Copper Flotation Research Articles

Selectivity in the flotation of copper with xanthate over other ions present in wastewater: An experimental and computational study

In this work, molecular modeling simulations are used to study the flotation process of copper, cadmium and zinc ions present in wastewater, acid mine drainage and others, with xanthate collector. Simulations were conducted by DFT technique, with M06 functional at 6-31G(d,p)/LanL2DZ level. Characterizations of the molecular and electronic structures of the complexes formed applying NPA, AIM and CLPO analysis of the coordination bonds show the kind of main interactions between metals and the ligand. Results confirm the experimental evidence and show the ability of this technique to study this process. The interaction energy of the studied complexes is −56,39 kcal/mol for Cu, −25,86 kcal/mol for Cd and −7,29 kcal/mol for Zn complex. It was found that xanthate binds to copper over zinc and cadmium elements. Experimental results show that for copper, cadmium and zinc, the flotation effectiveness are 94,68%; 67,18% and 36,92% respectively.

Chalcopyrite Floatability in Flotation Plant of the Rudnik Mine

Part of large-scale industrial test results of milling fineness influence on lead, copper and zinc minerals flotation results in the Rudnik flotation plant are shown in this paper. Based on industrial research it has been concluded that one-stage milling and two-stage classification of complex Pb-Zn-Cu ore leads to so-called “differential milling”. Namely, galena has much faster comminution than other minerals present in ore due to galena softness. This occurrence leads to galena converting into small particles size fractions which have low flotation rate and, at the same time, copper and zinc minerals stay “unliberated” in coarse particle size fractions (minerals are not free of mutual bonds). In this paper, recorded copper minerals flotation products results are shown, including lead underflow (copper flotation input), copper concentrate and copper underflow, in function of particle size; particle size distribution, minerals and metals distribution in function of particle size were determined; obtained research results confirmed “differential milling” assumption, as well as severe floatability difference between chalcopyrite of a different particle size.

Determination of the Relationship Between Foam Images with % Copper Grade in Copper Flotation Process by Image Analysis Method

Bu çalışmada, Siirt Madenköy flotasyon tesisinden temin edilen bakır cevherinin laboratuvar ölçekli flotasyonu esnasında elde edilen köpük görüntüleri ile bakır zenginleştirme tenörü arasındaki korelasyon belirlenmiştir. Sadece hava akış hızı; 2 ile 8 l/dk arasında debimetre yardımı ile değiştirilmiş, diğer tüm flotasyon parametreleri tesis ile aynı tutulmuştur. Video kamera kullanılarak elde edilen köpük görüntüleri, MATLAB Havza Dönüşümü (MATLAB Watershed Transform) metoduyla işlenmiş ve hava kabarcıkları tanımlanmıştır. Kabarcık şekil ve büyüklük verileri, köpük görüntülerindeki kabarcık vadi sınırlarının tespiti ve bu sınırlarla görüntünün bölümlenmesi yoluyla elde edilmiştir. Bu çalışmada gerçekleştirilen 3 farklı flotasyon deney seti verileri kullanılarak flotasyon prosesinin otomasyonunda kullanılabilecek görüntü işleme tabanlı bulanık mantık çıkarım sistemi tasarımı yapılmıştır. Ölçülen ve hesaplanan bakır zenginleştirme tenörü arasındaki korelasyon katsayısı r = 0,96 olarak hesaplanmıştır.

Failures and a concept of corrosion protection system for spiral classifiers at KGHM Polska Miedź S.A. Ore Concentration Plant

The Ore Concentration Plant, where the process of flotation is carried out as well as the final production of copper concentrate, plays a key role in the entire production line of KGHM Polska Miedź S.A. Majority of operations related to the run-of-mine preparation to copper flotation enrichment are carried out in a water environment. The maintaining of production process continuity requires to pursue minimisation of many production limitations. The corrosive action of the technological medium, being a salted water suspension of ground copper ore, is one of them. The concept of spiral classifiers cathodic protection presented in this paper may become an alternative to the anti-corrosion protection methods of machinery and equipment used now at the KGHM.The obtained results of research indicate a possibility of significant reduction of classifiers corrosion rate at the application of cathodic protection and of a few times extension of the period of spiral classifiers operation, which replacement generates substantial operating costs.

