Variables of hydrodynamics are equally important as those of surface chemistry in determining the efficiency of froth flotation processes. In a mechanical flotation cell, macro hydrodynamics is responsible for solids suspension and aggregates transport, and micro-turbulence plays an important role in the sub-processes of flotation, such as gas dispersion into small bubbles and bubble-particle collision

The development of organic depressants for sulfide mineral flotation has received widespread attention, and metal ions can enhance or weaken the depression effect of organic depressants. In this study, the flotation behavior of pectin-treated galena and chalcopyrite in the presence and absence of copper sulfate was investigated through micro-flotation tests. Results showed that pectin merely depressed

The ongoing depletion of gold and silver-containing ore deposits demands a shift towards the processing of more complex sources. Leaching of gold or silver from these sources, which are named refractory and are typically low-grade, can be complicated due to one or more of the following effects: (1) kinetic or thermodynamic impediments on cyanide diffusion or on the dissolution of minerals, (2) readsorption

Purification of concentrated manganese sulfate solution by solvent extraction is discussed in this paper. The use of bis(2-ethylhexyl) hydrogen phosphate (D2EHPA) and bis(2,4,4-trimethylpentyl)phosphinic acid (BTMPPA) was studied in removal of impurities from zinc electrowinning anode sludge leachates. Over 99 % of zinc and iron were removed by both extractants at around pH 3 in two mixer-settlers

The effect of detonator position on rock fragmentation was studied at the Kevitsa open pit mine. Five full-scale field tests were conducted where the blasts were divided into test and reference areas, and compared with each other. In the test areas, the detonators were placed at or near the middle point of the explosive column, and in the reference areas, corresponding to the conventional blasts used

Atmospheric acid leaching behaviour of scandium (Sc) in two different types of laterite nickel ore from Indonesia was investigated. Ore and leaching residue characterization was performed by XRD, FTIR, XPS, and SEM-EDX. Ore characterisation showed that the major minerals in limonitic laterite were goethite, magnetite, hematite, and saprolitic laterite mainly consisted of goethite, magnetite, lizardite

Red mud is a waste generated during the Bayer process in the production of alumina. Recovery of metallic components of the red mud has both environmental and economic benefits. In this study, the effect of carbothermal reduction on the physical and chemical separation of red mud components, namely Ti, REEs, Fe, and Al, were investigated. At first, the impact of carbothermal reduction on the efficiency

Recycling has become an important part of the lithium-ion battery (LIB) life cycle due to the growing demand for energy storage in applications like electric vehicles. Recycling spent LIBs provides a secondary source for strategically scarce metals, like lithium and cobalt, and reduces the environmental impact of toxic LIB waste. Citric acid has been proven to be an effective lixiviant that complexes

Modelling for flotation control purposes is the key stage of the implementation of model-based predicted controllers. In Part I of this paper, we introduced a dynamic model of the flotation process, suitable for control purposes, along with sensitivity analysis of the fitting parameters and simulations of important control variables. Our proposed model is the first of its kind as it includes key froth

Electrical Impedance Tomography (EIT) can be applied to monitor a variety of mineral and chemical processes including: velocity measurements in drilling cuttings and hydrocyclone operations. Hydraulic conveying systems rely upon the knowledge of slurry density to ensure efficient transportation of the solids. Typically, density measurements exploit the attenuation of gamma ray photons which poses complex

The Tiegelongnan porphyry-epithermal deposit (2089 Mt @ 0.53% Cu, 0.08 g/t Au) is host to a large variety of Cu-sulfide minerals, mainly chalcopyrite, bornite, covellite, digenite, enargite, and tennantite. We used LA-ICP-MS to investigate the trace element geochemistry of the Tiegelongnan Cu-sulfides, as well as pyrite, to understand the correlation between sulfides and trace elements, gold in particular

Caustic soda (NaOH) treatment has enhanced rare earth element (REE) extraction from monazite. This study examined the effectiveness of caustic soda for RE-phosphates with lower concentrations for extraction from coal overburden, an alternative feedstock derived from mining waste. Pourbaix (Eh-pH) diagrams were constructed for La, Ce, Nd, Eu, and Y-PO4-H2O systems to understand the thermodynamics of

The presence of geological faults is a significant contributing factor to coal burst in underground mining. In this study, a large-scale discontinuum model was established based on geological and geotechnical conditions in a mine site, where a longwall face passed through a major fault. Four model indicators were calculated during the longwall retreat: model seismic energy (energy released by the model

The precursory response rate with the relationship of the time-reversed Omori law can characterize the damage acceleration behavior in the approach to the local instability of rocks. In the present study, the precursory acoustic emission (AE) response rate obtained by the local spatial AE events is employed to forecast the time-of-instability of sandstone under biaxial and true triaxial compression

