Sc-CO fracturing would be a potential stimulation method for Hot Dry Rock. A series of Sc-CO fracturing experiments were performed on granite under different temperature and stress conditions. Quantitative and qualitative analysis of injection pressure curves and cracks were conducted to explain the Sc-CO fracturing mechanism under high temperature and high stress conditions. Under the same stress

In the geo-energy industry, fluid injection induces different slip behaviors of a rock fracture, from aseismic creep to dynamic slip. The transition from aseismic creep to dynamic slip is explained by the ratio of the stiffness of surrounding rock and the critical stiffness of the fracture. However, numerous studies suggest multiple controls affecting the slip behaviors, and their joint influences

The separation of galena (PbS) from chalcopyrite (CuFeS) requires strong oxidants for the depression of PbS, due to the excellent hydrophobicity of PbS. In this work, an advanced oxidation process, i.e., SO/Fe treatment, was employed to selectively depress PbS. The parameters of the SO/Fe process were determined via flotation tests as follows: pH 3, 1:1 SO: Fe molar ratio, and 10 min reaction time

Various novel assisted drilling technologies enhance rock fragmentation performance by introducing microcracks on the rock surface to weaken rock strength. However, the quantitative relationship between artificially induced microcracks and rock fragmentation characteristics is not clear. In this study, we induced artificial microcracks of varying degrees on the rock surface through one-dimensional

Stress change in rock mass caused by human activities has the potential to cause the sliding and destruction of faults and joints, resulting in induced seismicity. Laboratory experiments are conducted on a simulated fault with various teeth numbers and undulation angles to uncover the mechanism of stress change-induced seismicity. The potential risk of induced seismicity is explained using three methods:

Hyperspectral imaging (HSI), a promising technique integrating imaging and spectroscopy, can help sort iron ores with different total iron (TFe) contents. However, the adhesion of dust (caused by crushing) or water can affect the sorting process. Currently, the mechanisms underlying this influence and methods to conveniently mitigate it remain unclear, hindering the practical application of HSI-based

The current suite of algorithms used in intelligent mineral sorting equipment is largely generic, lacking the necessary adaptability and the capability for simultaneous non-destructive structural detection and quantitative analysis. To address this, we have developed two specialized algorithms based on X-ray absorption spectroscopy: the Trans-LSTM algorithm based on Transformer and Long Short-Term

Seismic monitoring routines provide a robust framework for assessing rock stability and dynamic hazards in underground mining operations. However, the labor-intensive task of manually identifying wave arrivals and the suboptimal selection of geophone arrays do not meet the stringent timeliness and accuracy necessary for seismic source location in such contexts. The precise identification of wave arrivals

Peridotites (olivine-rich rocks) naturally react with CO-rich fluids to eventually form carbonates. Complete conversion involves incorporation of substantial amounts of CO, which requires prolonged fluid flow. Yet, these reactions also cause a large increase in solid volume (63–84 %), raising questions on how they proceed in nature without this excess solid volume clogging fluid pathways. It has been

Copper mining produces immense amounts of tailings due to low ore grades. These residues are increasingly dewatered by filtration in recessed plate filter presses to ensure safer storage and high recovery of water. The process parameters filtration pressure, desaturation time, desaturation pressure and cake thickness have a significant influence on achieving water content as well as bulk material stability

In the minerals industry, froth flotation is a commonly used method for separating valuable minerals from gangue. The design and efficient operation of flotation cells require a knowledge of the interplay between the system hydrodynamics and its chemistry. These parameters however are often examined in isolation using bare bubbles due to the system complexity. This study aims at investigating the coupled

Due to the thin overlying formation of ultra-shallow buried large-span urban tunnels, the surrounding rock can be easily loosened and damaged after excavation. High prestressed anchoring support can improve the self-bearing capacity of the surrounding rock. However, traditional bolts often undergo necking fracture after the yield stage and strengthening stage, and the designed pre-tension is low, generally

The refractory metals tungsten, tantalum and niobium are considered critical raw materials in Europe. Diversifying the supply of such materials, for instance by recovering refractory metals from local low-grade ore materials could reduce their supply risks. However, the extraction processes require to be efficient with a low energy and material consumption and a minimal environmental impact. In this

The influence of mechanical activation (MA) and mechanochemical activation (MCA) with Fe and FeO on the microstructural changes, leachability and leaching rate of natural chalcopyrite was investigated and compared. MCA pretreatments were carried out by chalcopyrite co-milling with Fe and FeO for 20 and 50 min. The XRD analysis indicated that even after 50 min MA and MCA, constituent phases of chalcopyrite

