Mineral Beneficiation Research Articles

Harnessing Microbes for Enhanced Flotation Technology: A Review on Sustainable Mineral Beneficiation

Harnessing Microbes for Enhanced Flotation Technology: A Review on Sustainable Mineral Beneficiation

Effective Outlier Detection for Ensuring Data Quality in Flotation Data Modelling Using Machine Learning (ML) Algorithms

Froth flotation, a widely used mineral beneficiation technique, generates substantial volumes of data, offering the opportunity to extract valuable insights from these data for production line analysis. The quality of flotation data is critical to designing accurate prediction models and process optimisation. Unfortunately, industrial flotation data are often compromised by quality issues such as outliers that can produce misleading or erroneous analytical results. A general approach is to preprocess the data by replacing or imputing outliers with data values that have no connection with the real state of the process. However, this does not resolve the effect of outliers, especially those that deviate from normal trends. Outliers often occur across multiple variables, and their values may occur in normal observation ranges, making their detection challenging. An unresolved challenge in outlier detection is determining how far an observation must be to be considered an outlier. Existing methods rely on domain experts’ knowledge, which is difficult to apply when experts encounter large volumes of data with complex relationships. In this paper, we propose an approach to conduct outlier analysis on a flotation dataset and examine the efficacy of multiple machine learning (ML) algorithms—including k-Nearest Neighbour (kNN), Local Outlier Factor (LOF), and Isolation Forest (ISF)—in relation to the statistical 2σ rule for identifying outliers. We introduce the concept of “quasi-outliers” determined by the 2σ threshold as a benchmark for assessing the ML algorithms’ performance. The study also analyses the mutual coverage between quasi-outliers and outliers from the ML algorithms to identify the most effective outlier detection algorithm. We found that the outliers by kNN cover outliers of other methods. We use the experimental results to show that outliers affect model prediction accuracy, and excluding outliers from training data can reduce the average prediction errors.

Novel approach to locate micro-scale mineral regions of interest in real ores

The surface of minerals plays a pivotal role throughout the process of mineral beneficiation and utilization. Studies on surface properties, such as surface chemistries, of mineral phases of interest in real ores enable the selective separation of minerals, thereby enhancing the utilization of mineral resources. Nevertheless, obtaining specific mineral phases, especially for finely disseminated or poorly crystalized minerals, from real ores without altering their surface chemistries remains a challenge. The challenge also persists in investigating the same micro-scale mineral region in real ores using various surface characterization techniques, such as scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). This paper proposes a novel approach and procedures for locating micro-scale mineral regions of interest in real ores based on a three-dimensional coordinate system etched onto the ore surface using laser etching technology. A copper-nickel ore from Jinchuan, China, served as an illustrative example, with the finely disseminated chalcopyrite and pentlandite regions in the real ore sample being located and investigated using SEM and XPS. The approach presented in this study enables the in-situ detection of surface chemistries of specific mineral phase in real ores, ensuring the homogeneity and in-situ nature of the obtained surface chemistry data. This approach holds considerable promise, especially in the investigation of surface chemistries of minerals with fine dissemination and poor crystallization.

AgCl/g-C3N4/Ti-MOFs photocatalytic composite for visible light degradation of xanthate derived from mineral processing industries

Large amounts of xanthate wastewater generated from mineral beneficiation significantly threaten the ecological environment. MOF photocatalysis is considered as a promising method for the removal of xanthate that is environmentally friendly and has high efficiency. However, the defects in MOFs limit their large-scale application due to poor visible light absorption efficiency and stability in water. In this study, a novel composite material composed of g-C3N4/AgCl/Ti-MOFs was prepared, and the catalytic degradation effect of butyl xanthate solution under different catalyst ratios and reaction conditions was investigated. The results showed that the composite could still maintain excellent catalytic performance (degradation rate of 99.5% within 90 min) under xenon light and low dosage. The characterization results showed that this excellent photocatalytic performance could be attributed to the following three points: 1) The material could absorb up to 670 nm visible light absorption capacity; 2) excellent stability was achieved (86% degradation efficiency after six cycles); and 3) the Schottky junctions formed by Ag0 and other materials in the composite increased the transfer rate of e−/h+. The possible photodegradation mechanism was proposed according to UV–vis DRS and trapping experiments.

