The 3D reconstruction of rock joint surfaces is crucial for quantifying rock joints. Through the uniform discretization of 2D and 3D rock joints, it was determined that both the climbing angles along the shear direction and the projection lengths of the consecutive ascending/descending segments follow normal distributions. This statistical distribution of climbing angles and projection lengths provides

The constant mi in the Hoek-Brown (H-B) criterion is a fundamental parameter required for determining the compressive strength of rock. In this paper, drilling parameters provide a new basis for determining the constant mi. An analytical relationship between the drilling parameters and constant mi is established in consideration of the contact response between the drilling bit and the cut rock in the

Simulations of solid–liquid flow on industrial scales are feasible within the Euler-Euler / RANS approach. The reliability of this approach depends largely on the closure models applied to describe the unresolved phenomena at the particle scale, in particular the interfacial forces. In this work, a set of closure models reviewed previously for this kind of application (Shi and Rzehak, 2020) is further

The secondary copper sulphide mineral, chalcocite, is the second most important copper mineral and its flotation is significantly affected by the surface oxidation. There is scarcity of reports on sulphidisation of oxidised chalcocite and literature suggests that the conventional sulphidisation experiences difficulties in activating sulphides that are prone to oxidation. Thus the objective of this

In recent decades, the exponential increase in the cell volume of flotation cells has promoted significant advantages, such as those related to investment costs, footprints, and energy savings. In larger cells, the diameter/height ratios and froth transport distances increase. Thus, the use of froth crowders and internal launders becomes compulsory for maintaining froth transport distances while decreasing

Due to the complexity of the real engineering environment, the arrival measurement inevitably contains outliers and leads to serious location errors. In order to eliminate the influence of the outliers effectively, this paper proposes a novel robust AE/MS source localization method using optimized M-estimate consensus sample. First, a sample subset is selected from the entire arrival set to obtain

The use of geometallurgical modelling is becoming common in the design of a concentrator plant and during its operational phase. Predictive modelling aims to define optimized process parameters for the concentrator plant to accommodate the variability of the ore feed characteristics. The main objective of this study is to simulate the metallurgical response for distinct ore unit types and their blends

This paper describes the chlorination roasting-water leaching process for the volatilization separation of gold, zinc and simultaneous vanadium recovery from carbonaceous gold ore. Chlorination roasting was conducted on carbonaceous gold ore. The chlorination residue and volatile precipitates were examined for textural and chemical properties. The results, and the thermodynamic calculations performed

In the present study, a selective leaching process of zinc from a low-grade carbonate source is proposed by the use of a green lixiviant, namely glycine. Response surface methodology (RSM) coupled with central composite design (CCD), was applied to optimize the levels of glycine concentration, pH and temperature and to quantify the significance of the factors and the interactions among them. Under

Waste electrical and electric equipment entering our recycling system poses various challenges in different stages of the whole treatment chain. Losses of valuable metals in the crushing of electrical devices through dusts and fines have been identified as one such challenge. Crushing is nevertheless crucial in order to liberate metals from each other for efficient separation in the sequential mechanical

The objectives of this research are: (1) to study the process of formation of efflorescence salt crusts (ESC) on the surface of tailings dams, (2) to evaluate the possibility of recovering critical metals and raw materials, and (3) to study its effectiveness as a tailings (MT) decontaminant. To achieve these objectives, the evaporation process of 3 columns containing a mixture of MT and distilled water

In our previous study, the mineral evolution and porous kinetics during nitric acid pressure leaching of limonitic laterite has been investigated. In order to optimize the nitric acid leaching technology, this paper investigated the dissolution behavior and porous kinetics of limonitic laterite during nitric acid atmospheric leaching. The experimental results showed that Ni and Fe had consistent leaching

To enhance the leaching of chalcopyrite in sulfuric acid solution at atmospheric temperature, chloride (Cl−) and ammonium (NH4+) were employed in this paper. Action of these additives in chalcopyrite leaching was explored, with an emphasis on the synergistic catalytic effect of Cl− and NH4+. It was demonstrated that the single addition of Cl− and NH4+ could promote the chalcopyrite leaching process

