Separation Of Ore Research Articles

A selective flotation of fluorite from dolomite using caustic cassava starch and its adsorption mechanism: An experimental and DFT Study

Due to the small difference in floatability between dolomite and fluorite, the problems of low grade of fluorite concentrate occur. It is very important to find a depressant that can selectively inhibit the floating of dolomite. As a natural polymer, starch is often used as a gangue depressant because of its low price and easy availability. In this paper, the effects of caustic cassava starch (CS) on the single mineral flotation performance of fluorite and dolomite and the flotation separation of mixed ore were studied. Its selective inhibition mechanism was investigated. The results of flotation tests with single minerals stated that the flotation of dolomite was vastly inhibited, while the fluorite was hardly affected when CS was added in flotation using sodium oleate as the collector. The concentrate grade of artificially mixed ore flotation fluorite reached 90.15%, and the recovery rate was 89.54%. The physical adsorption of CS on the surface of dolomite blocked the adsorption of hydrophobic sodium oleate on the surface of dolomite, thus depressing dolomite. The adsorption energy of dolomite and CS was much larger than that of fluorite and CS. This greatly deteriorated the flotation of dolomite and achieved flotation separation between fluorite and dolomite. The results demonstrate that CS is a promising depressant for dolomite in fluorite flotation.

Removal of Flotation Collector O-Isopropyl-N-ethylthionocarbamate from Wastewater.

Flotation collector O-isopropyl N-ethylthionocarbamate (IPETC) is widely used for separation of sulfide ores. Its removal from water by several oxidation processes was studied. Photocatalytic oxidation with air in the presence of iron salts, utilizing solar irradiation or artificial UV-A light is very efficient. Oxidation leads through the formation of O-isopropyl N-ethylcarbamate and several other reaction intermediates to total decomposition of organic compound in the final stage in 1 day. Similar results were obtained with a Fenton type oxidation with hydrogen peroxide and iron salts. Treatment with sodium hypochlorite yields mainly O-isopropyl N-ethylcarbamate. The formation of this compound in wastewaters can be of concern, since simple alkyl carbamates are cancer suspect agents.

An innovative technique for the separation of ion-adsorption high yttrium rare earth ore by Er (III) / Tm (III) grouping first

The current separation technique of ion-adsorption high yttrium (Y) rare earth ore (high-yttrium ore) using 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) and naphthenic acid (NA) has been confronted with low separation efficiency and high acid consumption. This is a consequence of the low selectivity and the difficulty of complete stripping of heavy rare earths (HREEs). Therefore, an innovative separation technique of high-yttrium ore was proposed. The leachate of high-yttrium ore was firstly divided into Erbium (Er) / Thulium (Tm) groups with P507-isooctanol followed by separating Y (III) from the high Y-enrichment of Er (III) group with sec-octylphenoxy acetic acid (CA12)-tri-n-butyl phosphate (TBP). The basic thermodynamics experiments and cascade extraction simulations were conducted to verify the feasibility of this technology. The results show that P507-15vol% isooctanol is superior to P507 in both stripping ability and separation selectivity of HREEs. The first cascade extraction for Er (III) / Tm (III) grouping with P507-15vol% isooctanol was simulated successfully, reducing acid consumption but obtaining high purity products. In theory, the second cascade extraction simulation designed for separating Y (III) with CA12-TBP could not only improve the separation ability between Y (III) and light rare earths (LREEs) but also shorten the extraction stages and reduce the production costs. All these results revealed that this two-step separation process probably provided a promising application prospect for separating high-yttrium ore.

