To adequately utilize the critical rare earth resource by flotation, finding effective collectors has attracted increasing attention in the mining industry. A promising collector group is dithiocarbamate ester surfactant. In this study, S-[(2-hydroxyamino)-2-oxoethyl]-N, N-dibutyl-dithiocarbamate (HABTC), S-[(2-hydroxyamino)-2-oxoethyl]-N, N-dipropyl-dithiocarbamate (HAPTC), and S-[(2-hydroxyamino)-2-oxoethyl]-N

With the increasing scarcity of Earth’s resources and the development of space science and technology, the exploration, development, and utilization of deep space-specific material resources (minerals, water ice, volatile compounds, etc.) are not only important to supplement the resources and reserves on Earth but also provide a material foundation for establishing extraterrestrial research bases.

Bubble size and froth velocity are the most important froth characteristics used for evaluating and controlling flotation systems. Bubble size is often measured using watershed and edge detection algorithms. These algorithms typically result in the over-segmentation of big bubbles or the under-segmentation of small ones. Froth velocity is usually determined by processing successive images using various

Wear due to compression and abrasion from particles is a critical issue for high pressure grinding rolls (HPGR) mills. Understanding the evolution of wear provides useful insight on its mechanisms and helps to mitigate the issue so mills are operated at their optimal states. This work presented numerical simulations based on the discrete element method (DEM) to analyse the formation and evolution of

Clear understanding of overburden failure propagation during underground mining is critical in managing safety and environmental issues such as rock burst hazards, groundwater inrush and longwall convergency. This paper presents an in-situ monitoring study of overburden strain dynamics at a kilometre-deep longwall mine using distributed fibre optic sensing technology (DFOS). A deep borehole was drilled

Driven by environmental concerns and restrictions arising from them, the mining industry has instituted an initiative to recycle process waters within plant operations. This has the two-fold advantage of using minimal freshwater for mining, thus freeing the water for other applications, and limiting the release of potentially toxic discharge to the environment. However, in recycling their process water

Hydroxyethylidene diphosphonic acid (HEDP) is an industrial environmental reagent, often used as a chemical raw material in industrial water treatment, household cleaning products and personal care products. In this work, the effort to use HEDP to the flotation of pyrite containing fine-grained serpentine was conducted, and the selective separation of serpentine and pyrite was accomplished. During

Indium (In) is a rare precious metal with extremely low abundance in the Earth's crust, mostly occurring as impurities in sphalerite, and it is closely related to the high iron content in sphalerite. Flotation is generally used to recover such minerals. However, there are few for the flotation mechanism of sphalerite containing indium and iron impurities. In this paper, the adsorption of xanthate (C4H9OCSS−)

The effect of blasting vibration on the macroscopic failure characteristics of underground tunnels has been investigated, but little attention has been paid to the stress and deformation characteristics of underground tunnels under the combined action of explosion waves and in-situ stresses. Consequently, enhancing the bearing capacity of surrounding rock masses by adopting effective reinforcement

Surface defects are prevalent in natural rock masses, and the newborn cracks that initiate from these defects and significantly affect structural stability usually extend in a three-dimensional (3D) manner. Hence, in this research, a series of uniaxial compression tests were conducted on sandstone specimens containing a surface flaw to examine the effect of nondimensional flaw depth (0, 0.3, 0.5 and

Analytical description of the process of rock discontinuity caused by the operation of an experimental cutting head, in which a combination of cutting and loosening methods was used, is presented. Loosening of the rock fragment takes place after reaching the tensile or shear strength of the rock, what is more favourable compared to the classical mining methods. An analytical model of the stress in

Strain rockburst poses a great threat to the construction safety of deep engineering, especially induced by dynamic impact loads such as blasting from the adjacent tunnel excavation. Aiming to clarify the failure characteristics and mechanism of strain rockburst induced by the dynamic impact load, a series of dynamic impact tests under different biaxial prestress conditions were conducted on the sandstone

Two critical factors, namely intense precipitation and intricate excavation, can trigger rock mass disasters in mining operations. In this study, an indoor rainfall system was developed to precisely regulate the flow and intensity of precipitation. A large-scale model experiment was conducted on a self-designed physical simulation experiment platform to investigate the failure and instability of high-steep

