Effect Of Pyrite Research Articles

Flotation of Copper Ores with High Cu/Zn Ratio: Effects of Pyrite on Cu/Zn Separation and an Efficient Method to Enhance Sphalerite Depression

Porphyry copper deposits are important sources of copper and typically processed by flotation to produce copper concentrates. As mining areas become deeper, the amounts of impurities, such as sphalerite, can be increased in copper ores, so the appropriate depression of sphalerite floatability should be achieved to obtain saleable copper concentrates. In this study, the flotation behaviors of chalcopyrite and sphalerite in model samples mimicking copper ores with high Cu/Zn ratios (i.e., the ratio of chalcopyrite/sphalerite = 13:1) were investigated with zinc sulfate as a depressant for sphalerite. In addition, the effect of pyrite—a major gangue mineral in copper ores—on the depression of sphalerite floatability with zinc sulfate was examined. When sphalerite and chalcopyrite coexisted, the floatability of the former was effectively depressed by zinc sulfate (Zn recovery: <12%), whereas the presence of pyrite promoted the release of Cu2+ due to the galvanic interaction with chalcopyrite, which resulted in the elimination of the effectiveness of zinc sulfate in depressing sphalerite floatability (Zn recovery: >90%). Despite the presence of much higher amounts of chalcopyrite and pyrite than sphalerite, the application of nitrogen (N2) gas limiting the galvanic interaction between pyrite and chalcopyrite by reducing the dissolved oxygen (DO) concentration in the system effectively depressed the floatability of sphalerite (Zn recovery: <30%).

Unraveling the dissociation mechanism of gold in carbonaceous gold ore during vacuum roasting pretreatment: Effect of pyrite

Carbonaceous refractory gold ore has been an important gold ore resource for the sustainable development of the gold industry. Solving the harmful effects of mineral-locking is the first step to increase the gold leaching rate. This study employed vacuum roasting technology in the pretreatment of carbonaceous gold ore. The dissociation efficiency and mechanism of gold in carbonaceous gold ore was investigated using a Mineral Liberation Analyser, thermogravimetric analysis, scanning electron microscopy, and X-ray diffraction analysis. The results showed that the effect of gold-locking could be effectively solved through the thermal decomposition of pyrite during vacuum roasting pretreatment. After vacuum roasting, the content of exposed and semi-exposed gold increased from 43.81% to 78.34%, and 72.37% of the gold locked by pyrite was dissociated. Pyrite was continuously desulfurized and converted into low-sulfur pyrrhotite during vacuum roasting, and desulfurization at 400–700 °C was the cause of mass loss and phase transformation of pyrite. The phase transformation of pyrite followed the change pyrite → monoclinic and hexagonal pyrrhotite → hexagonal pyrrhotite → troilite. At 600–700 °C, rapid desulfurization produced a well-developed pore structure of the pyrite particles, which loosened the connection between gold and pyrite. Above 700 °C, the aggregation of pyrrhotite particles by slow desulfurization improved separation of gold and pyrrhotite. Gold locked by pyrite in the carbonaceous gold ore was dissociated effectively under the combined action of the two stages. The high content of exposed and semi-exposed gold provided necessary conditions for the improvement of gold leaching rate in the later leaching process.

Effect of Pyrite on the Leaching Kinetics of Pitchblende in the Process of Acid In Situ Leaching of Uranium

In the process of acid in situ leaching of sandstone uranium ore, pyrite, which is a common associated mineral of pitchblende, would inevitably participate in the reaction. Therefore, it is important to study the influence of pyrite on the leaching kinetics of pitchblende. In this study, we compared the difference leaching rates of pitchblende in the systems of sulfuric acid–hydrogen peroxide, sulfuric acid–hydrogen peroxide–pyrite and sulfuric acid–pyrite and studied the influence of temperature and pyrite quantity on the leaching rate of pitchblende. The results show that the leaching process of pitchblende follows the shrinking particle model controlled by a chemical reaction, and the apparent activation energy Ea of the leaching reaction is (3.74 ± 0.40) × 10 kJ/mol. Pyrite itself cannot promote the dissolution of pitchblende; however, it can promote the leaching of pitchblende in the presence of an oxidizer. Increasing the quantity of pyrite in a certain range can increase the leaching rate of pitchblende, and the reaction order of pyrite is 0.36.

