Natural Quartz Research Articles

Assessment of Gold-Bearing Quartz Vein as a Potential High-Purity Quartz Resource: Evidence from Mineralogy, Geochemistry, and Technological Purification

High-purity quartz (HPQ) is an important material widely used in many high-tech industries. It is a product processed from pure natural quartz raw materials, so selecting suitable quartz raw material is the key to successfully processing HPQ. Hydrothermal quartz vein is one of the most likely raw materials to be purified into HPQ because of its high SiO2 content. This study focuses on the evaluation of HPQ raw material potential of the two gold-bearing quartz vein tailing resources in Chibougamau (CBG) and Tianjingshan (TJS). Petrography and the contents of impurity elements in the two vein quartz samples before and after processing were studied by optical microscope, SEM, Raman spectrometry, XRD, LA-ICP-MS, and bulk solution ICP-OES. Petrographic results reveal that major impurities in quartz are feldspar, mica, iron compounds, ankerite, rutile, silicate melt, and fluid inclusions. LA-ICP-MS analysis result shows that the SiO2 contents are between 99.953–99.971 wt.% in CBG raw quartz and 99.969–99.976 wt.% in TJS raw quartz, respectively, with very low contents of impurity elements, except for Ca. Bulk solution ICP-OES analysis demonstrates that the CBG processed quartz sand has total impurity contents of 56.8 µg·g−1, with 13.1 µg·g−1 Al and 6.6 µg·g−1 Ti, and the TJS processed quartz sand has the total impurity contents of 85.2 µg·g−1 with 29.4 µg·g−1 Al and 6.1 µg·g−1 Ti. Both the contents of Al and Ti fit with the lattice-bound criteria for HPQ. These results, for most of the impurities, are likely hosted by silicate melt, fluid, and mineral inclusions, indicating that these two hydrothermal raw vein quartz samples can be upgraded to HPQ after processing by more advanced methods. Therefore, the CBG and TJS quartz vein deposits would be considered as potential future resources for HPQ to realize efficient recovery and utilization of tailings resources and to improve mine economic benefits.

Influence of vacuoles with gas–liquid inclusions on the thermobaric destruction conditions of natural quartz under dynamic heating in an RF-TICP torch system

In the present work, the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency (RF) inductively coupled plasma torch was numerically studied. The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach. The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied. It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction. The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined, and a recommendation was given to promote the degree of thermobaric destruction of quartz particles, which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.

A Fractal Description of Finely Ground Particles of Natural Quartz Using Particle Size and Image Analyses

A Fractal Description of Finely Ground Particles of Natural Quartz Using Particle Size and Image Analyses

Ultrafine quartz flocculation: Part I. System characterization and variables selection

A characterization study was performed to verify the more relevant physicochemical properties for quartz flocculation with polyacrylamide, as well as to define which variables should be further investigated regarding this flocculation system. Polyacrylamide was evaluated through molecular weight, radius of gyration, and infrared spectrometry. A natural quartz sample was investigated regarding its particle size distribution, specific surface area, mineralogical and chemical composition. The zeta potential of quartz with flocculant and surfactant was also analyzed. The results indicated that the quartz had high purity and particle sizes between 38 and 10 µm, which was within the intended particle size range; the flocculant presented a suitable molecular weight for the proposed flocculation system. Based on literature, nine variables were chosen to be investigated in Part II of this study: flocculant and surfactant concentration, flocculant and surfactant conditioning time, flocculation addition time, agitation intensity, pH of the suspension, flocculation time, and solid concentration.