Vanadium-bearing titanomagnetite (VTM) is a crucial source for vanadium production. Conventional methods for recovering vanadium from VTM involving combined pyro- and hydrometallurgy (production of vanadium-rich slag, followed by leaching) or direct leaching encounter significant challenges, such as vanadium losses and complexities in metal separation stage. This study proposes an innovative approach

In this study, three separate flotation systems were studied to define the residual collectors found in different recycled water for sulfide (xanthate-chalcopyrite), non-sulfide with anionic (NaOL-dolomite) and cationic (DTAB-quartz) collector processes. The adsorption/desorption of collectors and the adsorption morphology were studied by the zeta potential and atomic force microscopy (AFM) measurements

In ores containing rutile, chlorite is the most common silicate gangue mineral. However, the flotation separation of rutile and chlorite has yet to be thoroughly studied. In this study, carboxymethyl cellulose (CMC) was used to depress chlorite when sodium oleate (NaOL) was used as the collector of rutile. The selective depression and its mechanism were investigated through micro-flotation experiments

Iron grain growth during deep reduction roasting is important for iron enrichment from copper slag (CS) through magnetic separation. In this work, a novel method of additive-free activation roasting, including oxidation and subsequent reduction roasting, was proposed to increase the iron grain size, then the iron was extracted by magnetic separation. The phase transformation of CS during activation

Global mineral demand is forecast to increase significantly to achieve the transition to renewable energy. Greater volumes of ore of lower grade will have to be mined to meet demand. Techniques to process large volumes of low-grade ore efficiently are being investigated to reduce the cost and impact of mining. One technique is to use sensor information to sort mined material, allowing waste to be discarded

Tracking mill liner wear is essential for improved plant reliability and grinding performance. This study developed a novel IoT wear sensor and a Discrete Element Modelling coupled methodology to predict and continuously evolve shell liner’s wear pattern. The IoT sensor was purposely developed to track and report the live thickness of a shell liner. Global wear pattern was then obtained by coupling

Copper (Cu) extraction from low-grade ores is limited by the formation of secondary minerals that can passivate the surfaces of Cu-sulphide minerals in these ores. Hence, a novel approach utilizing AlCl as a lixiviant was developed to modify coupled dissolution-reprecipitation processes at the mineral interface. The formation of Al-rich phases instead of Fe-hydroxysulphates enhanced Cu extraction through

Seismic events associated with longwall coal mining have not been comprehensively understood, in particular the spatial-temporal relationship between mining-induced seismic events. Current studies on longwall mining-induced seismicity have proposed various spatial-temporal relationships between seismic events, but they may not explicitly follow the Gutenberg–Richter (GR) law for seismic magnitude distribution

Rock discontinuities significantly impact the mechanical and hydraulic behavior of rock masses. A crucial aspect of rock engineering involves classifying discontinuities with similar orientations into groups. For this purpose, clustering algorithms, such as K-Means and Fuzzy K-Means (FKM), have been employed. However, the outcomes of these algorithms are influenced by the selection of initial cluster

“Peak carbon dioxide emissions、Carbon neutrality” is the two stage goal of carbon emission reduction proposed by China. Carbon emission accounting is the basic premise for effectively carrying out various carbon emission reduction work and promoting the green transformation of the economy. The coal industry is one of the key objects of carbon emission reduction. Taking Zhenneng Coal Preparation Plant

The beneficiation and recovery of ores with complex nature, low abundance have become the main direction for the development of niobium resources. The niobium resources with large reserves in Bayan Obo have not been effectively developed due to their fine particles, low grade, and complex nature. A new method for the phase reconstruction of minerals through a reconstruction process was proposed. The

Concentration of spodumene from lithium pegmatite ore generates large amounts of tailings that need to be recycled for sustainability and circular economy concerns. This study investigated the preparation of high-alumina porcelain compositions incorporating spodumene tailings, i.e., quartz feldspar silt (QFS). The mix design closely matched the theoretical composition of 60.51-wt.% AlO, 34.34-wt.%

Deep underground excavations in brittle rocks are subject to several ground stability hazards such as spalling and rockburst. These hazards are typically associated with brittle failure mechanisms for hard and massive rock mass. In this study, an experimental investigation has been carried out to evaluate the mechanisms underlying these induced hazards in deep underground excavations. The main objective

