Mineral Beneficiation Research Articles

Impacts of process and design conditions of dry stirred milling on the shape of product size distribution

A grinding technology should consider the physical properties of the material, i.e., size, shape, which have effects on the product specifications, i.e., quality, strength or overall process efficiency. In this respect, this study aimed at evaluating the variations in the shape of product size distribution of a stirred media mill as the attention on this technology has been growing in the recent years. Within the scope of the research, series of grinding tests were performed at different operating conditions, i.e. bead size, bead type, tip speed, feed rate and mill design, with a laboratory scale continuously operated horizontal stirred media mill. The investigations proved that the use of coarser and denser beads as well as adjusting higher tip speeds resulted in obtaining narrower product size distribution for the same mean size. For a better understanding of the process, the stress energy and mean residence time evaluations were also undertaken. It was found that the stress energy and its normalization with the mean residence time are directly proportional to the slope of the distributions. As a conclusion, the dry stirred media mill is able to adjust the shape of the distribution, which may be beneficial regarding to the mechanical properties of the end products (cement manufacturing) or efficiency of the mineral beneficiation processes.

The Benefits of Mineral Beneficiation to Liberia's Economy

It is obvious that, for any country that is anticipating to be successful in today's end-users' community, that country's sectors' managers need to apply some sufficient efforts in order to render assistance to the indigenous mining companies to outcompete the other firms in the region. Among many possible activities, cost reduction in mineral beneficiation is regarded as one of the core areas presenting enormous opportunities for the West country, Liberia. The country like Liberia who is endowed with an impressive stock of mineral reserves and has traditionally relied on mining, namely iron ore, gold, and diamonds, as a major source of income is not exempted.

THE EFFECTIVENESS OF PHYSICAL SEPARATION PROCESS FOR THE ALLUVIAL TIN (HEINDA) ORE, MYANMAR

Mineral beneficiation is a process by which valuable constituents of an ore are concentrated through a physical separation process. In the present investigation, tin ore samples were collected from the Heinda tin mine, Thanintharyi region, Myanmar. Heinda mine is tin placer deposits which are located about 50 Km east of Dawai, Tanintharyi, Myanmar. The mine can be reached by road from Poo Nam Ron checkpoint, Kanchanaburi Province, Thailand. In this study, particle size analysis (PSD) was carried out over the range of - 6.7 mm and +0.075 mm in 9 different mesh sizes. The operating variables used to determine the recovery effectiveness of the jigging and shaking table include; particle size, stroke, table slope, and dilution ratio, then the percent recovery of tin concentrate was evaluated by applying X-ray fluorescence (XRF). The results showed that the tin mineral concentrate of the jig separator is 70.7% and the shaking table is 49.8%. The cassiterite recovery processes were conducted by using physical separation processes and the discounted cash flow model (DCF) for an economic analysis of the project. In this study, the internal rate of return (IRR) is 11.45percent which is higher than the discount rate of 8 percent, and NPV is 790,886,832.61 US $. The payback period of the project is equal to 8 to 9 years of project life for 30 years. Consequently, the Heinda tin ore project is proven feasible.

Recovery of Iron values through conventional beneficiation techniques from Banded Hematite Jasper of Eastern India with special reference to mineralogical and chemical characterization

Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean grade iron ores of India like BHJ and BHQ needs to be utilized through suitable beneficiation techniques. Methods: Banded Hematite Jasper (BHJ) sample of Bonai-Keonjhar belt (BK belt), Odisha, India assayed 35.3 % Fe, 47.1% SiO2 and 0.96% Al2O3 was investigated in respect of mineralogy, liberation characteristics and chemistry to finding out its optimum beneficiation potential. In the present investigation, efforts have been made to characterize the BHJ sample with reference to its beneficiation response. The sample was subjected to various beneficiation operations like Jigging followed by hydrocyclone, two-stage tabling and magnetic Separation. Findings: Mineralogical studies indicate that quartz and hematite are the major mineral phases, whereas goethite, martitized magnetite and clay (kaolinite) are present in very minor amounts. The liberation characteristic indicates that the average band thickness of Iron bearing mineral is of 1680 microns and 80% of the iron bearing minerals are liberated at -105 microns size. The two stage tabling of jig concentrate with desliming gives better outcome as compared with direct tabling of jig concentrate. An iron ore concentrate assayed 64.5% Fe, 5.6% SiO2 and 0.80% Al2O3 with wt% recovery of 23.2% can be obtained from two stage tabling. Another concentrate from magnetic separation of table middling and hydrocyclone assayed 63.2% Fe, 7.2% SiO2 and 0.7% Al2O3 with wt% recovery of 12.4% can be obtained. Novelty/ Application: Here a conventional beneficiation flow sheet is developed with a finding that, in order to beneficiate ore like banded hematite jasper (BHJ), an integral characterization approach is very much essential. Both of the concentrates obtained through the flow sheet assayed 64% Fe, 6.2% SiO2 and 0.7% Al2O3 with a wt% recovery of 35.6% can be utilized as a feed stock for pellet making in iron ore industries. Keywords: Banded Hematite Jasper (BHJ); mineral beneficiation; wet high intensity magnetic separator (WHIMS); jigging; Bonai-Keonjhar belt