NaClO-based rapid sand filter in treating manganese-containing surface water: Fast ripening and mechanism

Recently, seasonal manganese contamination in the surface water is capturing ever-increasing attention and has posed significant challenges to the safety of water supply in the conventional drinking water treatment plants. This study aimed to develop new strategies to enhance the manganese removal by the sand filter. The synergistic effects of filter material type, filter layer thickness, filtration rate, and NaClO addition on the manganese removal performance, were systematically investigated. The results indicated that modified zeolite exerted the highest adsorption capacity (5.200 mg/g) for manganese. Introducing the NaClO oxidation would effectively improve the manganese removal efficiency (from 32 % to 97 %) by the modified zeolite filter compared to the control system at the filtration rate of 8 m/h, owing to the fast formation of catalytic oxidation capability. Accordingly, the effective layer thickness of modified zeolite can be shortened from 100 cm to 10–20 cm to engineer a double-layer filter consisting of both a thin modified zeolite layer and a thick natural quartz sand layer. Besides, NaClO involvement would neutralize the adverse effects of manganese removal caused by the filtration rate increase, and facilitate the formation of auto-catalytic manganese oxides (MnOx) with rough, heterogeneous, and porous surface morphology, as well as numerous tremella-like and sponge-type structures, which was related to the fast removal of manganese. These findings are full of significance in developing simple, practical, and cost-effective strategies for seasonal manganese contamination.

Polyvinylidene fluoride, an advanced futuristic smart polymer material: A comprehensive review

AbstractThere was a fast development of various piezoelectric materials in the past two decades due to their numerous applications. Piezoelectric materials made up of natural quartz crystals were used in ultrasonic detectors in the early days. Later, the modern synthetic piezoelectric materials known as ferroelectric ceramics, such as Lead zirconate titanate (PZT), were developed, which were capable of exhibiting piezoelectricity several times greater than natural crystals. Later, the declination of ceramics began as they contained large amounts of lead content, which was considered harmful to both humans and the environment. Finally, a new era in the history of piezoelectric materials boomed with the outbreak of polymer materials. Polyvinylidene fluoride (PVDF) is a piezoelectric polymer material that has drawn the attention of researchers, from the family of fluoropolymers and has paved a new path in the field of polymer science and technology. PVDF has earned the renown of being an excellent piezoelectric material due to its unique and versatile exhibition of piezoelectric and dielectric properties. Furthermore, PVDF can exhibit incredible thermal stability and mechanical strength with flexible processing and low cost compared with the other piezoelectric crystals and ceramics. This comprehensive review mainly focuses on the evolution of piezoelectric materials from crystals to polymers with their advantages and significant drawbacks. Thus, the main objective of this review is to present a detailed description of PVDF concerning its uniqueness as a piezoelectric material and versatile properties, followed by various advanced fabrication techniques and their impact on doping various nanofillers with respective applications. Though PVDF is renowned for its significant applications such as sensors, actuators, energy harvesting and biomedical devices, a tabular chart has been specially framed in one‐liners which highlights the real‐time experimental outcomes where PVDF can be specified as a futuristic polymer for multifunctional applications. A few reports resulted that with increasing graphite and MWCNT fillers into PVDF film, the EMI shielding effectiveness value rose to 14.64 dB at a frequency of 8‐12 Hz. A few reports resulted that by adding ZnO and BaTiO3, the electrical output increased significantly, which is more suitable as a nanogenerator. After an extensive literature survey, we found that reviews are very limited and restricted to specific applications and properties. This review is an overall brief explanation of enormous research works carried out by various experts and presented in a modest way with pictorial and tabular representation for the convenience of researchers. Finally, this review attempts to provide source material to direct researchers towards a fertile area of research with a better understanding of the fundamentals and advancement of polymer piezoelectric materials.