Mechanism of the combined effects of air rate and froth depth on entrainment factor in copper flotation

Mechanism of the combined effects of air rate and froth depth on entrainment factor in copper flotation

Zeta Potential of Pyrite Particles in Concentrated Solutions of Monovalent Seawater Electrolytes and Amyl Xanthate

Charge screening and adsorption capacity of monovalent ions onto pyrite (Py) in aqueous suspensions and the effect of potassium amyl xanthate (PAX) has been studied by measuring the changes in zeta potential (zp) versus pH with streaming potential. PAX addition in the absence of salts leads to an increase in |zp| suggesting dissolution of the surface ferric hydroxides and recovery of bare Py, corroborating existing theories. In the presence of salt, addition of PAX at pH > 6, for which hydroxides interference in not expected, has little effect over the zp, except when Li is present. The water network around the polar head of PAX is expected to be similar to that of hydrated Li+ facilitating the linkage between them and, thus, the formation of Li-mediated Py–PAX bridges. We speculate that these bridges lead to a xanthate shield around anionic sites on Py, decreasing |zp|. An increased PAX dose amplifies the effect of Li as a Py activator but only at low salt. At high salt concentrations, >0.01 M, PAX molecules do not find room to percolate to the surface of Py. Results for monovalent cations should improve our understanding of copper flotation processes in the presence of Py in saltwater.

A technique to determine ore variability in a sulphide ore

Ore variability is a big challenge for mineral processing operations, especially in the flotation of complex polymetallic sulphide ores. Processing and blending strategies are determined mostly based on chemical and mineralogical characterization. However, surface characteristics of sulphide minerals is an equally important parameter affecting flotation performance. Changes in surface characteristics of sulphide minerals are usually studied at laboratory scale by using sophisticated equipment, such as ToFSIMs, XPS, etc. In this paper, use of Oxidation Index methodology based on the EDTA extraction technique was evaluated for determination of the presence of secondary copper minerals and surface oxidation of sulphide minerals using a low grade VMS ore deposit from Turkey. These two surface chemistry parameters are known to influence flotation performance significantly, particularly in the copper flotation stage. Therefore, ore variability across the entire ore deposit was evaluated using the relationship between Oxidation Index and flotation performance. The results showed that this methodology can potentially be used as a practical and cost effective method for mapping an ore body regarding variations in surface chemistry of sulphide minerals, prediction of flotation recoveries and selectivity.

The role of sodium metabisulphite in depressing pyrite in chalcopyrite flotation using saline water

In response to the high pyrite recovery in copper flotation using seawater, this study investigated the role of sodium metabisulphite (MBS), a widely used pyrite depressant, in depressing the flotation of copper-activated pyrite to identify a solution to maximising pyrite rejection. It started with chalcopyrite flotation against pyrite with MBS added in the mill before grinding and in the conditioning cell before flotation. The surface properties of pyrite exposed to different reagent schemes were investigated by X-ray photoelectron spectroscopy (XPS) analysis. The reactions on pyrite surface responsible for different flotation results were then investigated by cyclic voltammogram (CV) measurements and discussed in terms of a radical chain mechanism involving the redox cycling of Cu(I/II) induced by sulphite species. It was found that the addition of MBS during the conditioning stage was more efficient in depressing the flotation of copper-activated pyrite. This is because the combination of sulphite ions and oxygen may form a strongly oxidising radical SO5·- which can oxidise Cu(I)S, the copper activation product on pyrite surface, to form hydrophilic Cu(OH)2/CuSO4. The addition of MBS at low dosages in the mill depressed pyrite flotation to a less extent due to the less oxygen available, while its depression effect was even weakened at high dosages due to the consumption of dissolved oxygen and a strongly reducing environment which favoured copper activation on pyrite surface.

Flotation behavior of enargite in the process of flotation using seawater

The presence of enargite (Cu3AsS4) in porphyry copper deposits is an important matter as this mineral shows good flotability in the presence of the thiol collectors used in the flotation copper sulfides thus contaminating the final concentrate. Besides a relevant problem in Chilean mining is the scarcity of water resources so the use of seawater has become a feasible solution. The flotation behavior of copper sulfides and molybdenite in seawater was previously studied but there are no systematic studies related to the flotation of enargite using seawater. The objective of this work is to study the behavior of enargite in the process of flotation using seawater and to compare the flotation of enargite and chalcopyrite in this aqueous medium. The results indicate that the recovery of enargite is strongly depressed at pH > 9 in the process of flotation using seawater, behavior that can be explained in the first place by the adhesion of the hydrolysis products of magnesium on the surfaces of the enargite particles. The analyses of the Pourbaix diagrams for the As-Ca and As-Mg systems also suggest that the enargite depression in seawater observed at pH > 9 can not only be related to the adsorption of hydroxo complexes of magnesium and calcium, but also to the interaction of these metals with oxidized arsenic species such as arsenate and arsenite. As these compounds are hydrophilic in nature they reduce enargite recovery. Pre-treatment of seawater before flotation to remove most of the calcium and magnesium present through the precipitation of hydrolyzed complexes of these cations is a suitable way to improve enargite recovery at pH > 9.