Nanobubble assisted flotation separation of complex Pb–Cu–Zn sulfide ore – Assessment of process readiness

ABSTRACT A considerable difference exists between the flotation separation of artificial minerals and real low-grade ores processing where selectivity would be the main issue. Nanobubble-assisted (NB) flotation investigations have been mostly examined with pure materials and a narrow particle size range, less on complex sulfide ores. This study considered NB flotation for processing complex Pb-Cu-Zn sulfide ore in two different size ranges and various conditions to assess the process readiness. Metallurgical NB flotation responses (recovery, grade, kinetics, and selectivity index) were determined, compared to conventional tests. Outcomes revealed that an inclusive size fraction (−150 µm) could result in a higher selective process than a fine fraction (- 38 µm). In contrast, mass recovery and kinetics were higher for the fine one. In general, adding NBs compared to the conventional (CB) could improve the flotation metallurgical responses; however, the way NBs were generated would be key. NBs generated in the presence of frother (NBF) could produce higher mass and water recoveries while decreasing selectivity. In general, different setups’ flotation products showed the following selectivity order of Pb-Cu sulfides: NB>NBF>CB. These results opened a new approach for considering different NB generation conditions when they are going to use in various flotation stages.

Influence of Sodium Salts on Reduction Roasting of High-Phosphorus Oolitic Iron Ore

ABSTRACT The reduction roasting followed by magnetic separation process is considered to be a suitable method to treat the high-phosphorus oolitic iron ore. Currently, the dephosphorization mechanism of additives such as CaCO3, Ca(OH)2, Na2SO4, and Na2CO3 on the reduction roasting of the iron ore in which phosphorus occurs in apatite have been thoroughly studied. The effect of sodium salts (Na2CO3, NaCl and Na2SO4) on reduction roasting and magnetic separation of high-phosphorus oolitic iron ore containing phosphorus in iron oxides was investigated, and the mechanisms of sodium salts were expounded using XRD and SEM-EDS. The results show that the dephosphorization ability of sodium salts was in the order of Na2SO4> Na2CO3> NaCl>no sodium salts. Na2CO3 and Na2SO4 transferred Fe3PO7 from the iron oxides to nepheline, which upgraded the separation of iron and phosphorus. However, NaCl did not inhibit the reduction of phosphorus in the iron minerals. In addition, Na2CO3 strengthened the reduction of iron oxides. However, a small amount of wustite failed to be reduced to metallic iron with the addition of NaCl, and troilite and wustite formed hindered the reduction of iron minerals after adding Na2SO4.

Effect of geological origin of apatite on reverse flotation separation of phosphate ores using phosphoric acid as depressant

Apatites of different geological origins exhibit different floatabilities under the direct flotation process. However, the floatability of apatite from different geological origins under reverse flotation, especially in acidic environments, has not yet been reported. In this study, sedimentary (SD), igneous (IG), and sedimentary metamorphic (SM) apatite minerals are chosen as raw materials to investigate the relationship between the geological origin and flotation behavior of apatite in acidic environments, by means of flotation tests and a series of analyses. The geological origin of apatite affects its solubility in an acidic environment. Furthermore, compared to apatite from IG and SM deposits, there is more substitution of PO43− by CO32– on apatite from SD deposits, which accelerates the dissolution of Ca2+ and Mg2+ ions from its surface, thereby causing fewer active sites to remain on its surface. Under the same phosphoric acid dosage, the floatability of the three apatite follows: IG > SM > SD.

Monitoring of Groundwater Quality With Cokriging of Geochemical and Geoelectrical Measurements

Abstract The study presents the possibility of using geostatistical methods for monitoring groundwater quality. Poland is one of the largest copper producers in the world. However, the extraction and production of copper requires constant care for the natural environment. Reservoir Żelazny Most which is situated in South – Western Poland was designed to store flotation tailings out of nearby copper mines. It is one of the biggest industrial dumps in the world. The reservoir stores huge amounts of tailings and industrial water. Water migrating from dump to groundwater could be a potential source of contamination with chlorides, sulphates, heavy metals, and other hazardous substances used in ore separation process in the copper mining industry, like detergent and phenols. Monitoring system around Żelazny Most dump, which was designed to track harmful substances concentrations in groundwater, contains measuring wells and piezometers. They are used to collect groundwater samples for chemical analyses. The idea of the study was to integrate information provided by chemical analyses and geoelectrical measurements by cokriging method, utilizing correlation between electrical resistance of the soil solution and total dissolved solids concentration in groundwater. This enabled to obtain spatial distribution of total dissolved solids concentrations in groundwater at the part of eastern foreground of Żelazny Most dump.