The microstructure of rock salt significantly influences its macroscopic mechanical behaviors and deformation phenomena. Understanding the deformation and failure characteristics of rock salt at multiple scales is crucial for the secure and efficient functioning of energy storage in salt caverns. Although the macroscopic behaviors of rock salt are well understood, the microstructural changes occurring

The original “hybrid bolt” was a pragmatic solution to address installation issues in the use of resin grouted rockbolts in heavily fractured ground and the inadequate capacity of friction rock stabilisers. The original hybrid rockbolt involved installing a resin rebar in a friction rock stabiliser. The development of Yielding Mechanical Hybrid Rockbolts has been driven by efforts to eliminate the

Deep-hole blasting, characterized by large diameter and long charge length, is a prevalent practice in large-scale underground mining. However, the increasing charge length in each borehole, together with the growing charge weight, necessitates a heightened focus on the induced vibration effects. Understanding the impact of long charge length on induced vibration in comparison with traditional vibration

Bauxite residue (BR) is major by-product of the Bayer process for aluminium production, and its accumulation confers environmental risk due to its high alkalinity and fineness. The high Fe content and the BR abundance render it an attractive secondary source of iron, with magnetic separation being the preferable beneficiation technique applied for quality upgrade.

Weak interlayers (WI) are common in sedimentary rock masses in deep coal mines. The qualitative effect of the WI on rockbursts is widely acknowledged; however, its influence mechanism still needs further investigation. In the present study, true triaxial unloading rockburst tests of sandstone with WI and calcite veins (CV) were conducted to explore their influence mechanisms. To explore the impact

Tensile strength is one of the most critical design factors in many rock engineering projects. However, despite many available testing techniques, an accurate estimation of the true tensile strength of quasi-brittle rock-like materials is yet a controversial problem since it can vary by the shape and size of a test specimen, the adopted test method, and applied loading conditions. Different studies

The study addresses the management of electric arc furnace dust (EAFD) generated by steel manufacturers and the challenge of metal leaching from this waste. Recognizing the scarcity of rare earth elements (REEs) and the industrial importance of manganese, the study emphasizes the urgent need for their recovery from waste. The current study presents a green approach using a biolixiviant from IBRC-M30168

Erosion is one of the continuous wear mechanisms in cohesive materials caused by the shear stress applied by the fluid flow at the liquid–solid interface. The erosion resistance of cohesive materials is significantly influenced by the strength of the cohesive bonds that hold the particles together, increasing the complexity of the mechanism. The erosion rate of cohesive materials depends on the critical

Owing to the technological limitations associated with beneficiation technology, large amounts of flotation reagents remain in mineral processing wastewater, which is extremely detrimental to humans and the environment. In addition, direct reuse of mineral processing wastewater will adversely affect the entire mine water system. Efficient treatment of residual butyl xanthate from tailing wastewater

In the field of tunnelling applications, it is often found that the rock masses exhibit anisotropy and rheological properties. To optimize the utilization of underground space, the use of noncircular tunnels is often preferred. However, it is important to note that these noncircular tunnels can lead to high-stress concentrations and significant displacements.

Growing demand for high-purity AlO for the electronic market and green energy production, allied with the need to decrease waste generation and dam use, will impact the future of mining, and new processes should be developed. The present study aimed to develop a hydrometallurgical process to obtain high-purity AlO from bauxite. Among the samples studied, BX03 had the highest AlO (63.8 %) and lowest

There is evidence of a very weak interaction between sperrylite and xanthate collectors at pH 9, the typical pH used in PGM concentrators. This results in the mineral being hardly hydrophobic when exposed to such collectors. Xanthate collectors adsorb via an electrochemical mechanism which is dependent on pH and Eh. In this study, it was shown that potassium amyl xanthate (PAX) adsorption increases

In the leaching of copper sulfide ores or refractory gold ores in chloride solutions, the regeneration of oxidative agents such as Cu (II) and Fe (III) is a key aspect for a sustainable process over time. This regeneration is carried out from the oxidation of Cu (I) and Fe (II) with O, which helps to maintain a conveniently high oxidative potential in solution and a high leaching efficiency. In this

The disturbance wave caused by excavation or blasting of underground surrounding rock causes fatigue degradation effect of rock and eventually leads to disasters. However, the fatigue damage characteristics and fatigue models of rock under true triaxial disturbance are scare. Therefore, a series of true triaxial disturbance tests were conducted to investigate the rock fatigue deformation, strength