Effect of Pyrite in Water Saturation Evaluation of Clay-Rich Carbonate

In hydrocarbon reservoirs, log analysis and core measurements provide the fundament for water and hydrocarbon saturation evaluation. In mixed mineral formations containing clay and metallic minerals, the electrical resistivity logging tools used for water saturation calculations are significantly affected due to the conductive nature of these minerals, which could result in an inaccurate saturation profile. In this study, we extend Archie’s equation for water saturation calculation in the Lower Cretaceous marly chalk formations in the Danish North Sea. Using Hashin-Shtrikman bounds, we investigate the phase mixing in the formation, providing a consistent and practical method for saturation evaluation in a mixed mineral heterogeneous formation containing conductive minerals.

The use of pyrite to control redox potential to enhance chalcopyrite bioleaching in the presence of Leptospirillum ferriphilum

Redox potential (ORP) was proved to be a key factor in promoting chalcopyrite (CuFeS2) bioleaching. Though there are some methods for maintaining ORP reported previously, little attention has been given to control it via pyrite. In this work, chalcopyrite bioleaching was investigated in the presence of Leptospirillum ferriphilum (L. ferriphilum) with various amounts of pyrite addition. Bioleaching results showed that the addition of pyrite extremely enhanced the dissolution of chalcopyrite, especially when the mass ratio of pyrite and chalcopyrite was 3:1. In this case, ORP was well maintained at an appropriate range (350–370 mV vs. Ag/AgCl) for 25 days. The results of electrochemical tests indicated that the addition of pyrite did not change the electrochemical dissolution mechanism of chalcopyrite. Thus, the effect of pyrite was mainly a redox potential controlling process, and the reduction of chalcopyrite to secondary copper-iron species like chalcocite (Cu2S) was promoted in the optimum range. Eventually, a high copper extraction (70%) was obtained as a result of the rapid dissolution of formed chalcocite. Based on all the obtained results, a model for illustrating the ORP control of pyrite during chalcopyrite bioleaching in the presence of L. ferriphilum was proposed.

Recovery of gold from refractory gold ores: Effect of pyrite on the stability of the thiourea leaching system

The extraction of gold from refractory gold ores (RGOs) without side reactions is an extremely promising endeavor. However, most RGOs contain large amounts of sulfide, such as pyrite. Thus, investigation of the influence of sulfide on the gold leaching process is important to maximize the utilization of RGOs. In this work, the effects of pyrite on the stability of the thiourea system were systematically investigated under different conditions. Results showed that the decomposition rate of thiourea was accelerated sharply in the presence of pyrite. The effect of pyrite on gold recovery in thiourea leaching systems was then confirmed via a series of experiments. The decomposition efficiency of thiourea decreased by 40% and the recovery efficiency of gold increased by 56% after the removal of sulfide by roasting. Under optimal conditions, the efficiency of the gold recovery system increased to 83.69% and only 57.92% of thiourea decomposition was observed. The high consumption of thiourea by the leaching system may be attributed to not only adsorption by mineral particles but also catalytic decomposition by some impurities in the ores, such as pyrite and soluble ferric oxide.

Kinetics and mechanism of arsenopyrite leaching in nitric acid solutions in the presence of pyrite and Fe(III) ions

The main sulphide minerals that serve as gold carriers in low-grade raw materials are pyrite and arsenopyrite. Traditional methods of processing such refractory raw materials rely on high-pressure or pyrometallurgical oxidisation, which destroys the crystal lattice of sulphides and releases gold particles. An alternative method of oxidation is leaching with nitric acid. The study examined the kinetics and oxidation mechanism of the natural mineral arsenopyrite in nitric acid media, along with the effect of pyrite on the kinetic characteristics of dissolution. Using the shrinking core model (SCM), it was shown that during the first 5 min of the process, the kinetic of the reaction is controlled by the chemical reaction. Further in the course of the process, the mode changes, which is confirmed by the new shrinking core model. During the period from 5 to 60 min the model was fitted according to diffusion through a product layer and interfacial transfer. The addition of Fe(III) ions and an increase in the concentration of nitric acid have a similar effect on the nitric acid leaching of arsenopyrite, which is associated with an increase in the oxidation potential of the system. The influence of pyrite on the leaching of arsenopyrite is probably associated with its catalytic action in the early stage of the process, which is due to the role of an alternative surface for the reduction of nitrate ions in electrochemical contact with arsenopyrite. The difference in the mechanisms of arsenopyrite oxidation in the presence of Fe(III) ions and pyrite was confirmed by the SEM-EDX analysis.