Fertilizers have been given significant attention due to their critical need for agriculture yield to meet the demand for food growth arising from population growth. The demand for potassium fertilizer (metric tons of K2O) has increased by 12% between 2015 and 2020. Therefore, the concern about the limited availability of soluble potassium resources in the southern hemisphere has become a key research

The reverse flotation of Itabirite iron ore is typically performed after a desliming step in which most of the sub-10 µm particles are removed. This is done to limit processing problems such as poor flotation recovery of SiO2 due to slime coatings, increased slurry viscosities, unmanageable froths and increased losses of hematite particles due to entrainment. However, the rejection of ultrafine particles

Tetraalkyldiglycolamides are known for their high extracting efficiency of rare earth elements (REEs) from nitric acid solutions (1–6 mol/L). Nevertheless, solid-phase extractants based on diglycolamides (DGA) are poorly studied for REEs extraction. This paper explores the design and synthesis of novel REEs adsorbents by grafting silica with diglycolic acid-based ligands. The newly developed solid-phase

Clay shales are low-permeable sedimentary rocks that exhibit inherent cross-anisotropic stiffness, strength, and permeability. Accurate design of tunnels excavated in clay shales requires appropriate constitutive models that account for the anisotropic properties of the host rock, especially under undrained conditions. This paper presents a transversely isotropic elastoplastic-damage model for fully-saturated

Heterogeneity is an inherent feature of subsurface rocks. Unconventional reservoir shales, a group of typically fined-grained sedimentary rocks, usually exhibit strong heterogeneities due to the diversity of their constituents, including stiff silicate and carbonate minerals, ductile clay minerals, and organic matter. Understanding the influence of heterogeneities on the mechanical response as well

Understanding the scale effect in the behavior of solid materials is important when small-scale models are used to predict the behavior of real structures. Tremendous efforts have been devoted to investigating the scale effect in the strength of quasi-brittle materials. However, limited studies have focused on the whether there is a scale effect in bursting failure, which is a typical failure pattern

This study investigates the propagation and attenuation characteristics of shock waves produced by drilling and blasting. The focus is on a novel method for calculating the attenuation of the shock wave pressure. Based on the propagation of shock waves in a rod with a variable section and a Maxwell model for rock, theoretical solutions for the attenuation of the blast-induced shock wave pressure were

This paper presents the results of an ultrasonic-assisted alkali-acid leaching process for concurrently recovering rare earth elements (REEs) and coal from South African run-of-mine (RMC) and discard (DC) coal. The response surface methodology (RSM) was used during the alkali leaching of DC to evaluate and optimise the process parameters. REE recovery increased while ash content decreased with increasing

Heterogenite is an important cobalt oxide mineral, however, few investigations on the surface properties and flotation recovery of heterogenite were conducted. In this study, the effect of sulfidization on the surface property and flotation behavior of heterogenite was studied for the first time, using X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy and energy dispersive X-ray

The thick and steeply inclined coal seams of the Junggar Basin of Xinjiang, China, are unique with dip angles generally >50° but over the range 0°–85°. Initial and evolving permeability and pressures change drastically around wells down-dip within the steeply inclined reservoir as a result of the depth differential. Hence, the evolution of permeability and fluid pressures during drainage exhibits significant

Acoustic emission (AE) technology is widely used to monitor the damage evolution of rock. Identifying AE signals is crucial to reveal the rock cracking mechanism. The current tension and shear signal discrimination methods primarily rely on AE parameters. However, the differences between AE parameters and waveform images used as inputs require further exploration. Acoustic emission data from Brazilian

We propose a novel method for studying the λ/μ ratio, the vP/vS ratio and Poisson's ratio of rocks based on the determination of highly accurate moment tensors of acoustic emissions (AEs). The validity of the method is verified on observations of 539 AEs recorded in a sandstone sample during a semi-circular bend test. We show that the sandstone exhibits the so-called bi-modular behaviour indicating

To reveal the size effect and lateral pressure effect of columnar jointed basalts (CJBs), the meso-damage mechanics, statistical strength theory, continuum mechanics and digital image correlation are combined, and a series of heterogeneous numerical models of CJBs orthogonal and parallel to column axis are established. The elastic modulus, Poisson's ratio, uniaxial compressive strength, friction angle

Borehole breakout is a natural phenomenon resulting from in-situ stress redistribution around a borehole, and its orientation and geometries are critical indicators for in-situ stress direction and magnitudes. The aim of the study is to better understand the borehole breakout formation mechanism and reproduce breakout geometries using numerical simulations. A 2D bonded-particle model (BPM) is developed