Adsorption mechanism of basic blue-9 onto quartz mineral: kinetics, isotherms and thermodynamic

Adsorption of basic blue-9 (BB9) by natural quartz mineral was tested. The quartz mineral was characterized by FTIR, SEM, DRX, zeta potential and Sear’s surface area measurements. The quartz mineral contains 99.13% of SiO2 and has a specific surface area of 0.6 m2g−1. The zeta potential measurements of quartz showed a zero point charge (ZPC) at a pH of 2.12. Adsorption experiments results of basic blue-9 showed an excellent achievement after 15 min, for 100 μm sorbent particles seize, 1.0 g l−1 sorbent mass, pH of 5.0, agitation speed of 200 rpm and Temperature of 60 °C. Moreover, the BB9 concentration and temperature were directly related to increase in adsorption capacity and the highest adsorption capacity of 27.78 mg g−1 was achieved for 30 mg l−1 at 60 °C. Langmuir isotherm and pseudo-second-order kinetics (R2 > 0.99) were found to be the most appropriate models to describe the removal of metylen blue dye by quartz mineral. The apparent diffusion parametres were estimated to be between 3.24 × 10–6 and 3.67 × 10–6 cm2 s−1, indicating an adsorption process controlled by the external mass transfert on the quartz surface. The calculated thermodynamic parameters and Dubinin–Radushkevich adsorption free energy (Eads = 0.28 kJmol−1) showed that adsorption of BB9 onto quartz was spontaneous, endothermic and a physisorption reaction. FTIR spectroscopy and semi empirical RM1 calculations established an adsorption mecanism by electrostatic attraction. The regeneration tests after four runs showed that natural quartz could be an alternative material for cationic dyes removal.

Studies on the processing of natural quartz from raw material sources with different amounts of fluid inclusions

This article presents the results of experimental processing of quartz obtained from sources of different genetic types that may potentially be used to generate high-purity quartz raw materials. A combined process was used that included: dry processing of quartz using visual sorting, crushing, screening, and magnetic separation, followed by quartz concentrate processing by flotation, wet magnetic separation, chemical milling, high-temperature calcination, and washing with deionized water. Quartz processing was monitored using inductively coupled plasma (ICP-OES) and quantitative mineralogical analyzes. The amount of fluid inclusions in the quartz was established by the light transmission coefficient in the visible region of the spectrum. The processing technology used allowed achieving a total content of impurity elements (Na, K, Li, Al, Ca, Fe, Ti, B, and P) in the quartz concentrates of 8–22 ppm. The processing did not change the amount of fluid inclusions in the quartz. The processing experiments conducted for quartz from 21 quartz deposits of different genetic types have demonstrated that the quartz concentrates obtained from six granulated quartz sources were suitable in terms of their grade characteristics for direct melting of transparent quartz glass. Additional process solutions are required for the remaining sources, aimed at reducing the amount of fluid and non-structural impurities in the quartz product. Three sources were rejected.The study was carried out under state assignment No. 122062100023-5, with the financial support of the Russian Science Foundation and the Chelyabinsk Region within the framework of scientific project No. 22-27-20077.

Thermoluminescence assessment of quartz veins emplaced in Talc-Schist Metamorphic Rocks, Egypt

The current work is aimed to study the thermoluminescence (TL) properties of natural milky quartz associated with Metamorphic Rocks extracted from the Eastern Desert of Egypt. Atomic absorption spectrometer was used to assess the chemical compositions of the samples, and X-ray diffraction was used to examine the structural properties (XRD). The deconvolution of the glow curve was carried out and revealed that there were ten trapping sites at 0.623, 0.936, 1.02, 1.06, 1.31, 1.47, 1.58, 1.76, 2.49, and 2.96 eV. The linearity of the sample was examined for each glow peak. The analysis of the glow curve was studied also by Tm − Tstop and various heating rates (VHR) giving the kinetics parameters (activation energy E, eV).The minimum detectable dose of the investigated samples was found to be 24 µGy. The dosimeter demonstrated a high level of repeatability. The fading signal was investigated for varying storage times up to 30 days.Graphical abstract

Critical role of the deep electron trap in explaining the inconsistency of sensitivity-corrected natural and regenerative growth curves of quartz OSL at high irradiation doses