COMPARISON OF PARTICLE SHAPES OF CONVENTIONALLY GROUND BARITE, CALCITE AND TALC MINERALS BY DYNAMIC IMAGING TECHNIQUE: A REVIEW

Shape of particles made by grinding is one of the important measures for determining the utilizations of industrial minerals namely barite, calcite, and talc particles, particularly at production (like coating pigments, paints, rubber and paper) and processing stages (beneficiation by flotation). Therefore, measurement of particle characteristics is a critical issue in the development and control of industrial mineral products in most of the industries for some demanding applications. Ball and rod mills are commonly used as conventional grinding mills to produce a controlled grind size for the flotation circuit in the beneficiation of industrial minerals. Dynamic Image Analysis (DIA) offers reproducible results of a huge number of particles for some industrial minerals namely, barite [1], calcite [2] and talc [3] particles, whose shapes are crucial for some industries utilized as fillers. Thus, this review is about the comparison of shape values in terms of circularity (C) and bounding rectangle aspect ratio (BRAR) determined by the real time DIA. It was found that the shape results of the previous studies for the same samples by SEM measurement [4] were in good agreement with DIA results. It was concluded that the more rounded particles were encountered in the rod milled products for calcite and barite minerals. On the other hand, the more elongated particles were found in the ball milled products for talc mineral. It was attributed to the material type since the same mills were used for all tests. Hence, DIA can be used as a useful tool, which is easy, fast and highly accurate to control the particle shape distributions whether the required powder is fit for use

The Comparison of Main Copper Sulphide Minerals Beneficiation Under Laboratory and Industrial Conditions at the KGHM Concentration Plant

The Zechstein copper ore deposit located on the Foresudetic monocline has a complex geological structure both in lithological and mineralogical aspects. The significant variability in quantity and quality of minerals deposited in the ore bed is one of the factors determining the susceptibility of copper ore to beneficiation based on flotation, which is carried out in the KGHM Concentration Plant. Based on the algorithm developed, flotation experiments on a laboratory scale have been conducted to predict the upgrade rates under industrial conditions. This paper provides the results of the mineralogical examination of the flotation products performed by one of the KGHM Concentration process lines and compares the beneficiation of various copper sulphide minerals. The results of the laboratory tests have been compared with the results of sampling carried out simultaneously at the process line. A procedure has been proposed to develop equations defining the industrial upgradability curves for copper sulphide minerals under the KGHM Concentration Plant conditions.

An analysis of Zimbabwe's comparative advantage in the beneficiation and value addition of minerals

Over the past decade, Zimbabwe has implemented various policies in the form of export tariffs and embargoes to stimulate downstream mineral beneficiation. The policies failed to yield tangible results due to, among other factors, inadequate due diligence regarding the capability of the country in terms of its factor endowments to support downstream beneficiation. Additionally, lack of Investment in the country's downstream industries as reflected in its capital stock contributed significantly to poor domestic demand for raw materials. In light of the above, different studies have established that there are few examples where mineral beneficiation oriented policies have yielded positive results in mineral-rich countries. The reasons for failure include lack of comparative advantage and economic viability of the technologies adopted. Related studies have also shown that the similarity of factor intensities and technology across sectors stimulates structural transformation in developing countries. This paper uses the factor endowment approach to evaluate Zimbabwe's comparative advantage in the downstream beneficiation of minerals. The country's arable land, physical capital stock and human capital are used as a measure of its capability to produce beneficiated products along the mineral value chain. By matching Zimbabwe's arable land, capital stock and human capital to the revealed factor intensities for different products, the mineral related products that the country has a comparative advantage in producing are identified and presented.