Sphalerite flotation is conducted under Cu2+ activation system, whereas the selective separation of pyrrhotite is difficult due to the inevitable activation effect of Cu2+, which requires a large amount of lime to depress pyrrhotite flotation. In this study, the conventional collector butyl xanthate and a novel collector ML8 were compared to the selectivity of the flotation separation of sphalerite

Various numerical methods have been developed for modelling rock fracturing problems. Most of the available studies could reproduce reasonable results for given experimental data, but the ability and accuracy of these methods to predict rock fracturing are still controversial, and a systematic comparison is lacking. In this study, a set of rock mechanics experiments were designed for a numerical modelling

Users of the digital image correlation method are faced with the problem of poor operability, low repeatability, and lack of standardized specifications for spraying speckles. To solve the problem, the research proposed a rock deformation measurement method that obviates the need to spray speckles. A local binary model was established by using the local binary pattern (LBP) operator based on deep texture

An important index to evaluate the process efficiency of coal preparation is the mineral liberation degree of pulverized coal, which is greatly influenced by the particle size and shape distribution acquired by image segmentation. However, the agglomeration effect of fine powders and the edge effect of granular images caused by scanning electron microscopy greatly affect the precision of particle image

The review covers the development and the state of the art in deep-sea mining rock mechanics, equipment and challenges. It begins by introducing the significance of deep-sea mining, the types and geographical distribution of deep-sea resources. Section 2 reviews the mechanical properties and fracture mechanism of seabed and related continental rocks, which contributes to the advancement of relevant

Cemented paste backfill (CPB) technology has the advantages of safety, environmental friendliness, economics, and efficiency. This method offers assurances for practical underground mining and tailings pond management. The bed drainage channel structure and coarse particles with diameters above 45 μm were reconstructed and quantitatively characterized in 3D by computed tomography (CT) for the whole

Rockburst in deep rock engineering poses serious threat to personnel safety and engineering. In order to reveal the rockburst characteristics in deep engineering, the rockburst investigations and rockburst mechanisms based on in-situ stress were carried out at five deep gold mines in Jiaodong Peninsula, China. At the cover depth between 400 m and 600 m, the ground pressure hazards are mainly local

Creep of shale controls the stability of fault gouge in sedimentary rocks, aseismic deformation in the upper crust, and several engineering operations, such as proppant embedment, reservoir subsidence, and wellbore stability during unconventional shale gas exploitation. However, measuring the creep properties of shale is challenging due to the multi-scale structure of this rock. Here, our goal is to

The caving mining method relies on gravity to transport large amounts of caved ore and rock, therefore, the gravity flow rules are the foundation for determining or optimizing the stope parameters. The stochastic medium draw theory of gravity flow is relatively fast and easy to implement, and it can describe different shapes of the drawbody. However, the theory usually regards the drawpoint as a point

This study focuses on rock damage potentially developing in the near-field of a planned underground nuclear waste repository at the Forsmark site (Sweden). In hard, crystalline rocks, mechanical damage in the form of spalling may be induced during construction by overstressing of the excavation periphery. During operation, thermal damage may develop due to additional thermo-elastic stresses forming

Grinding ores in conventional ball mills demands high energy consumption, resulting in relatively high operating costs in a typical mineral processing industrial plant. Whether in the initial stages of a mining project or during its operation, conducting tests to determine the processing circuit’s energy consumption throughout the life of mine is necessary in order to reduce such high operating costs

High voltage pulse discharge (HVPD) is a new type of crushing technology with good application. Existing studies have focused on the crushing characteristics, with less reports on follow-up work. This study magnetization roasts hematite ore after mechanical crushing and HVPD, analyzing the difference in the roasting effect between the two crushing methods by establishing a new system of HVPD-magnetization

To improve the flotation recovery of tungsten minerals, 4-alkoxy benzohydroxamic acids containing C3 alkyl (C3OBs), namely 4-propoxy benzohydroxamic acid (POB), 4-iso-propoxy benzohydroxamic acid (IPOB) and 4-allyloxy hydroxamic acid (AOB), were designed as scheelite and wolframite collectors. The micro-flotation results uncovered that C3OBs exhibited stronger collecting ability towards Pb(Ⅱ)-activated