Research the slurry thickening efficiency of aluminum companies in Vietnam using experimental settling column system

The thickening is the process of increasing the solid fraction in the slurry. The purpose of the process is to obtain a thicker sludge product and to obtain an overflow product with a minimum solid amount. The equipment used are traction thickener, cable thickener, caisson thickener, tray thickener, E-Cat thickener, lamella thickener, etc. This stage plays an essential role and greatly affects operations in mineral beneficiation factories. However, this is a problem for Aluminum companies in Vietnam because the amount of particles passing 1 mm is significantly higher than the design, leading to the overloading of thickeners. The overall productivity of the factories was affected and seriously reduced due to not being able to ensure the amount of feeding coarse particles and having to stop the operation to fix the problem. The requirement is to find and apply advanced technologies to improve the sedimentation process. This article presents the characteristics of bauxite slurry in Daknong and Lamdong companies. The amount of fine particles passing 0.02 mm reaches more than 62% (in the case of Daknong) and 72% (in the case of Lamdong) with the main minerals (gibbsite, goethite, kaolinite, ilmenite, etc.). On that basis, the survey was implemented to define the optimal type of flocculant aids (NALCO 85035 and HA - LB 080), flocculant dosage (40 grams/tons), and pH of the sludge (6.5 – 7). The obtained underflow product has a solid phase concentration of over 35% and the overflow has an amount of solid/water of less than 100 mg/l. Research was conducted on an experimental settling column system and it was recommended to pre-test a Lamella high-performance thickener for further research.

Detail mineralogical study and geochronological framework of Bayan Obo (China) Nb mineralization recorded by in situ U-Pb dating of columbite

The Bayan Obo deposit is world-famous for its giant rare earth reserves, and also accompanied with 2.2 Mt Nb2O5 resources at an average grade of 0.13 %, renowned as the second largest Nb deposit globally. Previous studies have focused on the origin of carbonatite (igneous/sedimentary), and variation composition during evolution, as well as its super-enrichment of light rare earth elements (LREE), while the metallogenic mechanism of niobium is being overlooked despite the identification of plenty Nb-bearing minerals. In this study, we identify four types of columbite as major Nb-bearing minerals, instead of pyrochlore in the west pit of Bayan Obo. Detailed mineralogical study has revealed large primitive columbite (Clb1-I, 100–200 μm) is hosted in the coarse-grained Fe-dolomite carbonatite (FeO = 5.46–10.47 wt%), being an ideal target for future mineral beneficiation. Those columbites (Clb1-I) are featured by lowest Sr, Y, and ∑REE but enriched in iron in composition, revealing its magmatic origin. Sieve-textured columbite (Clb1-II, ∼100 μm) dispersed in the fluorination and chloritization dolomite carbonatite, with a U–Pb age of 1359 ± 31 Ma, contemporary with ages of the regional carbonatite magma intrusion and rift-related magmatism, indicating niobium being sourced from mantle-derived carbonatite. The occurrence of fluorite as inclusions in Clb1-I indicates the solubility of Nb was enhanced by fluxes, and the columbite saturation was easily achieved during the carbonatite magma evolution into ferroan carbonatite. Strong fenitization metasomatism further locally concentrated columbite either within the mineral assemblages of pyrite + phlogopite + allanite (Clb2) or in the mica-dominated fenite (Clb3), and crystallized at 346 ± 18 Ma and 284 ± 16 Ma, respectively. The latter metalogenetic epoch is accordant with late Permian granitic magmatism event (ca. 280 Ma) while the former age may attribute to its occurrences related to the early Paleozoic arc-continent collision. Differ from pristine columbite (Clb1-I and Clb1-II), the metamorphic columbite (Clb2 and Cl3, especially Clb3) are enriched in Ta (1803–4092 ppm), Y (560–2029 ppm) and ∑REE (720–6317 ppm) content, probably suggesting the highest degree of evolution. The similar metallogenesis framework between Nb and REE, combined with the coexistence of columbite and REE minerals assemblages, implies the spatial and temporal coupling of Nb and REE mineralization. This first innovative and systematic mineralogical and geochronological work directly constrains the nature of Mesoproterozoic mantle-derived carbonatite with fertile Fe and fluxes, and the Paleozoic and Permian fenitization metasomatism, are the major factors contribute to the metallogenic specialization of niobium in Bayan Obo.