Investigating the Electrochemical Interaction of a Thiol Collector with Chalcopyrite and Galena in the Presence of a Mixed Microbial Community

High microbial cell counts have been recorded in sewage waters employed as process water in mineral beneficiation plants across the world. The presence of these microbes can negatively impact flotation performance through mineral passivation, although some microbes improve flotation performance as investigated in various bio-flotation studies. The current study aims to understand the electrochemical behaviour of minerals in the presence of a sodium ethyl xanthate (SEX) collector and microbes originating from a sulphide ore processing plant in South Africa. The electrochemical response was correlated to observe flotation performance. Mixed potential measurements were conducted in parallel to microflotation tests, to assess the hydrophilicity or hydrophobicity induced on sulphide minerals adapted to microbe-laden synthetic plant water. Sulphide minerals’ mixed potentials and interactions of SEX with sulphide minerals were dramatically reduced in the presence of the mixed microbial community (MMC). The observations were correlated with poor flotation efficacy noted in microflotation tests. These fundamental results shed light on how the adsorption of thiol collectors on sulphide minerals is adversely affected by microbes, prompting a discussion on flotation process monitoring when mineral beneficiation is conducted using microbe-laden water.

Study of Dry Mineral Separation Behavior in Dry Density Separators

Mineral dry density separation behavior (mineral beneficiation) involves segregation of high density particles and low density particles in the feed, i.e., in nutshell, mineral dry density beneficiation is density segregation in physics terms. In dry beneficiation, this density segregation is achieved using air as fluidized medium. Density segregation on dry separators can be achieved in two ways: (1) using minimum fluidization velocity differences and (2) using terminal velocity difference between different density particles. Dry separators based on minimum fluidization velocities follow two steps for dry beneficiation: (1) vertical density stratification and (2) horizontal segregation. Particles due to buoyancy, drag and gravitational forces get vertically density stratified and later frictional, gravity and external (vibrational, etc.) forces horizontally segregate different density particles. Dry separators based on terminal velocities follow single step for dry beneficiation of mineral, and air velocity in this type of dry density separators is maintained between terminal velocity of high density and low density particles. Velocity of air is higher for low density particles, which leads to higher drag and buoyancy forces to get pushed out of system with air and get collected at further distance than high density particles leading to density segregation. Mathematical models have been developed using force balance on particles and simulated in MATLAB for both type of separators to explain the physics of separation. Solutions to the simulated mathematical model equations are the particle trajectories of different density particles in the two dry separators. Iron ore is used as feed for studying separation futures in mathematical modeling on dry separators.

Efficiently removing cetyl trimethyl ammonium bromide from wastewater by graphene oxide

Cetyl trimethyl ammonium bromide (CTAB) containing wastewater from dressing plant may pose a detrimental threaten to mineral beneficiation and environment. The adsorption of CTAB in aqueous solutions by graphene oxide (GO) has been studied in this work. X‐ray diffraction, X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectrometer, and atomic force spectroscopy were used to characterize GO. The results indicated that the adsorption followed the Freundlich model could be well described by pseudo‐second order kinetic model. The adsorption capacity was much bigger than activated carbon and many natural clay minerals. The adsorption process was endothermic, and the adsorption mechanism of CTAB onto GO was proven to be controlled by surface complexation, hydrogen bonding, and electrostatic attraction.

DOMESTIC BENEFICIATION POLICY IN MINING SECTOR: A CASE STUDY OF INDONESIA

The purpose of this study is to compare beneficiation policy between oil, coal, gas and metal mining sector in Indonesia. The empirical fact shows Indonesia’s Constitution of 1945 stated that natural resources in Indonesia are controlled by the state to be exploited to the greatest benefit of the people. However, Indonesia’s prevailing law has varied interpretation of this term. This is shown in differentiation of beneficiation policy between oil, coal, gas and metal mining sector in Indonesia despite the same philosophical basis of the utilization itself. This study explains the difference of interpretation under Indonesia’s Law regarding natural resources beneficiation and how it is furtherly implemented in the sector. This research is normative in nature, using literature study to gather data. The conclusion of this study is metal mining sector is the only sector whom ready to implement domestic mineral beneficiation obligation. While in other sector, Indonesian government and mining stakeholders are not ready to take the risks to establish beneficiation dependency.