Improvement of porphyry copper flotation efficiency with auxiliary collecting agents based on acetylene alcohols

Improvement of porphyry copper flotation efficiency with auxiliary collecting agents based on acetylene alcohols

Assessment of operating performance using cross-domain feature transfer learning

Assessment of operating performance evaluates optimal degree for processes under normal conditions. Maintaining in good operating performance indicates high benefit of the production. To assess the performance for a newly built process with a small number of historical data, a cross-domain feature transfer learning (CDFTL) method is proposed in this research. The assumption that the data from the source and target domains should be independent and identically distributed is no longer necessary. The common and specific features are both utilized to guarantee the assessment precision and model generalization ability. Finally, the proposed method is applied to a copper flotation process.

Using Partial Desalination Treatment To Improve the Recovery of Copper and Molybdenum Minerals in the Chilean Mining Industry

Limited water resources and greenhouse gas emissions from fossil fuels used in electricity production are problems experienced in Chile. To address water shortages, many copper mining companies have started to use seawater or desalinated water in their operations. However, seawater exerts a negative impact on the mineral processing operation. It reduces the recovery of copper and molybdenum minerals in the flotation of copper–molybdenum sulfide ores due to the presence of calcium and magnesium ions. This study aims to propose a partial desalination treatment for calcium and magnesium species removal to improve the recovery of valuable minerals in the flotation of copper–molybdenum sulfide ores. The proposed method uses carbon dioxide gas and sodium hydroxide to promote the removal of calcium and magnesium ions from seawater. As a result, the partial desalination treatment can remove 60.5% of calcium and 98.3% of magnesium species. In addition, it helped in reaching a high recovery of molybdenum (81.1%) an...

Characterization and geostatistical modelling of contaminants and added value metals from an abandoned Cu–Au tailing dam in Taltal (Chile)

The city of Taltal, located on the north coast of Chile, with central coordinates S 25° 23 ‘52 “and W 70° 28′ 35″, is important for small-scale mining. Depending on the price of metals, the population moves between mining and fishing.A pair of tailings dams called S1 and S2 belonging to a private company, currently abandoned, were studied. This small company was created only to process minerals that were contributed by mines located approximately 100–120 km south of the city. This study was conducted with a complete approach of mineralogical, elementary and geostatistical modelling. The deposits were characterized as copper flotation tailings and mercury - gold amalgams.The goal of this study is to know the existence and abundance of elements that can give added value to these abandoned deposits. As well as the presence of heavy metals.The results obtained agree with this fact, identifying several copper ores (mainly oxides, oxidized and sulphide minerals). Copper has average concentrates of 0.27% in S1, and 0.48% in S2). In addition, it was possible to identify the presence of gold (0.26 ppm S1, 0.53 ppm S2 as averages) and high concentrations of heavy metals (mercury and arsenic) that could potentially be toxic. Rare earths were also identified as value-added elements and with competitive concentrations that will be addressed in subsequent studies.

Modeling and optimization of chemical reagents to improve copper flotation performance using response surface methodology

ABSTRACTIn this paper, the main and interaction effects of chemical reagent (collector and frother) dosages on the copper flotation performance using response surface methodology in design expert software were examined and the optimized dosage of reagents were specified. Then, in order to increase copper grade and recovery at industrial rougher flotation cells of the Miduk copper concentrator, Iran, distribution patterns of chemical reagents in suggested optimum conditions were investigated. A central composite design with three levels and five variables was employed to model and optimize the laboratory batch scale flotation process. The effect of dosages of Z11 (0–10 g/t), Flomin C4132 (14–34 g/t), A3477 (5–15 g/t) as collectors, AF65 (5–15 g/t) and MIBC (4–12 g/t) as frothers was studied. Forty-eight batch rougher flotation experiments (pH 11.5) for Miduk porphyry copper ore consisting of 0.9% Cu were conducted at different conditions using a bench scale Denver flotation cell with 3 L capacity. Second order response functions were generated for both the Cu grade and recovery models, as metallurgical indicators. These model equations were optimized using quadratic programming so as to maximize Cu grade and recovery within the experimental range studied. The main effect of all reagents dosages and the interaction of the Z11-Flomin C4132, Z11-A3477, and A3477-MIBC dosages had a significant impact on both recovery and grade. The optimum reagents dosages were found to be 5 g/t Z11, 34 g/t C4132, 5 g/t A3477, 15 g/t AF65, and 8 g/t MIBC. Maximum recovery of 91.4% and grade 8.13 were achieved under optimal conditions. Additionally, verification experiments at optimum conditions proposed by the models were carried out to specify the validity and adequacy of the predicted models. Based on the industrial rougher circuit tests results, distribution patterns of 75%-0%-25% and 50%-25%-25% were selected as the best distributions of collectors and frothers in mentioned conditions, respectively. The copper recovery and grade improved about 2% and 1.8%, respectively, via the use of optimized stage addition of reagents.