Removal of Pb (II) and Zn (II) in the mineral beneficiation wastewater by using cross-linked carboxymethyl starch-g-methacrylic acid as an effective flocculant.

The cross-linked carboxymethyl starch-g-methacrylic acid (CCMS-g-MAA) was prepared by using grafting and micro-cross-linking in the one-pot preparation process. CCMS-g-MAA presented high removal capacity of Pb (II) of 57.13 mg/g at pH = 4 and high removal capacity of Zn (II) of 51.41 mg/g at pH = 5 by using a sample dosage of 0.68 g/L. Characterization results of FTIR, TG, and XRD illustrate that methacrylic acid and sodium tri-metaphosphate were successfully introduced into the structure of carboxymethyl starch. SEM characterization presented that the sample particles were amorphous aggregates with surface voids, which was favorable for the adsorption of heavy metal ions from wastewater. Adsorption isotherm results indicated that Freundlich equation could be better used to describe the adsorption process of metal ions on CCMS-g-MAA. The adsorption kinetic results indicated that the pseudo-second-order model is more suitable to describe this removal process. XPS results indicated that metal ions interacted with functional groups on the surface of flocculant, especially carboxyl groups. The removal process may be purposed that metal ions were adsorbed by porous material, and then combined with surface functional groups of the flocculant via electrostatic interaction, chelation or ion exchange. Subsequently, metal ions were separated from the wastewater with flocs precipitated in the bottom of solution via bridging and patching. The obtained results illustrated that CCMS-g-MAA was an effective material for the treatment of wastewater containing polymetallic ions besides mineral beneficiation wastewater supported by its excellent regeneration.

ФАКТОРИ ІНВЕСТИЦІЙНОЇ ПРИВАБЛИВОСТІ УКРАЇНИ

The article examines factors of Ukraine's investment attractiveness and ways of its activation. The modern legislative regulation of the activation of investment activities and the statistical dynamics of investments in the domestic economy are considered. It was noted about the effective legislative incentives of the laws of Ukraine "Regarding risk insurance of investments in Ukraine against war risks" and "On state support of investment projects with significant investments in Ukraine". The main tasks of the legislative decisions of the government during the full-scale military invasion of the occupiers are the activation and support of the innovative environment in Ukraine, the attraction of strategic investors to the domestic economy, and the provision of state support for large investment projects. This especially applies to such branches of the national economy as processing industry, extraction and beneficiation of minerals, transport, logistics, health care, etc. But this support will refer to large investment projects, namely, investment amounts must be equivalent to 12 million euros and the term of implementation of such projects should not exceed 5 years. The most active international companies are noted. Guarantees offered by the domestic government to foreign investors are given. Actual and planned reinvestments since the beginning of the military invasion of Ukraine are given. The international rankings of Ukraine are given. According to the rating compiled on the basis of research by Aswat Damodaran from the Stern School of Business at New York University, Ukraine is among the 20 countries in the world with a high investment risk. The rating was formed with the factors of political risk, economic structure, economic growth prospects, fiscal flexibility, debt burden of the public administration sector, stability of the financial sector, flexibility of monetary policy and gross and net external debt. The areas of activation of investment attractiveness in Ukraine are recommended - in the state and banking systems, and in the sphere of regulation of the market environment.