The separation process, particularly gravity and electrostatic separation, is very important in the recycling processing industry. Some characteristics of waste cable, as well as separation have a significant impact on the results and effects of aluminium recycling. At the same time, this process requires a significant amount of energy which significantly affects the overall recycling costs. This paper

It is widely accepted that the implementation of model-based predictive controllers (MPC) ensures optimal operation if an accurate model of the process is available. In the case of froth flotation, modelling for control purposes is a challenging task due to inherent process instabilities. Most models for control have only focused on the pulp phase rather than the froth phase, which is usually oversimplified

Empty region detection has wide-rang application in geotechnical engineering, such as resource exploration and tunnelling engineering. The traditional geophysical exploration methods require plenty preliminary investigations, which are also greatly affected by various parameters and limited by wave velocity difference. Therefore, this paper proposes a new method for empty region identification in the

A block impact model based on the elasto-viscoplastic macro element approach is developed for regular base prismatic blocks. This model upgrades a previously conceived model for spherical boulders introducing (i) a rotational degree of freedom; (ii) a moment-rotation relationship; (iii) a toppling mechanism. The model can improve rockfall simulations by considering block geometry and the exchange between

Water presence causes a dramatic reduction of sandstone strength. Under compressive stress conditions, the strength of a rock sample is controlled by frictional parameters and the fracture toughness of the material. Here, we report fracture toughness, frictional and uniaxial compression tests performed on five sandstones under dry and water-saturated conditions, that provide new insight into the mechanical

S-wave attenuation in porous media is affected by the presence and properties of saturating fluids. We measured the ultrasonic S-wave velocities of three types of tight rocks (siltstone, dolomite, and sandstone) under partial fluid saturation conditions using the pulse-transmission technique. The S-wave attenuation is estimated by the centroid frequency shift and spectral-ratio methods. The fluid-saturated

How to sustainably produce bauxite by effective reverse froth flotation of kaolinite at low temperature is an urgent problem to be solved in the field of mineral processing. In this work, a novel amino-based Gemini surfactant butadiyl-1, 4-bis (dimethyl dodecylammonium bromide) (BBDB) was prepared and first utilized as a novel collector for kaolinite flotation. Its flotation performance for kaolinite

The bubble-particle detachment interaction is critical to the flotation of coarse (composite) particles which has attracted significant research interest in recent years. It is principally controlled by the capillary forces arising from the deformation of the air–water interface that has been quantified employing the single-particle models. However, these single-particle models can be far away from

Unravelling the genesis of metamorphosed mineral deposits can be complicated due to difficulties in separating between primary features and features that formed during the metamorphic overprint. Such uncertainty exists for stratabound and dolomite- and skarn-hosted Zn-Pb-Ag sulfide deposits in 1.89 Ga rocks in the Bergslagen lithotectonic unit (BLU) of Sweden, where a metasomatic vs. regional metamorphic

Steeply dipping, vein and tabular orebodies are traditionally extracted with longitudinal retreat mining methods such as Eureka and Avoca in a bottom-up sequence with delayed backfill. To increase productivity, sill pillars in the orebody are used to separate mining zones thus allowing production to take place simultaneously in two or more zones. While such mining methods are productive, they may be

The deformation properties of rocks ultimately become anisotropic depending on the orientations of mineral particles and sedimentary structures. Characterization of deformation anisotropy is important for accurate understanding of the deformation characteristics of structures constructed inside rocks (e.g., rock foundation and tunnel). The simplest anisotropic elastic model is transversely isotropic

Salt caverns for storing renewably produced hydrogen underground pose a promising option to reduce CO2 emissions by improving the utilization of volatile renewable energy sources. Rock salt limits the infiltration of hydrogen into the storage cavern walls due to its favourable low permeability. However, pressure-driven percolation may create discrete pathways for the fluid and damage the cavern. Depicting

A macro-NPR (negative Poisson's ratio) bolt, also called a He bolt, is a composite structure that is composed of two types of steel that are adjusted by design. The mechanical characteristics of the macro-NPR bolt are high constant resistance, large deformation, energy absorption, and impact resistance. In this work, the concepts of a “climbing angle” and a stick-slip element were introduced to analyze

This paper presents a case study of the modelling of the natural oxidation of pyrite in a refractory gold ore stockpile at a mine on the island of Aniolam in Papua New Guinea to predict the gold recovery through direct cyanide leaching. The stockpile comprises low-grade material that was mined twenty years ago to access the orebody. The value of this low-grade resource could be increased if the processing

Rock damage induced by underground excavation would cause irreversible degradation in the hydro-mechanical performance of the engineering rock mass depending on the excavation method, in-situ stress, and change of ambient conditions. As exploitation of resources continues being operated at hostile depths of the Earth's lithosphere, adaptive excavation design thus becomes imperative for ensuring sustainable

