study, the structure damage

Down-the-bank grade-recovery data are examined to determine whether the best performance could be correlated with balanced cell-by-cell recovery or balanced cell mass pull. Previous work had shown evidence in support of the former but here we show correlation with balanced mass pull may often be found. Balanced recovery seeks to maximize selectivity against a second floatable mineral while balanced

The genesis (primary versus secondary) of Mn carbonate-rich sediments, which consist of sub-economic rocks and ore deposits, remains hotly debated. Here, we investigated the petrographic, geochemical, and C–Mo isotopic characteristics of the Zhaosu Mn carbonate deposit in northwestern China, in order to provide constraints on its origin. The Mn ores occur within a Carboniferous marine transgressive

The recovery of fine mineral particles in flotation is limited owing to the low collision probability between the particles and air bubbles. The carrier flotation method can enhance fine particle recovery by attaching fines to coarse carrier particles. In this study, an attempt was made to improve the recovery of chalcopyrite fines using coarse pyrite particles as a carrier. Flotation experiments for

The world is facing critical technological and environmental challenges in the production of basic materials in high demand, such as aluminium and silica, whose processes were developed long ago. New production routes, involving using alternative resources and innovative technological solutions, are needed to secure access to these base materials at a lower cost to the environment, in terms of waste

The nature of the hydrothermal reaction between sphalerite (ZnS) and pyrite (FeS2) particles and copper sulfate (CuSO4) solution was investigated in this study. The effects of temperature (443–523?K), CuSO4 (0.08–0.96?mol/L) and H2SO4 (0.05–0.6?mol/L) concentrations, reaction time (1–120?min), stirring speed (40–100?rpm) and particle size (10–100?μm) on the conversion of sphalerite and pyrite were

Chlorite, as the most representative gangue mineral associated with specularite, of which the separation of these two minerals is difficult. This paper investigated the depression effect of taurine on specularite/chlorite separation via flotation experiments, adsorption tests, contact angle measurements, Zeta potential detection, FT-IR measurements, and XPS analyses. The results of single mineral flotation

To investigate frictional properties of the rupture surface of the carbonate Jiweishan rock avalanche, we conducted high-velocity-friction tests on the limestone and shale samples at different shear rates. The samples showed shear- and rate-strengthening of friction at low shear rates, but transformed to shear- and rate-weakening of friction at large shear rates. The critical shear rate was deduced

Thiosulfate is an eco-friendly gold lixiviant that is promising to replace the highly toxic cyanide. Copper is a conventional catalyst in accelerating the rate of thiosulfate leaching of gold, but it causes high thiosulfate consumption and complex gold recovery process. Attempts on the replacement of copper by other transitional metals such as nickel, cobalt and iron have been made to address the two

In deep underground engineering, rock burst and other dynamic disasters are prone to occur due to stress concentration and energy accumulation in surrounding rock. The control of dynamic disasters requires bolts and cables with high strength, high elongation, and high energy-absorbing capacity. Therefore, a constant resistance energy-absorbing (CREA) material is developed. In this study, the dynamic

In this work, the stable layer structure of serpentine, which seriously restricts the extraction of magnesium, was broken down, and a nearly 94% leaching efficiency of Mg was obtained by adding 5% fluorite powder. Compared with the system without fluorite, the Mg leaching efficiency increased by 36.42%. This result was achieved because the complexation of fluorinion (F?) with Si in serpentine promoted

Numerical modelling is widely used to estimate seismic potential in mines. Several numerical methods, along with different interpretation techniques, allow estimating the seismic potential at different stages of a mine or tunnel construction. However, none of the existing methods considers the magnitude of seismic events as a distribution of values, rather all methods focus on obtaining a single value

The occurrence of strainbursts is of major concern in underground deep mining operations. Strainbursts are complex events characterized by a spontaneous strain-energy liberation at the boundaries of underground excavations, putting both the long-term safety of operations and exposing workers to risk. In this study, we reported a series of uniaxial compression tests by using a split Hopkinson pressure

Four kinds of ionic liquids (ILs) with different counterions were used as collectors to perform flotation tests for pure quartz and quartz-hematite mixed ore. Pure quartz flotation showed that all ILs had excellent collection performance, exceeding 95% of the quartz was floated below the concentration of 8*10?5mol*L?1. All ILs showed much better collecting capacity than DDA. Mixed ore tests without