Effect of Phosphate, Sulfate, Arsenate, and Pyrite on Surface Transformations and Chemical Retention of Gold Nanoparticles (Au-NPs) in Partially Saturated Soil Columns.

The understanding of engineered nanoparticle (ENP) fate and transport in soil-water environments is important for the evaluation of potential risks of ENPs to the ecosystem and human health. The effects of pyrite grains and three types of oxyanions-sulfate, phosphate, and arsenate-on the retention of citrate-coated gold nanoparticles (citrate-Au-NPs) were studied in partially saturated soil column experiments. The mobility of Au-NP was found to be in the order: Au-NP-sulfide (originating from pyrite) > Au-NP-sulfate > citrate-Au-NP > Au-NP-arsenate > Au-NP-phosphate. Chemical retention mechanisms, including hydrogen bonding and calcium bridging, are proposed and discussed. The retention of Au-NPs in soil columns increases with the increased ability of transformed Au-NP surfaces to create strong hydrogen bonding through adsorbed oxyanions with soil surfaces. Oxyanions were also found to reduce aggregation and aggregate size of Au-NPs upon interaction with Ca2+ solution. While the effects of cationic substances on ENP transport and stability have been studied frequently, the results here demonstrate that anionic substances have a substantial effect on Au-NP transport and stability. Furthermore, this study highlights the importance of examining ENPs under environmentally relevant condition, and the significant effect of ENP transformations on their mobility in soils.

Effect of pyrite on the electrochemical behavior of chalcopyrite at different potentials in pH 1.8 H2SO4

Chalcopyrite is the most abundant, but also one of the most refractory, copper sources. One way to enhance chalcopyrite’s electrochemical dissolution is by mixing it with pyrite. To understand how and to what extent pyrite affects chalcopyrite’s electrochemical dissolution at different potentials, the electrochemical behaviors of chalcopyrite, pyrite, and chalcopyrite–pyrite couples in pH 1.8 H2SO4 were studied by potentiodynamic and electrochemical impedance spectroscopy. Potentiodynamic curves showed their different electrochemical reaction states and electrode surface characteristics. From open-circuit potential to 470 mV (vs saturated calomel electrode), chalcopyrite–pyrite was passivated with Cu1− xFe1− yS2 [Formula: see text]; from 470 to 580 mV, trans-passive dissolution occurred, and in the passive region, Cu1− xFe1− yS2 transformed into Cu1− x− zS2; from 580 to 700 mV was an active region; and a pseudo-passive region was formed with CuS when the potential was above 700 mV. The smaller charge transfer resistance and passive resistance, as well as the smaller inductive relaxation, revealed how and to what extent the coupled pyrite accelerated the electrochemical dissolution of chalcopyrite.

Resistivity dispersion in pyrite-bearing shaly sandstones

In pyrite-bearing shaly sandstones, the distortion in the resistivity logging response of formations in high-frequency resistivity logging because of dispersion hinders the calculation of reservoir saturation. To eliminate the effect of resistivity dispersion of pyrite and shale, and to avoid factors, such as mineral composition, content, and distribution in natural cores, we synthesized twelve samples with dispersed pyrite and shale grains at high temperature and pressure (60 MPa and 120 °C). We performed experiments at different water salinities and oil saturations, and different frequency to assess the effect of frequency on the conductivity of pyrite-bearing shaly sandstones. Both the dispersed pyrite and shale grains show dispersion, and the real part of the complex resistivity decreases with increasing frequency. Based on symmetrical effective medium conductivity theory and the experimental data, the effective medium dispersion model for the real part of the complex resistivity for pyrite-bearing shaly sandstones is established considering the effect of pyrite and shale content on resistivity dispersion. Simulations suggest that the predicted resistivity dispersion by the model in pyrite-bearing shaly sandstones for variable frequency, and pyrite and shale content agrees with the experimental results. The proposed model can successfully predict the dispersion of pyrite-bearing shaly sandstones. Finally, the resistivity dispersion correction plot for the conductivity of pyrite and shale grains of 0.062 S/m and 0.031 S/m, respectively, is established based on the frequency applied to various electric logs, and the correction method for the high-frequency resistivity log response is given to obtain the real formation resistivity.