INTEGRATED APPROACH TO NEUTRALIZATION OF WASTEWATER CONTAINING COPPER IONS AND EDTA LIGAND

An analysis of electrochemical degradation of organic compounds, in particular EDTA is presented. The influence of the nature of the anode and the nature of the oxidizing agent on the degradation of organic compounds is showed. Anode materials are classified based on their oxidizing power in an acidic environment. It is shown that direct oxidation of EDTA effectively occurs on the anodes Ti/PbO2 and Ti/SnO2. In the presence of NaCl EDTA is effectively oxidized on the anodes Ti/RuO2-TiO2 by the formation of hypochlorite. Examples of destruction of EDTA under the influence of ultraviolet radiation are given. Degradation products (nitro acetic acid, amino diacetic acid) form CO2, H2O, NO3-ions at full decomposition. It is noted that the neutralization of wastewater containing copper and EDTA is carried out in two stages: destruction of EDTA and the extraction of copper hydroxide. The extraction of copper ions from the system H2O-Cu2+-EDTA-electrolyte with different ratios of metal-ligand is investigated. The effect of EDTA concentration on the flotation process for extracting copper hydroxide is analyzed. The kinetics of flotation of copper extraction in the presence of two complexing agents - NH3 and EDTA is considered. The presented results allow to assess the degree of extraction of copper from solution copper-EDTA at different coal sorbents and resins. It is shown that the use of anion exchange resin Purolite A500 and anion exchange resin AB-17-8 is effective when the copper concentration is 25 mg/l. It is established that the sorption process is slow: stationary values are set for several hours. The degree of extraction of EDTA reaches 30-40%. When the ratio of copper-EDTA 1:1.0-1.5 it is possible to reach flotation copper extraction up to 80%. Under additional sorption treatment the extraction degree reaches to 99%. It is shown that the use of highly dispersed carbon materials (coal powders) allows extracting ligands from wastewater, increasing the efficiency of copper hydroxides electroflotation.

Removal of the residual xanthate from flotation plant tailings using bentonite modified by magnetic nano-particles

The residual organic reagents (including xanthates) in the flotation tailings can cause environmental issues during their disposal, besides their deleterious influence on the flotation performance during recycling. In this study, the adsorption characteristics of bentonite modified with copper and manganese ferrite nanoparticles (BeCuFe2O4, BeMnFe2O4) for xanthate removal from the synthetic and real solutions was studied. The characterization studies by XRF, XRD, BET, SEM, EDX, VSM and FTIR techniques confirmed the formation of magnetic nanoparticles. The adsorption capacity of BeCuFe2O4 was found to be higher than BeMnFe2O4 and at optimum conditions (adsorbent dosage: 4 mg/mL; xanthate concentration: 1000 mg/L; pH = 9.2; time = 40 min) more than 94% of the residual xanthate was removed by this adsorbent. The kinetic studies showed that rate of xanthate adsorption on both adsorbents followed the pseudo-second order model. The intraparticle diffusion was not the only rate-limiting step of the adsorption process. The equilibrium isotherms were best fitted to the Langmuir model. This suggests monolayer adsorption of xanthate on homogenous sites of the adsorbents. The thermodynamic studies revealed that the adsorption process was spontaneous, endothermic and entropy-driven. The synthesized adsorbents were capable of completely removing xanthate from the actual samples taken from the tailings of a copper flotation plant (Qaleh-Zari, Iran).