This paper presents a hybrid ensemble classifier combined synthetic minority oversampling technique (SMOTE), random search (RS) hyper-parameters optimization algorithm and gradient boosting tree (GBT) to achieve efficient and accurate rock trace identification. A thirteen-dimensional database consisting of basic, vector, and discontinuity features is established from image samples. All data points

Uniaxial compressive strength (UCS) is the most used parameter to measure rock strength. However, restrictions in sampling large volume of material, the need of very large set of results and onsite characterisation of UCS non-destructively are requirements in many scientific and engineering investigations. The estimation of UCS from a single non-destructive or minimally invasive technique (NDT) may

Tin and tungsten are important metals for the industrializing society. Deciphering the origin and evolution of hydrothermal fluids responsible for their formation is critical to underpin genetic models of ore formation. Traditional approaches obtain isotopic information mainly from bulk analysis of both ore and gangue minerals, or less frequently from in situ analysis of gangue minerals, which either

Tailings management is challenging and important task especially for the plants that are considering to utilize them. Cemented paste backfill (CPB) can be counted as one of them where the opportunities regarding to economy improvement exist. Within the CPB application, dewatering of the product is of crucial importance where thickeners are mostly preferred. However, alternative solutions should also

Rock joints with different matching conditions are widely existing in nature. The safety of engineering structure is significantly affected by the peak shear strength of mismatched rock joints; however, the available criteria do not work well for evaluating the peak shear strength of mismatched rock joints. In this study, the mismatched rock-like joints are first simulated by imposing various lateral

Phosphorus is a vital component of fertilisers – and a growing global population relies on a stable supply of agricultural produce. Endeavours to recycle phosphates from sewage sludge ash (SSA) have so far been limited by lacking understanding of material associations and the actual phosphate compounds in SSA. Owed to the high amorphous content of ashes, unlike X-ray diffractometry (XRD), automated

The direct reuse of weathered tungsten-ore beneficiation wastewater (WTBW) in tungsten-flotation system seriously deteriorates the flotation index of tungsten because of its high content of suspended solids (SS). In the present study, an innovative technology using calcium chloride (CaCl2) to remove SS from WTBW was established based on the theory of electroneutralization and chemical precipitation

The strong alkalinity of red mud prevents its application as soil aggregates, adsorbing materials, fillers, and building materials. Direct acid leaching is an effective method for dealkalization of red mud. However, the formation of silica gel in the process causes significant processing difficulties. Herein, a dry digestion method was introduced to red mud for the selective recovery of Na with suppressed

A coupled THMC (thermal-hydrological-mechanical-chemical) model is developed and applied to explore the potential feasibility of using scCO2 (supercritical carbon dioxide) as a working fluid in geothermal reservoirs. This is achieved by examining the evolution of the kinetics of mineral precipitation-dissolution and its associated impact on the evolution of the rock permeability and porosity. The pH

Fracture initiation and propagation in fluid-saturated rocks are controlled by interaction between fluid flow and rock deformation. The description of hydromechanical coupling is essential for modeling the fracture process. In this paper, an improved hydromechanical model is proposed in the framework of the particle flow simulation method. This model provides a better description of hydraulic properties

Prediction of the tunnel boring machine (TBM) performance is critically important for project scheduling and cost estimation. Various models have been proposed to estimate the TBM performance. However, most of these models used the parameters of rock specimens acquired from the laboratory tests, which differed from the in-situ conditions. It is difficult to apply these models to the engineering practice

The increasing demand of manganese in the industries and various hindrances in its production from low grade ores by conventional method has made it imperative for researchers around the world to develop a method of manganese extraction from low grade ores that is both environment-friendly and economical. Bioleaching has shown significant potential in manganese extraction and efficiencies of extraction

Cement-based grouting has been widely used in mining engineering; its constitutive law has not been comprehensively studied. In this study, a novel constitutive law of cement-grouted coal specimens (CGCS) was developed using hybrid machine learning (ML) algorithms. Shear tests were performed on CGCS for the analysis of stress-strain curves and the preparation of the dataset. To maintain the interpretation

The long-term stability of the roof is particularly important in designing underground rock structures. To estimate the durability of roof strata in underground excavation, a computation scheme of subcritical crack growth is proposed in this study. By adopting the proposed method (1) the potential collapse location of strata is derivable in accordance with a static model, (2) the durability of roof

Fluid injection into a rock mass from industrial processes can cause perceivable seismic events that may raise public concern. This seismicity can be caused by injection-induced fluid pressure in the rock mass causing slip on faults. Here we provide a method to distinguish between aseismic and seismic mobilisation and to predict fault movement due to anthropogenic fluid injection. This was achieved