Análise dos impactos no uso e ocupação do solo associados a possível ruptura da Barragem do Itabiruçu, Itabira (MG)

O processo de beneficiamento dos minerais gera como subproduto os rejeitos, geralmente dispostos em barragens de contenção, que podem possuir um alto risco potencial associado, provocando significativos impactos ambientais quando há ruptura dessas estruturas. Por isso, em 2010, foi criada a Política Nacional de Segurança de Barragens, que tem como um dos seus instrumentos o Plano de Ação de Emergência para Barragens de Mineração (PAEBM). No município de Itabira (MG) há um importante complexo minerador, em que parte do rejeito gerado durante o beneficiamento do minério de ferro é depositado na Barragem de Itabiruçu. Assim, esta pesquisa objetivou examinar o PAEBM dessa estrutura, caracterizando a mancha de inundação decorrente de seu possível rompimento, e analisar os prováveis impactos no uso e ocupação do solo. Para isso, foi utilizada a pesquisa documental, a partir da análise de imagens de satélite, do PAEBM da Barragem do Itabiruçu e do mapa contendo a mancha de inundação. Com estes dados, foi possível identificar que a mancha resultante de uma possível ruptura da barragem ocuparia uma área de 8,9 km2 do município, incluindo ao longo do seu percurso 13,2% do perímetro urbano e 67,6% das áreas de pastagem, originando assim impactos tanto ambientais quanto socioeconômicos. Além disso, foi constatado que o sistema de alerta implantado não alcançou em todos os pontos os decibéis exigidos pela legislação. Assim, recomenda-se o desenvolvimento de novas pesquisas direcionadas à criação de técnicas mais eficientes de alerta e na eliminação ou minimização dos impactos decorrentes de um eventual rompimento.

Sequential decision-making in mining and processing based on geometallurgical inputs

Geometallurgy as a multi-disciplinary field has been applied at various levels in different operations. By linking the ore performance in mineral beneficiation processes to the ore block model, it supports estimating the value of a block before it is mined. Efforts in the classification of the ore into geometallurgical classes have led to a better understanding of the entire value chain. While classification provides a convenient tool for forecasting and visualization purposes, it simplifies the actual complexity of an ore body. In mining and process planning, sequential decisions are made to maximize an objective function or equivalently minimize a regret function. Using available information from geology or metallurgical test work, an optimal strategy can be found using tools from the machine learning community.In this study, a framework based on machine learning to maximize the use of such classifications for sequential decision-making is proposed. The concepts of reinforcement learning and bandit algorithms, offer powerful tools to explore and exploit different optimization strategies. In certain cases, theoretical guarantees about the performance of given methods can be obtained by regret bounds.Based on existing models of a porphyry copper deposit and an iron ore deposit, this study presents a methodology and different available algorithms to maximize an objective function that depends on a high number of variables and in the presence of noise or uncertainty in the models. Different numerical experiments provide a basis for discussion and comparison to human decisions. The hypotheses relative to each algorithm are discussed in relation to the mineral processing models.

Selective flotation of phosphorus-bearing ores

This paper presents the results of the beneficiation of a phosphorus-bearing mineral through selective flotation process. The chemical examination showed that the sample contain a low content of P2O5 12.5 % and significant amounts of rare earth elements (REE), %: yttrium - 0.01, lanthanum - 0.06, cerium - 0.09, neodymium - 0.03. The particle size distribution of the sample was performed, and each separated fraction was chemically analyzed. A detailed examination of the mineralog ical characteristics was conducted using automated mineral liberation analyzer (MLA). It has been shown that the apatite particles are mostly liberated in all fraction sizes. The maximum percentage of apatite polymineral aggregate was recorded in the grain size of -0.5 + 0.2 mm, mainly with nepheline and pyroxenes. The maximum percentage of apatite binary aggregate was noted in the grain size of -0.16 + 0.071 and -0.071 + 0.045 mm. Based on the obtained results, the size of the flotation feed was predetermined, which allowing the complete liberation of phosphorusbearing mineral (apatite) and avoiding over-grinding of the ore.

An environmentally friendly route for beneficiation of rare earth-bearing minerals by Pickering emulsification: adjusting the interfacial and formulation parameters

A proper process formulation for cleaner separation of rare earth minerals through Pickering emulsification: an alternative to flotation.

Study on Flotability and Surface Oxidation of Sulfide Minerals from the Tailing of an Iron-Copper Mine Using Electron Probe Microanalyzer

ABSTRACT With the depletion of high-grade ores, beneficiation of valuable minerals from mineral processing tailings attracts attentions of mining companies and researchers. Recovery of valuable sulfide minerals by flotation from the tailing of an iron-copper mine in central China was investigated in this paper. The surface oxidation status of sulfide minerals is an important factor influencing their flotation properties. Electron probe microanalyzer (EPMA) equipped with wavelength dispersive X-ray spectrometer (WDS) is an effective apparatus for characterizing solid surface (interface), which can analyze the composition and element distribution on the surfaces of sulfide minerals so as to understand their oxidation status. EPMA-WDS was employed to analyze the phenomenon responsible for the low flotation recovery of chalcopyrite and pyrite in this tailing. The research methodology is a useful reference for further work in the field of sulfide mineral surface analysis.