Effects of Collectors and Frothers on Copper and Molybdenum Coarse Particle Recoveries—A Statistical Approach

Typically, coarse dense mineral particles greater than 150 μm are difficult to float, and the recovery decreases progressively. Various physical parameters can be manipulated in an attempt to increase the recovery. These physical parameters are the following: liberation, turbulence in the flotation cell, pH, collector, frother type and dosage. The testwork discussed in this paper was performed for a copper-molybdenum operation that is experiencing coarse particle (>150 μm) losses in the tails. This operation uses Diesel No. 2 fuel and sodium ethyl xanthate for molybdenum and copper flotation, respectively and X-133 frother. In an attempt to increase coarse particle recovery, stronger collectors (potassium amyl xanthate, Aero 249 and Aero 3501) and frothers (FrothPro 618, FrothPro 630 and FrothPro 706) were used. The analysis was performed using the Analysis of Variance (ANOVA) approach. The conditions required by the ANOVA method were met. The results showed that the collector potassium amyl xanthate (PAX) with frothers X-133 and FrothPro 630 resulted in approximately 3% increase in copper rougher recovery relative to the baseline (sodium ethyl xanthate and X-133). The collectors and frothers did not have a significant effect on molybdenum recovery within the dosage limits investigated.

Interactive Effect of Copper and Its Mineral Collectors on Soil Microbial Activity—A Microcalorimetric Analysis

Discharge of metals and their mineral flotation collectors into the soil environment causes severe ecological and health impacts, which is still not fully understood. This is of great concern, particularly with regards to their effect on the soil microorganisms whose functions determine not only the soil quality and function but also influence the air and water quality. This study aimed to analyze and compare, microcalorimetrically, the single chemical toxic effect with the combined effect of copper (Cu) and two of its main flotation collectors, potassium amyl xanthate (PAX) and sodium isoamyl xanthate (SIAX), on soil microbial community. All chemicals, individually and as a binary mixture of copper and each of its flotation collectors, exhibited a significant dose-effect relationship, and the highest and lowest microbial activity inhibition being associated with SIAX and Cu, respectively (e.g. IC 50 of 447.5, 158.3 and 83.9 μg·g−1 soil for copper, PAX and SIAX, respectively). For all cases, the microbial activity was more affected by the mixture than by the individual mixture components. Increasing the xanthates dose (from 25 to 100 μg·g−1 soil) in the mixture with a copper dose of 200 μg·g−1 soil led to the increase of the microbial activity inhibition rate, from 23.08 % to 53.85% in case of PAX and from 26.92% to 57.69% in case of SIAX). Similarly, the toxicity level of the mixture of equitoxic components doses increased with the increased mixture doses. Since the observed activity level can be attributed to the surviving microbes, capable of adapting to both chemical and their mixture, a genetically based analysis should be conducted to allow identifying and characterizing the potentially resistant strains that can be useful for the remediation of the pollution by copper and xanthates and for the sustainability of copper mining and flotation, and for all soil, water, and air quality and function interest.

Clustering of Copper Flotation Process Based on the AP-GMM Algorithm

The clustering of copper flotation process has a significant impact on the performance of operation adjustment. Nowadays, due to the complexity of the copper flotation process, the adjustment of operational variables, which are controlled by operators, is often not regulated properly in time. Therefore, it is necessary to obtain a clustering strategy for the copper flotation process to guide the operators by taking prompt and effective adjustment strategies. Due to the uncertainty of clustering itself, the number of categories and their respective probabilities are needed. Based on affinity propagation (AP) clustering algorithm and gaussian mixture model (GMM), a clustering algorithm is proposed in this paper, which is referred to as AP-GMM. It can get the optimal number of categories and their respective probabilities without giving the number of categories in advance. On this basis, a new category matching theory is constructed. Inspired by rewards and punishments in reinforcement learning, a penalty function is investigated to verify the optimum number of condition categories for copper flotation process. Finally, experiments show the effectiveness and feasibility of the proposed method.

Flotacijska ispitivanja majdanpečke rude bakra u cilju poboljšanja iskorišćenja bakra i kvaliteta koncentrata primenom različitih kolektora

This paper presents the results of mineralogical and flotation studies on the copper ore from the deposit North Revir in the Copper Mine Majdanpek, using different collectors. XRD and ore mineralogical analysis showed that the most common minerals are pyrite and chalcopyrite. Chemical analysis confirm that it is a complex low-grade copper ore with average copper content of 0,273%. The content of precious metals (Au and Ag) was 0.2 g/t and 1.2 g/t, respectively. The main aim of flotation studies have been the effect of collector type on the recovery and concentrate grade in the copper flotation process. Various collectors and combinations of them were used in the rough flotation tests of copper ore. The copper recovery was in the range from 79.43% (test no. 4) to 84.96% (test no. 7). The best flotation results were obtained with mixture collectors of sodium isopropyl xanthate (Z11), dialkyl dithiophosphinates (Aerophine 3404) and SKIK BZ 2000. The collector's dosages of 20 g/t Z11, 8 g/t AP3404 and 8 g/t SKIK BZ 2000 produced the copper recovery (84.96 %) with copper concentrate grade of 1.52% .