Study of the influence on potassium chloride enrichment technology in potassium ore

Due to the fact that the rich reserves of potash minerals are decreasing in the world, scientific research is being carried out on the development of effective technologies for beneficiation of minerals containing a small amount of potassium. In this regard, to study the mineralogical composition of low-grade potassium ores of the Tyubetagan mine, to conduct theoretical analysis of the galurgic method of beneficiation and to carry out research in laboratory conditions, to study the influence of various technological parameters on product output and to find optimal conditions, to develop a technological scheme of beneficiation of low-grade sylvinite ores by the galurgic method special attention is paid to the output. In this study, the mineralogical composition of potash ores of Tubegatan mine was studied and methods of beneficiation were proposed according to the relationship between the content of KCl, NaCl, insoluble residue and particle size of potash ores.

Exploration and Physicochemical Characterisation of Rayfield-Jos Alluvial Columbite Deposit for Effective Mineral Beneficiation and Value Metal Recovering of Niobium and Tantalum

Exploration and Physicochemical Characterisation of Rayfield-Jos Alluvial Columbite Deposit for Effective Mineral Beneficiation and Value Metal Recovering of Niobium and Tantalum

Exploration and physicochemical characterisation of Rayfield-Jos alluvial columbite deposit for effective mineral beneficiation and value metal recovery of niobium and tantalum

Exploration and physicochemical characterisation of Rayfield-Jos alluvial columbite deposit for effective mineral beneficiation and value metal recovery of niobium and tantalum

Influence of the leakage in air supply networks on the efficiency of application of pneumatic backfill equipment

Purpose. Determining the influence of the degree of pneumatic energy losses in the non-hermetic air supply network on the efficiency of using installed equipment in the pneumatic method of waste utilization from mining and beneficiation of minerals. To achieve this purpose, a tightness control device was developed using the method of fixed volumes. Methods. Using the molecular-kinetic theory of gases, the thermodynamics and hydrodynamics laws, the characteristics of an open thermodynamic system under excess pressure and with a degree of a capillary-type leakage are investigated. Pneumatic energy losses in the pneumatic supply pipeline are determined by the mass of compressed air leaked due to its poor tightness. Findings. The peculiarities of the tightness control of hollow products by the method of fixed volumes have been summarized. The dependences of non-production losses of compressed air and the corresponding pressure drop on the geometric characteristics of the air supply pipeline, the leakage in supply pipeline, and the time of assessing the degree of leakage have been determined. Originality. For the first time, the relationship between the parameters of compressed air in an open thermodynamic system under excess pressure during air leakage and its heat exchange with the environment has been revealed. The influence of compressed air leakage in air supply networks on the efficiency of using vibration-pneumatic machines with an annular ejector in backfill technologies has been determined. Practical implications. The research results can be used to improve the existing or develop the new technological schemes of air supply equipment that use pneumatic energy at mining and metallurgical enterprises. Minimization of energy consumption can significantly expand the scope of application of pneumatic backfilling method.

Investigation on enhancing classification of moist material by variable vibration intensity elastic screening

In mineral beneficiation, screening is critical for classifying materials. There are problems with low screening efficiency and adhesion and accumulation of material during the screening process of moist material. So, the process of enhancing the classification of moist material by an elastic screen surface with variable vibration intensity (ESSVVI) was investigated in this paper. The feeding speed of material was optimized during screening, and the synergistic effect of multi-parameters was further investigated by response surface methodology (RSM). The results showed that this screen surface could achieve elastic screening with variable vibration intensity, effectively overcome the moist material adhesion, and resolve the issue of material accumulation. The screening efficiency reached the maximum at 10.00 t·h−1·m−2 feeding speed. The impacts of screen body amplitude, frequency, and feeding speed on elastic screening performance with variable vibration intensity were found significant, and there were significant interactions among these parameters. This work can provide a reference to enhance the classification of moist material.