Natural quartz minerals that contain impurities, complex defect structures, and multiple trap levels within their crystals have been widely used for optically stimulated luminescence (OSL) dosimetry. Accurate application of the single-aliquot regenerative-dose (SAR) protocol requires an equivalence between the sensitivity-corrected natural and regenerative growth curves. In this work, the sensitivity-corrected natural and regenerative growth curves of quartz OSL are modelled using a comprehensive kinetic model based on the band theory of solids. We demonstrate that the trapping behaviour of the deep electron trap exerts a critical influence on the inconsistency of the sensitivity-corrected natural and regenerative growth curves at high irradiation doses. A delay in saturation of the deep electron trap at high irradiation doses leads to a substantial increase in electron competition in the recombination centres during the irradiation of the test dose and a decrease in electron competition in the centres during the subsequent stimulation of the test dose OSL. As a consequence, the test dose OSL responses as functions of irradiation doses are inconsistent (incompatible) between natural and regenerative aliquots, and the sensitivity-corrected regenerative growth curve tends to be higher than the natural one in the high-dose region. There may be substantial deep electron traps within the crystal of natural quartz that cause their delayed saturation at high irradiation doses.

Kinetics of Magnesiothermic Reduction of Natural Quartz.

In this work, the kinetics of natural quartz reduction by Mg to produce either Si or Mg2Si was studied through quantitative phase analysis. Reduction reaction experiments were performed at various temperatures, reaction times and Mg to SiO2 mole ratios of 2 and 4. Rietveld refinement of X-ray diffraction patterns was used to obtain phase distributions in the reacted samples. SEM and EPMA examinations were performed to evaluate the microstructural change during reduction. The results indicated that the reduction reaction rate was slower at a mole ratio of 2 than 4 at the same temperature, as illustrated by the total amount of Si formed (the percent of Si that is reduced to either Si or Mg2Si to total amount of Si) being 59% and 75%, respectively, after 240 min reaction time for mole ratios of 2 and 4. At the mole ratio of 4, the reaction rate was strongly dependent on the reaction temperature, where SiO2 was completely reduced after 20 min at 1273 K. At the lower temperatures of 1173 and 1073 K, total Si formed was 75% and 39%, respectively, after 240 min reaction time. The results of the current work show that Mg2Si can be produced through the magnesiothermic reduction of natural quartz with high yield. The obtained Mg2Si can be processed further to produce silane gas as a precursor to high purity Si. The combination of these two processes offers the potential for a more direct and low carbon method to produce Si with high purity.

Comparing the monochromatic TL response of a high sensitivity natural quartz irradiated with β and γ rays

This study investigates the effect of the dose-rate in the thermoluminescent glow curves of a single crystal of quartz. The samples were sensitized by the γ radiation combined with the heat-treatments. The glow curves were registered in zeroed (unsensitized) and sensitized conditions using an optical filter centered in violet spectral region. Tens mGy test doses were administered with one β (90Sr/90Y) source and two γ radiation sources (60Co and 137Cs). The TL curves were deconvoluted using a first-order kinetic model. Differences in the glow curves and trapping parameters were observed between zeroed and sensitized samples. Differences were found in the TL curves comparing the three radiation sources. The principal variation is the remarkable increase in the TL signal above 350 °C, which is observed only in sensitized samples with the minor dose-rate source (137Cs). This signal seems to be associated with deep trapping states. The intensities of the components defining the first peak and the high temperature signal show a dependence on the dose-rate. The dose-rate dependence of the first-peak components is explained by the competing effects that may take place during the excitation stage. The components that fitted the sensitized peak (260 oC) do not exhibit a clear dependence on the dose-rate of radiation source.

Effect of blue light bleaching in a high TL sensitivity natural quartz crystal

The quartz dating can be performed from optically stimulated luminescence (OSL) or thermoluminescence signals (TL). The relationship between OSL and TL signals is important to ensure adequate measurement of luminescent signal. The bleaching effect on TL signals have been studied by various works. However, there is no consensus. This study investigates the effect of blue light bleaching in a natural quartz crystal whose TL signal can be recorded with test-doses lower than 1 Gy. As a result, it was found that blue light is capable to erode almost completely de first TL peak. The bleaching effect for TL peaks above 200 °C is limited. However, TL components peaked at 320 and 390 °C are more sensitive to blue light than the intermediate TL components peaking at 250 and 280 °C.