Dynamic behavior and separation prediction of magnetic ore bulks in dry medium-intensity magnetic separator

Dry medium-intensity magnetic separator (DMIMS) plays a vital role in enhancing the separation of low-grade raw magnetite ore. A good understanding of the dynamic separation process of DMIMS would further boost its economic competitiveness in minerals processing and engineering. Herein, this study analyzed the basic structure and simulated the dynamic separation process of DMIMS in detail using CT4050 magnetic separator as an example. Forces (e.g., magnetic force, magnetic particle-particle attraction and gravity) acting on magnetic ore bulks in multi-physical fields have been systematically investigated to deepen the understanding for the dynamic behavior of magnetic ore bulks based on elaborate experiments and dynamic simulation using the finite element method (FEM). Results show that the realistic movement trajectory of isolated magnetic ore bulks can be well predicated using dynamics simulation. Force analysis demonstrates that the size significantly affects the forces acting on magnetic ore bulks. The magnetic permeability of bulks not only determines their movement trajectory just as the speed of conveyor belt does, but also is vital in improving the separation efficiency. Whereas, the shape, size and rotation angle of bulks demonstrate negligible influence on their movement trajectory and separation efficiency. This study could provide theoretical insights for optimizing the magnetic separation process and designing high-performance DMIMS.

Intensification of the flotation separation of potash ore using ultrasound treatment

The difficulties of beneficiation of the potash ores by flotation is controlled by the structural similarity of the soluble salt minerals such as halite NaCl and sylvite KCl leading to the same surface properties and reactivity of those minerals when cationic reagents are used as collector. In this work, the effect of sonication on the selective flotation and separation contrast between sylvite KCl and halite NaCl in saturated salt solutions was investigated. The flotation experiments were performed on the potash ore samples from the Verkhnekamskoye deposit, Russia, using primary amine as the collector. Different particle sizes (0.5–1 mm, 0.25–0.5 mm, and 0.1–0.25 mm) with similar contents of K (26–29 %) and Na (16.5–18 %) and the same mineralogical compositions were studied. Pulp sonication was performed during the conditioning and/or flotation stages at 30 % solid content in a mechanical flotation machine using an ultrasonic generator at powers from 10 to 75 W at a resonant frequency of 20 kHz. In the absence of the sonication, the maximum recovery of sylvite was obtained for the size fraction of 0.25–0.5 mm (93.99 %) while the sylvite recovery was low for the coarse-grained fraction (0.5–1 mm). The lowest flotation selectivity was observed for the fine-grained ore sample (0.1–0.25 mm). The combined ultrasonic treatment of this sample during conditioning and flotation approximately halved the recovery of NaCl in the potash concentrate (from 17.9 % to 9.9 %) and increased the KCl recovery from 89.9 % to 95.9 %. The addition of a frother increased significantly the sylvite recovery under sonication for coarse size fraction while the effect was less prononoced for the intermediate size fraction. The enhanced flotation selectivity between KCl and NaCl under sonication was attributed to the increased detachment of weak hydrophobic NaCl particles from air bubbles according to the particle size and mode of treatment. The collector desorption from the halite surface unrevealed by the diffuse reflectance infrared spectroscopy was suggested as a factor controlling the selective detachment of low hydrophobic particles under sonication. Therefore, based on our results, a balance must be established between the particle size, collector consumption, ultrasound treatment power, and sonication method (during conditioning with reagents or/and flotation) to optimize the separation between NaCl and KCl.

Froth flotation process and its application

AbstractThe paper is about the froth flotation process and its application. It is a metallurgical process for the extraction of metals in a pure state from their ores: especially for sulfide ores. Froth flotation is one of the steps which is generally performed before roasting and it deals with the surface chemistry of liquids and of the minerals to be separated. This process requires a particular setup to be performed which contains different components. Surfactants play the most important role here. Different types of surfactants are used in different ways and each of them plays a crucial role like, collectors, frothers, froth stabilizers, depressants and activators, pH regulators etc. The sulfide ore flotation process can be studied by both chemical and electrochemical phenomena considering the interfacial energies. A broad application of this process in industrial field is the flotation of iron ores which is of two types: direct and reverse flotation. The later one is again based on two different types as cationic and anionic reverse flotation. In all these processes different types of flotation reagents are used. Another application is separation of malachite and azurite ore using sulfidization flotation.