A New Route of Roasting-Flotation-Leaching for the Beneficiation of Ti-Bearing Minerals from Altered Vanadium Titanomagnetite

In this work, a complete beneficiation technical route combining physical and chemical methods, namely a roasting-flotation-leaching scheme, is proposed to produce a qualified grade Ti-concentrate from altered Vanadium titanomagnetite (VTM) ore. Based on the character of the ore sample, it is recommended to recover the Ti-bearing minerals, ilmenite and anatase, as composite mineral. Pretreatment experiments indicate that the oxidation roasting (800 °C) and acid washing methods increase the flotation indexes significantly. Flotation condition tests show that the optimal conditions are a grinding fineness of −0.045 mm 83%, sulfuric acid dosage of 2000 g/t, water glass dosage of 1500 g/t, oxalic acid dosage of 200 g/t, and EM328 dosage of 1500 g/t. An open flotation circuit test obtains a flotation concentrate with a TiO2 grade and recovery of 38.30% and 25.99%, respectively. A leaching exploration test shows that the TiO2 grade of the flotation concentrate can be improved to 53.90%. XRD analyses reveal that the ilmenite in the VTM ore is converted into anatase and rutile during the roasting process at 600–800 °C, but pseudobrookite begins to form at 900 °C. Compared to the flotation concentrate, it is confirmed that the content of Ti-bearing minerals is increased significantly in the leaching residue.

Iron, copper, and rare earth minerals beneficiation in an IOCG type deposit

ABSTRACT The sample of the Sineqan mine (Arak, Iran), containing 16.5% Fe, 0.13% Cu, 475 ppm Ce, 446 ppm La, and 134 ppm Nd, was characterised and processed to investigate the possibility of separating iron, copper, and REE minerals. Microscopic studies showed that the main minerals in the sample include magnetite, hematite, goethite, specularite, pyrite, and chalcopyrite, while the gangue minerals consist of quartz, clay minerals, and carbonate minerals. The results of heavy liquid studies using Bromoform showed that by reducing the particle size from 1180 to 300 micrometre, 76.6% of iron and 72.76% of copper went into the heavy section, while 77.9% of REEs entered the light section. The magnetic separation experiments revealed that higher magnetic field intensity increased the recovery of iron, copper, and REEs with no separation between them. In summary, the results indicate that REEs are primarily present in the light section due to their association with sphene silicate mineral, and gravity separation demonstrated superior performance in terms of both recovery and selectivity. The results of this research are significant for the processing of iron oxide-type deposits that contain copper and REEs.

Regional Mineral Beneficiation Policy Interventions in the SADC: Stakeholder Perspectives

The Importance of Mineral Beneficiation: Mining is a significant economic activity in most Southern African Development Community (SADC) countries, and mineral beneficiation has been identified and controversially discussed as one of the possibilities for industrialisation. The purpose of this article is to study mineral beneficiation policies and practices in the SADC countries with regard to the regional developmental agenda. Methodology and Interventions: With many member countries being economically too small to muster the human and financial resources, the recently adopted Regional Mining Vision (RMV) envisages interventions at a regional level. This study followed a qualitative approach with semi-structured interviews across the region mainly in English and seldom in French. Principal Results: Twenty-five semi-structured interviews were conducted with experts from SADC member countries during the 2019 Mining Indaba. Participants were divided on whether beneficiation should be carried out nationally or in the SADC region. While beneficiation could support value-keeping, key challenges named were infrastructure development (i.e. energy, water), scarce skills, access to technology and related cost, but also lack of free trade and movement. Conclusion: We submit that a more integrated beneficiation strategy for the SADC region, as was being developed through the RMV, would indeed be relevant in the future.

Arsenic Removal and Iron Recovery from Arsenic-Bearing Iron Ores by Calcification-Magnetic Roasting and Magnetic Separation Process.

Extracting iron while minimizing the health and environmental risks associated with arsenic contamination necessitates the removal of arsenic from arsenic-bearing iron ores to ensure a safe and sustainable supply of this metal for industries. The beneficiation of iron minerals and arsenic-bearing minerals from arsenic-bearing iron ores with a calcification-magnetizing roasting and low-intensity magnetic separation (CMR-LMS) process is investigated in this work. The results show that the process is successful in extracting iron minerals and eliminating arsenic-containing minerals. The roasting involves two key steps: calcification and magnetizing, which change hematite and goethite into magnetite and arsenic-bearing minerals into calcium arsenates. The process's separation efficiency of the CMR-LMS is closely linked to the parameters such as roasting temperature, roasting time, coke, alkalinity, and the liberation of gangue minerals from iron minerals. Through grinding and secondary magnetic separation, the iron minerals and gangue components, as well as arsenic, in roasted sand can be further separated. The optimum procedure results in a high-grade iron concentrate with an iron assay of 65.65%, an Fe recovery rate of 80.07%, and an arsenic content of 0.085%, while achieving a 93.29% As removal rate from the original ore that has 45.32% Fe and 0.70% As.