A systematic multi-technique comparison of luminescence characteristics of two reference quartz samples

Further developments in luminescence dating, dosimetry and temperature-sensing require a deep understanding of luminescence processes and their driving parameters. Natural quartz is one of the most widely used minerals for these purposes. Still, poor reproducibility of results often hampers comparability and credibility from findings in the literature. We identified the lack of suitable natural reference samples as a pivotal problem impeding significant progression. Ideally, basic investigations involve several laboratories working on well-characterised reference quartz samples with different characteristics. Investigations should include multiple complementing methods to analyse luminescence properties and mineralogical and geochemical composition.Here, we present such a multi-technique luminescence comparison of two natural quartz samples. Next to the recently introduced Fontainebleau (FB) reference quartz, we propose another reference sample derived from the ‘Silver Sands of Morar’ (lab code ‘MR’; Scotland, UK). Our experiments confirm that both quartz samples behave fundamentally different in terms of signal composition and sensitivity. The comparative characterisation of both samples targeted electron traps via thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques and luminescence centres via radioluminescence and time-resolved OSL spectrometry. In summary, we conclude that all observed differences are likely the results of divergent defect concentrations rather than variances in defects' composition (nature). The measurement data of our study are accessible open-access for inspection by others.

New Quartz And Zircon Si Isotopic Reference Materials For Precise And Accurate SIMS Isotopic Microanalysis

Here we report the Si isotope compositions of four potential reference materials, including one fused quartz glass (Glass-Qtz), one natural quartz (Qinghu-Qtz), and two natural zircons (Qinghu-Zir and Penglai-Zir), suitable for in-situ Si isotopic microanalysis. Repeated SIMS (Secondary Ion Mass Spectrometry) analyses demonstrate that these materials are more homogeneous in Si isotopes (with the spot-to-spot uncertainty of 0.090-0.102‰), compared with the widely used NIST RM 8546 (previously NBS-28) quartz standard (with the spot-to-spot uncertainty poorer than 0.16‰). Based on the solution-MC-ICP-MS determination, the recommended 𝛿30Si values are −0.10 ± 0.04 ‰ (2SD), −0.03 ± 0.05 ‰ (2SD), −0.45 ± 0.06 ‰ (2SD), and −0.34 ± 0.06 ‰ (2SD), for Glass-Qtz, Qinghu-Qtz, Qinghu-Zir, and Penglai-Zir, respectively. Our results reveal no detectable matrix effect on SIMS Si isotopic microanalysis between the fused quartz glass (Glass-Qtz) and natural quartz (Qinghu-Qtz) standards. Therefore, we propose that this synthetic quartz glass may be used as an alternative, more homogenous standard for SIMS Si isotopic microanalysis of natural quartz samples.

Magnesiothermic Reduction of Natural Quartz

In the current work, the metallothermic reduction of natural quartz by magnesium has been studied at 1373 K under different reaction conditions, i.e. quartz type, quartz particle size, Mg:SiO2 mole ratio and reaction time. The microstructure of reaction products was studied to illustrate the reaction progression through scanning and transmission electron microscopy techniques. X-ray diffraction analysis with Rietveld phase quantification was used to calculate the change in the amount of phases at different reaction conditions. The results showed that the Mg:SiO2 mole ratio strongly affects reaction mechanism and product characteristics such as phase content and microstructure. At lower Mg:SiO2 mole ratios, the reaction rate is fast at the beginning and the formation of a product layer consisting of different phases such as MgO, Si, Mg2Si, Mg2SiO4 and MgSiO3 around quartz particles limits the Mg diffusion. This phenomenon is more noticeable for larger quartz particle sizes where Mg should diffuse longer distance towards the quartz core to react with it. At higher Mg:SiO2 mole ratios, a significant amount of Si–Mg liquid alloy is formed during reaction where the high mobility of Mg in this liquid phase and cracking of quartz particles result in significantly higher reaction rate. Here the formation of intermediate phases is not significant and the products would be the mixture of MgO, Mg2Si, and either Si or Mg phases.