Research on the transportation and flow characteristics of deep-sea ore transportation equipment

This paper takes the valve-controlled clean water pump ore transportation equipment as the research object, and establishes the mathematical model and finite element model of the ore separator. Based on the calculation method provided by Computational Fluid Dynamics, the numerical simulation and experimental study of the solid-liquid two-phase flow process inside the ore separator is carried out. Furthermore, a single factor analysis method is used to analyze its working performance, separation and conveying efficiency. The change in particle concentration changes the flow characteristics of the internal flow field of the storage tank, increases the number of ore flowing into the separator per unit time, and ultimately affects the separation performance of the ore separator. With the increase of particle concentration, the ore separation efficiency η increases first and then decreases. When the particle concentration is 10%, the slurry separation efficiency is the highest, about 98.93%. With the increase of the particle size, the efficiency of ore particles flowing into the storage tank increases first and then decreases. When the particle size is 20 mm, the value of ξ is higher, reaching more than 92%.

Carbothermic reduction roasting for processing of ferruginous chromite ore using conventional and microwave heating

The present study investigates the recovery of chromite from a low-grade ferruginous ore through the carbothermic magnetization route using conventional and microwave heating sources. The carbothermic magnetization of ore is studied in both a horizontal tube furnace and a microwave oven by varying different process variables. The main objective of the study is to enhance the magnetic susceptibility of iron-bearing gangue minerals to enable the separation in a magnetic field. Alteration of crystalline structure and magnetic property of these minerals enables separation of low-grade ore by using magnetic separation. It is found that low-grade ferruginous chromite ore can be upgraded by reduction roasting, and 61.2% Cr2O3 was recovered with a chromium-to-iron ratio of 1.93 from a feed chromium-to-iron ratio of 1.01. The optimum result is achieved at a roasting temperature of 800 °C, with a roasting time of 60 min and a reductant dosage of 7.5%. Similarly, under microwave radiation, the chromium-to-iron ratio was upgraded to 1.81 with a recovery of 22%Cr2O3. The optimum result achieved under microwave radiation is at a microwave power of 900 W and exposure time of 7.5 min, with a reductant dosage of 10%. The findings of these two processing routes are discussed through characterization tools.

Efficient separation of zinc from zinc containing copper sulfide concentrate by chemical leaching

As the most abundant copper containing resource and zinc containing resource, chalcopyrite and sphalerite/marmatite commonly coexist as Cu-Zn mixed ores in deposits. However, it is difficult to completely separate sphalerite and chalcopyrite by flotation, thus resulting in the existence of zinc impurity in copper concentrate. Sphalerite/marmatite existed in copper sulfide concentrate as impurity may lead to severe damage of the smelting equipment, and cause the waste of copper and Zn resources, it will also decrease of the sale price of copper concentrates. Therefore, the deep separation of zinc from zinc bearing copper sulfide concentrate is of great significance. In this work, selective chemical leaching was developed to efficiently remove zinc from zinc containing copper sulfide concentrate. Under the optimal condition (i.e., sulfuric acid concentration exceed 100 g/L, temperature of 80 °C, pulp density of 10%, leaching time of 48 h), over 85% Zn was extracted into the leaching solution together with only about 10% Cu and Fe, according to the leaching experiment. Leaching slurry had good solid-liquid separation characteristics, and zinc can be further effectively recovered from the leaching solution. According to X-ray diffraction (XRD) and scanning electron microscope/energy dispersive spectrometer (SEM/EDS) analysis, chalcopyrite was the main mineralogical phase in the residues, which can be regarded as high quality copper concentrate for metallurgy. Accordingly, a new process for deep and efficient separation of Cu-Zn mixed ores has been proposed.