Dielectric barrier discharge plasma-coupled rare-earth modified Er3+-BiOI catalytic materials for degradation of organic pollutant benzohydroxamic acid in mineral beneficiation waster: Performance, degradation pathway, and its mechanism

A dielectric barrier Discharge (DBD) plasma catalytic system for synergistic degradation of benzohydroxamic acid (BHA) was established. A series of Er3+-BiOI samples doped with rare earth elements (Er3+) were prepared by the hydrothermal synthesis method. The characterization showed that Er3+-BiOI had a microglobular structure assembled by nanosheets, and the specific surface area of Er3+-BiOI was larger than that of pure BiOI. The degradation performance showed that in the DBD/Er3+-BiOI system, the highest BHA degradation efficiency reached 96.3 % with 4 % Er3+. Compared with the DBD-BiOI system and the single DBD system, the degradation efficiency of BHA increased by 9.1 % and 17.5 %, respectively. Meanwhile, the kinetic constants and cofactors were also the highest, at 3.36 and 2.88 times the DBD-BiOI system, respectively. The radical capture experiments showed ∙OH, ∙O2−, and cavities play a key role in the degradation of BHA, while O3, H2O2, e−, and H+ promote the degradation of BHA. The intermediates in the degradation of BHA were determined by LC-MS, and the possible degradation pathways of BHA were predicted. Finally, the degradation mechanism of BHA in the DBD/4 % Er3+-BiOI system was proposed.

A Competitive Framework for Mineral Beneficiation and Value Addition in Zimbabwe

The development of mineral beneficiation and value addition has the potential to drive sustainable socioeconomic development in Zimbabwe. However, the country has been facing challenges in fully leveraging its mineral resources endowment for economic growth. This paper aims to address this issue by presenting a comprehensive framework for mineral beneficiation and value addition in Zimbabwe. The framework was developed using a mixed-methods approach that involved a literature review, stakeholder consultations, and data analysis. The objectives of the framework are to enhance mineral beneficiation and value addition, promote sustainable socioeconomic development, and create economic opportunities for local communities. The framework comprises a set of strategies and policies aimed at addressing the challenges facing the mineral sector, including inadequate infrastructure, limited technological capacity, and inadequate financing. The framework also emphasizes the need for stakeholder collaboration, human capacity building, and the adoption of environmentally sustainable practices. The paper concludes by highlighting the potential benefits of the framework, including increased employment, foreign exchange earnings, and overall economic growth, and calls for its adoption by policymakers and stakeholders in Zimbabwe.

Hierarchical Intelligent Control Method for Mineral Particle Size Based on Machine Learning

Mineral particle size is an important parameter in the mineral beneficiation process. In industrial processes, the grinding process produces pulp with qualified particle size for subsequent flotation processes. In this paper, a hierarchical intelligent control method for mineral particle size based on machine learning is proposed. In the machine learning layer, artificial intelligence technologies such as long and short memory neural networks (LSTM) and convolution neural networks (CNN) are used to solve the multi-source ore blending prediction and intelligent classification of dry and rainy season conditions, and then the ore-feeding intelligent expert control system and grinding process intelligent expert system are used to coordinate the production of semi-autogenous mill and Ball mill and Hydrocyclone (SAB) process and intelligently adjust the control parameters of DCS layer. This paper presents the practical application of the method in the SAB production process of an international mine to realize automation and intelligence. The process throughput is increased by 6.05%, the power consumption is reduced by 7.25%, and the annual economic benefit has been significantly improved.