Hydrometallurgical processing of non-concentrated manganese - containing raw material with receiving high-quality products

The production of ferroalloys occupies a leading position in the economy of the Republic of Kazakhstan. With the depletion of rich in the content of the initial manganese raw materials, a problem arose that it was necessary to involve technogenic products, i.e. poor sub-standard ores and wastes produced by ferroalloys. From the point of view of environmental protection of regions producing manganese alloys, the current tasks are: the introduction of new efficient dust collection processes; issues of cleaning of waste gases and sludges; neutralization and utilization of waste. The creation of rational technological schemes for the utilization of dispersed materials that contain the target element of the ferroalloy to be melted is an economically viable and environmentally sound measure for increasing the profitability of production. Sulfuric acid leaching is the main operation of most schemes of hydrometallurgical processing of manganese-containing raw materials. Hydrogen peroxide, metallic iron, pyrite concentrate, sulfur dioxide, sulfite-bisulphite solutions used as the reducing agent. The article presents the results of hydrometallurgical processing of manganese dusts produced by the silicomanganese of the Aksu Ferroalloy Plant. To convert the solution of psilomelane (MnOMnO2) – an oxide compound, in which manganese is represented in silicomanganese dust, the presence of a reducing agent in the sulfuric acid solution, which is used as a pyrite concentrate, is necessary. The effect of pyrite on the reduction of manganese dioxide during leaching with sulfuric acid studied by mathematical planning of the experiment by a probabilistic-deterministic method. The determining factors of the leaching process are: temperature, duration of the process, amount of pyrite added, concentration of sulfuric acid. On the basis of significant equations of partial dependence, a mathematical model for the leaching of manganese dust by sulfuric acid in the presence of pyrite is compiled in the form of a generalized equation: Yрасч = 3,7•10-6(0,9399х1+5,1847)(-13,761х22+62,507х2+23,402)(-0,7429х32+14,143х3+23,4)(-00071х42+1,466х4+18,323). On the basis of the obtained equation, the optimal conditions for manganese leaching into a sulfuric acid solution are selected: temperature 700 °C, duration 3 hours, sulfuric acid concentration 5 %, additive of pyritic concentrate 90 % of the dust weight. The degree of manganese extraction was 95.8 %.

Chargeability of Porous Rocks With or Without Metallic Particles

The chargeability of rocks de nes their ability to reversibly store electrical charges at low frequency (typically below a few kHz). We consider the case of an isotropic mixture of metallic particles embedded into a polarizable porous background composed of mineral grains and pore water. The term metallic is here used in a broad sense involving semiconductors (for instance disseminated pyrite or magnetite), semimetals (e.g., graphite), and metals (copper, steel). The chargeability of such a mixture depends on the chargeability of the background material and the volumetric amount of metallic particles. The chargeability of the background material is in turn salinity dependent and is equal to a universal dimensionless number R = 0.08 (ratio between the normalized chargeability and the surface conductivity) at low salinities. It is given by the ratio of two apparent mobilities, which are actually related to the mobility of the Stern and diffuse layers forming the so-called electrical double layer around the mineral grains. This universal number is saturation and temperature independent. The predictive model for the chargeability of the mixture is compared successfully to variety of experimental and eld data. We show that the polarization of dispersed metallic particles is due to the electrodiffusion of the charge carriers inside these particles. This work can be applied to conventional well-log analysis using the dispersion of the electrical conductivity with the frequency in order to determine the formation properties and accounting for the presence of pyrite in some formations. Our conductivity model appears as an extension of the Waxman and Smits seminal model of shaly sands extending this model to determine the chargeability and the effect of pyrite on both the electrical conductivity and the chargeability.

Improving the Total Organic Carbon Estimation of the Eagle Ford Shale with Density Logs by Considering the Effect of Pyrite

Pyrite is a common mineral with a higher density than most other minerals in the Eagle Ford Shale formation. Hence, if pyrite is not considered in the total organic carbon (TOC) estimation, based on density logs, it may lead to errors. In order to improve the accuracy of the TOC estimation, we propose an updated TOC estimation method that incorporates the concentration of pyrite and organic porosity. More than 15 m of Eagle Ford Shale samples were analyzed using Rock-Eval pyrolysis, X-ray fluorescence (XRF), and X-ray diffraction (XRD). TOC, elemental concentration, and mineralogical data were analyzed for a better understanding of the relationship between the concentration of TOC and pyrite content in the Eagle Ford formation. An updated petrophysical model—including parameters such as organic pores, solid organic matter, inorganic pores, pyrite, and inorganic rock matrix without pyrite—was built using the sample data from the Eagle Ford. The model was compared with Schmoker’s model and validated with the Eagle Ford field data. The results showed that the updated model had a lower root mean square error (RMSE) than Schmoker’s model. Therefore, it could be used in the future estimation of TOC in pyrite-rich formations.