Improving the technology of gold ore X-ray radiometric separation

Introduction. Gold ore pre-concentration is an urgent issue that can efficiently be solved by the technology of X-ray radiometric separation (XRS). Quarts and quarts-sulfide gold ore XRS is based on the methods of indirect sorting by gold accompanying chemical elements or genetic associate minerals laying the foundation for the creation of separation characteristics for these ores. Additional separation characteristics are required for efficient gold-quartz and gold-quartz-sulfide ore sorting; Irgiredmet Research Institute works on these characteristics search and development. Research methodology. Optimal ore separation characteristics for each specific deposit are chosen after studying and analyzing the spectral information acquired at XRF separators when detecting secondary characteristic radiation from each specific deposit ore samples. The recent modernization of XRF separators significantly enhanced the technological capabilities of XRS concerning intensive search and study of new separation characteristics for gold ore. It has been established that most ores can be efficiently sorted by three characteristics. Research results. A new method of gold ore XRS has been developed which consists of simultaneously applying three, two, or one decision criterion of a lump separation depending on the type, geologicalmineralogical properties, and material composition of the processed ore

Separation of wolframite ore by froth flotation using a novel “crab” structure sebacoyl hydroxamic acid collector without Pb(NO3)2 activation

In this study, a new hydroxamic-acid molecule - sebacoyl hydroxamic acid (SHA) was synthesized and characterized. It was the first time that SHA with dual hydroxamic acid groups of “crab” structure was used as a collector for wolframite flotation, and its collecting ability was compared with the traditional collector benzohydroxamic acid (BAH) in the presence or absence of lead ions. In micro-flotation experiments, the wolframite recovery using 4 × 10−4 mol/L SHA collector alone was 30% higher than that using 4 × 10−4 mol/L BHA collector and 1 × 10−4 mol/L Pb(NO3)2 activator. The results of bench-scale flotation experiments showed that the WO3 recovery of wolframite concentrate with 180 g/t SHA was 10.05% higher than that with 360 g/t BHA and 300 g/t Pb(NO3)2. Therefore, using SHA collector with “crab” structure for wolframite flotation can not only improve the separation index at a low dosage, but also eliminate the use of Pb(NO3)2.

Recovery of Some Critical Raw Materials from Processing Waste of Feldspar Ore Related to Hydrothermally Altered Granite: Laboratory-Scale Beneficiation

Feldspar for ceramic/glass industries requires sufficiently low content of harmful colourants (Fe-, Ti-, Mn-bearing mineral phases). Hydrothermally altered albite-rich granites are increasingly used as feldspar raw material nowadays; however, they are often marked by increased content of colourants, which must be removed during the processing of feldspar ore. Parallel to the content of colourants, these phases show enrichment in some critical raw materials (CRMs), specifically of Nb, Ta, and Li. In the current study, the laboratory trials focused on the possibility of reprocessing of waste generated during basic magnetic separation of feldspar ore. Major aim of these trials was to search for a processing scheme that would allow for obtaining of mineralogically homogeneous fractions, part of which could be utilised as a source of CRMs. According to the results, combination of gravity, magnetic and heavy liquid separation is highly effective in obtaining of desirable concentrates. Feldspar ore processing waste thus presents potential source of CRMs; however, semi-industrial and full-scale trial must follow in order to prove the economic and environmental suitability of the suggested processing scheme.

Characterizing magnesite heavy-media separation screenings as promising technogenic raw materials

Introduction. This article discusses the possibility of using technogenic raw materials for the production of magnesia and magnesium oxide. The analysis of domestic industry supply with magnesite and magnesian raw materials is presented. Man-made minerals, such as magnesite screenings, produced in the course of heavy-media separation of ore, are noted to be a promising source of this type of raw material. It has been established that this type of raw material is poorly studied. Research methodology. The applied research methods were substantiated to establish the amount and form of magnesium oxide in the magnesite screenings of the Satka deposit. Results and discussion. A significant amount of both current and accumulated screenings at the site in Satka and their chemical composition allow us to consider them as a promising technogenic raw material for magnesium oxide production. The work has determined the distribution of magnesium oxide by size classes. On the basis of elemental analysis, it was decided to recognize the object under study as a suitable mineral for processing. The thermogravimetric analysis of magnesite screenings made it possible to establish the forms of magnesium oxide in the material. Conclusions. Analysis of the results obtained allows us to assert the possibility of processing the studied technogenic raw materials, but the presence of magnesium oxide in the composition of solid solutions with calcium carbonate predetermines the use of chemical enrichment methods.