Constraining the Economic Potential of By-Product Recovery by Using a Geometallurgical Approach: The Example of Rare Earth Element Recovery at Catalão I, Brazil

Abstract Geometallurgy aims to develop and deploy predictive spatial models based on tangible and quantitative resource characteristics that are used to optimize the efficiency of minerals beneficiation and extractive metallurgy operations. While most current applications of geometallurgy are focused on the major commodity to be recovered from a mineral deposit, this contribution delineates the opportunity to use a geometallurgical approach to provide an early assessment of the economic potential of by-product recovery from an ongoing mining operation. As a case study for this methodology, possible rare earth element (REE) recovery as a by-product of Nb production at the Chapadão mine in the Catalão I carbonatite complex is used. Catalão I is part of the Alto Paranaíba igneous province in the Goias Province of Brazil. Currently, niobium is produced in the complex as a by-product of the Chapadão phosphates mine. This production is performed in the Tailings plant, the focus of this study. REEs, albeit present in significant concentrations, are currently not recovered as by-products. Nine samples from different stages of the Nb beneficiation process in the Tailings plant were taken and characterized by mineral liberation analyzer, X-ray powder diffraction, and bulk-rock chemistry. The recovery of REEs in each of the tailing streams was quantified by mass balance. The quantitative mineralogical and microstructural data are used to identify the most suitable approach to recover REEs as a by-product—without placing limitations on niobium production. Monazite, the most common rare earth mineral identified in the feed, occurs as Ce-rich and La-rich varieties that can be easily distinguished by scanning electron microscopy (SEM)-based image analysis. Quartz, Fe-Ti oxides, and several phosphate minerals are the main gangue minerals. The highest rare earth oxide content concentrations (1.75 wt % total rare earth oxides) and the greatest potential for REE processing are reported for the final flotation tailings stream. To place tentative economic constraints on REE recovery from the tailings material, an analogy to the Browns Range deposit in Australia is drawn. Its technical flow sheet was used to estimate the cost for a hypothetical REE production at Chapadão. Parameters derived from SEM-based image analysis were used to model possible monazite recovery and concentrate grades. This exercise illustrates that a marketable REE concentrate could be obtained at Chapadão if the process recovers at least 53% of the particles with no less than 60% of monazite on their surface. Applying capital expenditure and operational expenditure values similar to those of Browns Range suggests that such an operation would be profitable at current REE prices.

Artificial neural network modeling and experimental investigation to characterize the dewatering performance of a hydrocyclone

ABSTRACT Dewatering in mineral processing industries is of paramount importance as most wet beneficiation of minerals needs removal of water. For this purpose, we have evaluated a 50.8 mm diameter hydrocyclone in order to assess whether it can be used as a partial replacement for a thickener. A multi-layer perceptron based artificial neural network (ANN) model was developed to characterise the dewatering performance of a hydrocyclone using experimentally generated data for silica and magnetite. Parametric sensitivity analysis was undertaken by studying the influence of vortex finder diameter, spigot diameter and inlet pressure on dewatering performance. The ANN model predictions showed that solid recovery to underflow increases and water recovery to overflow decreases with increasing spigot diameter whereas solid recovery to underflow decreases and water recovery to overflow increases with increased vortex finder diameter. Both increase monotonically with increase in inlet pressure. The neural model prediction was successfully validated with the experimental data.

Selection of a Viable Upgradation Strategy Through Physico-chemical and Mineralogical Approach: A Case Study of Low Grade Barsua Iron Ore Fines

Detailed characterization study is the pioneer step for any mineral beneficiation scheme. A series of mineralogical and peterographic studies coupled with (Brunauer–Emmett–Teller) surface area, (atomic force microscopy), (laser diffraction particle size analyser), FTIR (Fourier transform infrared spectroscopy), contact angle measurement, zeta potential were carried out, and the findings about the mineralogical and physico-chemical nature of the sample have been described. This paper provides a guide on the proper selection of beneficiation route for iron ore with complex mineral assemblage (Hematite–Goethite–Laterite–Quartz–Kaolinite–Gibbsite). The beneficiation method, especially froth flotation process, potential after a thorough characterization is suggested analysed and the successful upgradation by froth flotation route is envisaged. Flotation results indicated that it is possible to achieve high grade iron concentrate along with lower silica, and alumina content providing a specific reagent regime/system for specific mineral assemblages.

Mineral beneficiation of nepheline syenite with combination of dry magnetic separation and flotation methods

Mineral beneficiation of nepheline syenite with combination of dry magnetic separation and flotation methods