The interpretation of core level Synchrotron photoemisison spectra (SPES) collected from a pristine fracture surface of monoclinic pyrrhotite (Fe7S8), as a function of photon energy, has identified the three distinct surface species. The Fe 2p photoemission spectra show the Fe in pyrrhotite is high spin FeII in octahedral co-ordination. Comparison of bulk and surface sensitive spectra did not identify

In this study, Macadamia-derived activated carbon was utilized for the remediation of selected heavy metals from wastewater samples. The selected heavy metals include Pb (II), Fe (III), Cd (II), and Zn (II). The activated carbon used in the study was modified with KMnO4 and HNO3 to increase the content of the oxygen-containing functional groups on the adsorbent surface. Both the unmodified activated

Pyrrhotite is an associated mineral that exists widely in sulfide ore. The presence of pyrrhotite will affect the recovery of platinum group minerals. Therefore, researchers have paid increasing attention to the flotation separation of pyrrhotite. Pyrrhotite superstructures owning different Fe/S ratios results in various crystal structures, corresponding to different physical, chemical and electronic

In the one-step bioleaching process of uranium by Aspergillus niger, the formation mechanism and uranium bioleaching model of bio-ore pellets were explored and proposed. The results showed that the formation of bio-ore pellets could be divided into three phases. In the adaptive-growth phase, a small number of ore particles were adsorbed by mycelia to form flake mycelia with a diameter of 1–2 mm. In

An elastoplastic damage constitutive model is constructed in this work to describe the macroscopic mechanical behaviors of geomaterials with a “porous matrix - inclusion” microstructure. In order to consider the influences of microstructure on its nonlinear behavior, such as the porosity, volume fraction of inclusions and the properties of the solid phase, the macroscopic yield criterion derived in

Filled inclusions in rock discontinuities play a key role in the mechanical characteristics of the rock and thereby influence the stability of rock engineering. In this study, a series of impact tests were performed using a split Hopkinson pressure bar system with high-speed photography to investigate the effect of interlayer strength on the wave propagation and fracturing process in composite rock-mortar

Abstract not available

The utilization of Ca ion as assistant depressant of CMC on talc has been widely reported. Thus, the study on the adsorption mechanism of Ca ion on talc surface is very crucial for understanding the performance of CMC on talc depression. In this paper, mechanism insights into hydrated Ca ion adsorption on talc (0 0 1) basal surface were creatively provided using DFT calculation. [Ca(H2O)6]2+ and [Ca(OH)(H2O)3]+

In developing a geometallurgical characterisation for comminution, the geological information, usually captured from drill core with a resolution of down to micrometre scale, is compared with the results of comminution tests. These tests require several kilograms of material and are empirical tests that do not focus on understanding the effect of ore characteristics separately from the machine functioning

E-waste is considered to be one of the fastest growing solid waste streams in the world. India, the second most populous country in the world, generated more than 3.23 million tonnes of e-waste in 2019 and thus, has become the world’s third largest e-waste generating country. However, the documented formal e-waste recycling percentage in India is very low (less than 10%). The existing formal recyclers

Carbonaceous refractory gold ore has been an important gold ore resource for the sustainable development of the gold industry. Solving the harmful effects of mineral-locking is the first step to increase the gold leaching rate. This study employed vacuum roasting technology in the pretreatment of carbonaceous gold ore. The dissociation efficiency and mechanism of gold in carbonaceous gold ore was investigated

The inevitable presence of metal ions in the slurry significantly impacts the adsorption of organic depressants. In this study, the influence of Fe3+ and Ca2+ on the depression of chalcopyrite by carboxymethyl cellulose (CMC) was investigated. CMC slightly depressed chalcopyrite flotation, and the addition of Ca2+ hardly impact its depression effect. However, the pre-treatment with Fe3+ enhanced its