Rapid and automated separation of uranium ore concentrates for trace element analysis by inductively coupled plasma – optical emission spectroscopy/triple quadrupole mass spectrometry

The present study documents an automated approach to performing elemental analysis on a large group uranium ore concentrate (UOC) samples. Here, 17 UOC samples, 2 quality control samples, and 26 process blanks were purified sequentially through a single 500 μL Uranium and TEtra Valent Actinides (UTEVA®) column. For each sample, the trace elemental impurities were separated from its dissolved uranium matrix on the UTEVA column and collected for analysis by inductively coupled plasma – optical emission spectroscopy / triple quadrupole mass spectrometry (ICP-OES/TQMS). The UTEVA column was subsequently regenerated prior to separation of the following sample. The column was efficiently regenerated, for each UOC, even after processing ~50 mg of uranium, cumulatively. The validity of the method was established by determining the trace impurities of two quality control uranium reference samples (CRM 124–1 and CUP-2). The current trace element measurements from the 17 UOC samples were compared to previously reported values from an interlaboratory comparison exercise, when available. The methodology employed here produces trace elemental analysis with excellent correlation to the previously reported data for many of the elements / samples, particularly when viewed through the context of existing geochemical comparisons tools (e.g. chondrite normalized variation plots).

Selective passivation behavior of galena surface by sulfuric acid and a novel flotation separation method for copper-lead sulfide ore without collector and inhibitor

Here, we present a novel efficient passivation-separation method for galena and chalcopyrite that includes a novel sulfuric acid selective passivation process for galena and a special flotation process in which conventional inhibitors and collectors are not added. The surface passivation mechanism of galena was characterized by surface contact angle measurements, scanning electron and dispersive spectrometry (SEM-EDS) analysis and X-ray photoelectron spectroscopy (XPS) analysis. The contact angle measurements indicated that sulfuric acid passivation increased the surface hydrophobicity difference between galena and chalcopyrite, which led to the large difference in their floatabilities. The results of the passivation-flotation experiments for the galena-chalcopyrite mixture confirmed that the selective inhibition of galena was realized with this new process, and the floatability of galena was drastically reduced while that of chalcopyrite was slightly promoted; thus, the efficient separation of galena and chalcopyrite was achieved only with the addition of frothers. The SEM-EDS and XPS results revealed that the S element on the galena surface was gradually oxidized from S2− to SO42− during the passivation process, which generated a layer of hydrophilic lead sulfate (PbSO4), while a layer of floatable copper sulfides was formed on the surface of chalcopyrite. In this study, a new highly efficient copper-lead sulfide ore separation method was developed, and the interrelatedmechanism was studied in detail.

Novel insights into the reoxidation of direct reduced iron (DRI) during ball-mill treatment: A combined experimental and computational study

High quality direct reduced iron (DRI) plays a fundamental role in determining the functional properties of high-quality steel. DRI powder with a metallization ratio of 82.82% was obtained by reduction-grinding separation of low-grade iron ore, and iron resource was recycled (recovery ratio: 87.96%). However, a serious reoxidation phenomenon occurs in the grinding system, which is also a common problem in extraction metallurgy based on this process. Therefore, a combined experimental and computational study was executed to investigate the reoxidation. Phase evolution analysis shows that Fe0 in bulk iron particles mainly shift to Fe2+ during the grinding process, while Fe3+ are the main valence state on the nano-surface, indicating the reoxidation occurs via diffusion from the nano-surface to the interior. The cleavage surfaces (Fe100/110) occurred in grinding process are more easily to form FeO ionic bonds with O2, especially when surface defects appear, as calculated by DFT. Further, the deeper iron atoms are more exposed after the defected iron surfaces combine with O2, greatly increasing contact opportunities of FeO2. Therefore, the reduction time should be appropriately extended to decrease the surface defects of new iron, and other wet ball mills should be selected for the treatment of DRI produced by this process.