Influence of the Interaction between Sphalerite and Pyrite on the Copper Activation of Sphalerite

In this paper, the effect of pyrite on the activation of sphalerite was investigated by micro-flotation, copper adsorption experiments, X-ray photoelectron spectroscopy (XPS), and electrochemical measurement. The micro-flotation test results showed that the recovery and flotation rate of sphalerite with copper sulphate as activator and butyl xanthate as collector were significantly decreased with the increasing content of pyrite in pulp. Cu2+ adsorption results indicated that the adsorption of Cu2+ on the sphalerite surface were decreased when pyrite was present in the pulp. XPS surface analysis demonstrated that the proportion of Cu+ species increased in the activation products on the sphalerite surface, but the total atomic concentration of Cu atom was decreased. Linear voltammetry measurement suggested that the current density of Cu+ species oxidizing to Cu2+ species was increased when sphalerite was electrically contacted with pyrite, which confirmed the increased proportion of Cu+ species on Cu-activation sphalerite surface when contacting with pyrite. These results indicated that there is not only a competitive adsorption for cupric ions (Cu2+), but the galvanic interaction between sphalerite and pyrite also has a significant influence on the copper activation of sphalerite.

The Influence of Pyrite on Galvanic Assisted Bioleaching of Low Grade Chalcopyrite Ores

The experiment focused on the effect of pyrite on the dissolution of the ore from Saindak copper mine in Pakistan. The MLA results showed that the ore mainly consisted of chalcopyrite, which was associated closely with pyrite. The bioleaching process and galvanic promotion experiments of pyrite on the copper extraction were investigated. The data revealed that copper recovery rate could be up to 97.8% after the bioleaching process by extreme thermophilic acidophilic organisms for 30 days at 65 OC. The temperature and redox potential were the controlled factors to recover copper from the Saindak mineral. The phylogenetic analyses of 16S rRNA gene fragments revealed that organisms related to Metallosphaera cuprina strain Ar-4 and Sulfolobus sp. HB59 were most dominant. Pyrite could accelerate the dissolution of chalcopyrite as one galvanic assistant substance, which would be strengthened by elevating the temperature or in the presence of microorganisms.

Leaching and Kinetic Study on Pressure Oxidation of Chalcopyrite in H2SO4 Solution and the Effect of Pyrite on Chalcopyrite Leaching

The leaching of copper from chalcopyrite in H2SO4 solution under pressure-oxidative conditions and its kinetics were investigated in this study. Leaching variables that affect the rate of copper dissolution from chalcopyrite are agitation speed (300–900 rpm), total pressure (0.8–2.0 MPa), temperature (160–180 °C), and sulfuric acid concentration (0.1–2.0 M). Results showed that dissolution of chalcopyrite increases with increasing agitation speed, total pressure, and temperature, whereas it decreases with the increasing sulfuric acid concentration. Under the optimal conditions, copper extraction of 94.5% was achieved after 90-min leaching, while a dissolution of iron at 4.2% was obtained. The kinetic study showed that the dissolution of chalcopyrite is represented by a shrinking core model with chemical reaction controlling mechanism given as (1 − (1 − α)1/3). The activation energy (E a) for the leaching reaction was calculated to be 42.4 kJ/mol. The reaction order with respect to total pressure was about 8.0, which indicates that total pressure, i.e., oxygen partial pressure, in an autoclave is the most important factor in controlling the dissolution of chalcopyrite in H2SO4 solution under pressure-oxidative leaching conditions. The effect of Fe/Cu mole ratio (1–20 mol/mol, adjusted by addition of pyrite) on chalcopyrite leaching from a copper ore was investigated. The results show that the sulfuric acid produced during pyrite oxidation promotes the chalcopyrite dissolution.