Recognizing and quantifying the elasto-plastic nature of underground formations is critical for various subsurface operations such as drilling, stimulation, production, injection, and storage. In the case of geological CO2 storage, for instance, it is key to identify storage sites characteristics and pumping parameters that lead to safe and perennial CO2 trapping. In this work, we investigate different

Deep mine rock mass is in high static stress and dynamic disturbance coupling conditions, its mechanical properties and failure mode is different from the shallow rock mass, which leads to low rock blasting efficiency and engineering geology hazards. In-depth research on the dynamic response of rock blasting under in-situ stress will help to optimize the blasting design, improve the blasting efficiency

The flotation effect of the association formed by dodecyl trimethyl ammonium bromide (DTAB) and dodecyl alcohol polyoxyethylene ether sodium sulfate (AES), and nonpolar kerosene mixed collectors on low-rank coal (LRC) was investigated. The results show that the combustible matter recovery was significantly improved compared with a single kerosene from 49.88% to 74.97% when the the mixed collector was

Bacterially assisted leaching has been proposed for many innovative applications, such as urban mining or micromachining, but many technical challenges including substrate toxicity and downstream processing of the leach liquor must be solved before its industrial implementation. This study was conducted with the final goal of improving the average specific metal removal rate (SMRR) and reducing the

The presence of silicate minerals is a common occurrence in various ore types, including nickel sulphide ores. These silicate minerals dilute the grade of flotation concentrates through recovery by entrainment which leads to poor flotation performance and subsequently loss of values. Flotation by entrainment is further enhanced as the particle size of the feed becomes finer. The present work investigates

This paper describes the development and validation of a submersible sensing technology for industrial flotation cells. The sensor provides simultaneous real-time measurements of gas and solid holdups, as well as the density and viscosity of the slurry in the pulp zone of flotation machines. The submersible device comprises a gas exclusion cell, which resembles an inverted truncated cone assembled

During deep shale gas production, flowing water-based working fluid inevitably cools shale reservoirs around boreholes and some fractures, and possible extraction methods induce dynamic stresses. To understand the dynamic tensile behavior of deep anisotropic shale reservoir after water-based working fluid cooling, a split Hopkinson pressure bar was used for performing the dynamic Brazilian tests on

Baerzhe ore deposit is rich in such critical elements as rare earth elements (REEs), niobium (Nb), and titanium (Ti). However, in this ore, the REEs/Nb/Ti-bearing minerals are interlocked closely and thus not easily liberated and separated from each other by mineral processing methods. In order to achieve high recoveries of these critical elements, a concentrate mixture of REEs/Nb/Ti minerals can be

Overhaul slag is a hazardous waste which is from the process of aluminum electrolysis industry. In this work, a technology of calcium sulfate roasting and water leaching was developed to dispose of overhaul slag. The effects of roasting and leaching parameters were investigated in detail. Under the optimal roasting conditions, the fluorine could be stably solidified into CaF, and lithium could be converted

Platinum group elements (PGEs) are very important for the modern world, and they are used in many applications due to their physical and chemical properties that cannot be found in other naturally occurring elements. This means that the availability of PGEs now and in the future is very crucial. However, research has indicated that PGEs are at the edge of becoming scarce due to gradually depleting

This study presents a systematic summary on the depressing effect of polysaccharides on some polar minerals, revealing that the order of their depressing strength on some polar minerals was primarily associated with the surface properties of the minerals, showing a limited correlation with the structure of polysaccharides. Subsequently, the selective depressing mechanism of polysaccharides on polar

This study focuses on the parameters necessary for the successful deployment of intelligent control systems for flotation processes, focusing on froth surface characteristics. Depth information is not available for conventional 2D features extracted from single froth images, thereby constraining their capacity to fully capture froth surface characteristics. To overcome this limitation, this study proposes

A methodology is presented for the back-analysis of convergence measurements in deep tunnels to determine the constitutive parameters of the surrounding rock mass. Since increasing deformations and stresses with time are due to both the face advance and the time-dependent behavior of the ground, the two effects must be considered during the excavations. To that end, an analytical solution assuming

Analysis of compressive wellbore failure, or breakouts, is one of the primary methods of constraining the maximum horizontal stress in deep boreholes. To estimate stress using the observation of breakouts, one needs to measure the breakout width from image logs and use a failure theory to predict the stress that led to the development of the measured breakout. Most commonly, Mohr–Coulomb failure criterion