Most rocks exhibit time-dependent deformation and failure. Two main mechanisms are generally considered, the progressive growth of cracks and viscoelastic and/or viscoplastic deformation. In this study, cracking process is described by a viscous phase-field method which is coupled with a viscoplastic model. The evolution of crack field is controlled by both elastic and viscoplastic tensile volumetric

It has become an inevitable trend of human development to seek resources from the deep underground. However, rock encountered in deep underground engineering is usually in an anisotropic stress state (σ1 > σ₂>σ3) due to the influences of geological structures and engineering disturbances. It is therefore essential to study the mechanical, seepage, and dynamic disaster behaviors of deep rock under true

Gold concentration usually consists of gravity separation and froth flotation. However, flotation faces difficulties due to gold-bearing ores often being refractory and finely disseminated in nature. Poor recovery and low flotation kinetics of fine particles are mainly due to the low frequencies of particle-bubble collisions and an increase in entrainment of fine gangue particles decreases the grade

Removal of pre-adsorbed xanthate is a crucial step to the further separation of chalcopyrite from other sulfide minerals possessing similar floatability. Traditionally, adding excess sodium sulfide (Na2S) suffers from a series of environmental problems. Herein, to seek more effective alternatives, inorganic oxidizers i.e., KMnO4, H2O2 and Ca(ClO)2 were employed. Comparative effects of inorganic oxidizers

Steeply inclined settlers (SIS) are solid–liquid separators that feature close, inclined confining elements that allow significant settling enhancement when compared to vertical tanks, resulting in relatively low footprints at equal throughput. The present article reviews the working principle, flow configuration, capacity, and several technological advances related to this kind of equipment. The consistency

Selective separation of chalcopyrite from sphalerite is a challenge in mineral processing. This study is the first to use the organic compounds in fenugreek gum (FG) as a depressant for sphalerite to aid this separation. The results showed that FG exerts a selectively inhibiting effect on sphalerite in chalcopyrite flotation and thus is a potential sphalerite depressant. The underlying mechanisms were

Exposing the froth phase of a flotation system to low-frequency acoustic sound was reported to improve the process efficiency, which was thought to be due to the improvement in the froth stability. However, no direct evidence of the stabilization effect of sound on froths or foams is available to date. The present work aims to resolve this issue by experimentally studying the effect of low-frequency

A series of cyclic compression tests of marble spheres and scanning electron microscopy (SEM) imaging measurements were performed in this work. The cyclic compression tests of marble spheres reveal three different fracture types: Hertzian cracks, oblique fractures and multi-meridian fractures. The displacement of marble spheres with Hertzian cracks or oblique fractures in cyclic compression tests can

Recently a new grout material called WIS was invented for sealing water inflow in tunneling and underground constructions. In this study, a special experimental method called Intubated Counter Grouting (ICG) was proposed to investigate the influence of water dispersion on the rheological properties of the grout during the grouting process, and to testify the sealing performance of the grout, such as

The scaling laws describing the spatial arrangement of fractures along six deep boreholes penetrating the crystalline rocks in the Rhine Graben were derived using a correlation analysis. Five of the wells, two to 5 km depth, were located at the Soultz geothermal site and one well to 5 km depth was located at Basel, some 150 km from Soultz. Five datasets were derived from borehole imaging logs, whilst

The deep coal reservoir is in a high in-situ stress regime, and the drop in pore pressure during the coalbed methane extraction can induce significant slippage effect and effective stress change. Both of them play a competitive role in permeability evolution. In our research, coal seepage experiments under variable bulk stress and pore pressure paths are performed to investigate the slippage effect

The mining industry generates thousands of tons of waste every day. Some types of waste pose environmental risks, while others can be considered important sources of valuable materials. Nowadays, the re-processing of mine tailings starts to be seen as an increasingly more critical operation because of the need to shift from the current linear economy model to the circular one. However, full-scale mine

Understanding the stress distribution, deformation and fracture behavior around a circular hole or inclusion is critical for the stability assessment of rock structures such as tunnels and backfilled openings. In this study, the analytical solutions of stress and displacement distribution around a circular inclusion of different elastic properties were first derived based on the theory of elasticity