Bioleaching of Different Pyrites and Sphalerite in the Presence of Graphite

ABSTRACTIn this research work the effect of pyrite type and graphite on the pyrite and sphalerite dissolution rate was investigated, using a mixed culture of moderately thermophilic microorganisms. Two samples of: fine granular surface pyrite and crystalline euhedral pyrite were prepared from black shale and copper porphyry deposits, respectively. Results indicated that granular surface pyrite dissolution rate and Fe(III) concentration are significantly higher than those of crystalline euhedral pyrite. As a result, higher Zn extraction improvement was observed in the presence of granular surface pyrite. Addition of graphite to the experiments enhanced the microorganism population in leaching solution and accelerated crystalline euhedral pyrite and sphalerite bioleaching rate. Using graphite in the experiments resulted in catalytic effect of crystalline pyrite and sphalerite, in which, with graphite, the Fe extraction increased from 25.57% to 59.84% and Zn extraction was improved from 22.17% to 53.37%, for 28 days of bioleaching. The catalytic effect of graphite on crystalline euhedral pyrite and also sphalerite bioleaching could be attributed to the rising of the microorganism population or galvanic interaction in which graphite acted as the cathode and accelerated the anodic dissolution of pyrite and sphalerite.

Effect of Pyrite Application on Wheat-Maize Growth and Nutrient Uptake Under Diverse Soil Conditions

Zinc (Zn) and phosphorus (P) deficiency is a common nutritional problem for the production of many crops in semi-arid Mediterranean region of Turkey. This problem results in the application of increasing amounts of fertilizers. Minerals (such as pyrite) including iron (Fe) and sulfur (S) can decrease soil pH may be a critical factor in crop production under low supply of Zn and P in calcareous and clay soils. The aim of this research was to determine the effect of pyrite application on wheat-maize-wheat growth, P and Zn concentration with three successive pot experiments. Bread (Seri-82) (Triticum durum L.) durum (Kunduru) wheat (Triticum aestivum L.), and maize (Zea mays L.) RX 788 hybrid was grown in Zn and P-deficient calcareous soils from Central Anatolian Sultanönü and Çukurova Karaburun. Plants were grown under greenhouse conditions at five rates of pyrite (0, 0.5, 1, 1.5, and 2 g pyrite kg−1 soil) in three consecutive experiments. Pyrite application increased shoot dry matter production of wheat and maize. With time effect of pyrite on plant growth and nutrient uptake was more. In accordance with growth data, pyrite application enhanced P and Zn concentration of plants, especially under Zn deficient Sultanönü soil then Karaburun soil. Plants grown in Karaburun soil had more P and Zn concentration than grown in Sultanönü soil. The results obtained indicate that pyrite can be used as a zinc fertilizer sources for gramine plants such as wheat and maize.

The effect of pyrite on Escherichia coli in water: proof-of-concept for the elimination of waterborne bacteria by reactive minerals.

We present proof-of-concept results for the elimination of waterborne bacteria by reactive minerals. We exposed Escherichia coli MG1655 suspended in water to the reactive mineral pyrite (FeS₂) at room temperature and ambient light. This slurry eliminates 99.9% of bacteria in fewer than 4 hours. We also exposed Escherichia coli to pyrite leachate (supernatant liquid from slurry after 24 hours), which eliminates 99.99% of bacteria over the same time-scale. Unlike SOlar water DISinfection (SODIS), our results do not depend on the presence of ultraviolet (UV) light. We confirmed this by testing proposed SODIS additive and known photo-catalyst anatase (TiO₂) for antibacterial properties and found that, in contrast to pyrite, it does not eliminate E. coli under our experimental conditions. Previous investigations of naturally antibiotic minerals have focused on the medical applications of antibiotic clays, and thus have not been conducted under experimental conditions resembling those found in water purification. In our examination of the relevant literature, we have not found previously reported evidence for the use of reactive minerals in water sanitization. The results from this proof-of-concept experiment may have important implications for future directions in household water purification research.

Effect of Pyrite in Precursor on Capacitance Behavior of Prepared Activated Carbon

Analogue sulfur-containing precursors (ASCPs) were employed to prepare activated carbon (AC). Samples were characterized and analyzed by X-ray adsorption near-edge structure spectroscopy, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, ion chromatography, and N2 physical sorption means. The results show that FeS2 in the precursor can react with the activation agent KOH to produce sulfur compounds such as K2SO4, K2S2O3, K2S, and thioether (R-S-R′), and reduce the actual KOH amount used for porosity development, hence decreasing specific surface area and pore volume of AC. This imposes an obviously negative effect on the capacitance and rate capability of the AC electrode as well as producing the byproduct Fe3O4. Consequently, FeS2 content in minerals as supercapacitor AC precursors should be limited to as low as possible in practical application. Furthermore, it is interesting to note that some of the inorganic FeS2 in the precursor can be converted into organic sulfide as a basic part of the resultant AC by undergoing a complex KOH activation process.