Internal Radiation Levels in Natural Quartz Crystals Collected from Southwestern Nigeria; Implications on Thermoluminescence Studies

The relationship between natural thermoluminescence (TL) signal, activity concentrations and the TL sensitivities of twelve (12) quartz samples from different origins were investigated in this study. Gamma spectrometry measurements on the samples were carried out with coaxial-type Germanium detectors (Canberra Industries Inc., Meriden, CT, USA). The TL measurements on the samples were measured using a RISØ TL/OSL reader (model TL/OSL–DA–15). Concentrations of radionuclide activities were only detected in three samples with very low values as compared with world’s average. The highest dose rate in one of the samples was observed to be a factor of 15 lesser than a case of self-dose reported in the literature. The three samples with detectable activity concentrations are the one that possess highest TL signals. All the samples with an exception of one exhibit dependence of sensitization factor of 110 °C TL glow-peak on the equivalent dose (ED). This observation suggested a correlation between the ED of quartz and the sensitization factor of its 110 °C TL peak, an indication of the importance of ED in quartz TL and Optically Stimulated Luminescence (OSL) characteristics. There was no possibility of self-dose effect in all the samples and their radiation safety in exploration and applications in electronics and gemology are validated.

Formation of radiator structures in quartz veins - Phase-field modeling of multi-crack sealing

The present work showcases a comprehensive phase-field study on the formation of multi-crack-seal veins in quartz microstructures. The microstructure simulation framework Pace3D incorporates the modeling of both fracturing and sealing in polycrystalline rock systems, where crystallographic anisotropies, crack resistances and growth velocities of different facets are included in the energy density contributions. In a two grain system we exemplary show the formation of three different archetypes of radiators which are observed in natural quartz veins. We extend the phase-field studies to a polycrystalline host rock and investigate therein the effects of fracture aperture, presence of accessory minerals, and oblique opening trajectories with refracturing of fully and partially sealed veins on the occurring vein crystal morphology. Our results show that the shape of the forming grain boundaries depends on the crystal orientation of the participating grains, the location of a fracture through the crystals, and the sealing state. Evolution of more pronounced radiator structures are found in simulation studies with increasing aperture. A broad spectrum of crystal structures which are frequently observed in natural quartz vein microstructures is reproduced in simulations using the combined crack-seal phase-field model.

Insight into the adsorption and oxidation activity of a ZnO/piezoelectric quartz core-shell for enhanced decontamination of ibuprofen: Steric, energetic, and oxidation studies

• ZnO/quartz was used as a catalyst and adsorbent for the removal of ibuprofen (IBF). • It exhibits receptor sites and adsorption capacity of 38.42 mg/g and 145.6 mg/g. • The adsorption reactions of IBF by ZnO/quartz is of physisorption mechanisms. • 50 mg/L of IBF was oxidized after 80 min (Photocatalyst) and 40 min (Piezo-photocatalyst). • The hydroxyl and superoxide radicals are the main oxidizing species. A natural piezoelectric quartz core was coated with environmentally friendly ZnO nanoparticles (GZn/PQz) for enhanced decontamination of ibuprofen (IBF) by adsorption and advanced oxidation. The adsorption properties were described based on the monolayer model of one energy site. The steric studies demonstrated a decline in active site density (Nm) and the saturation adsorption capacities (Qsat) with increasing temperature, and the best values were achieved at 25 °C (Nm = 38.42 mg/g and Qsat = 145.6 mg/g). The number of adsorbed IBF molecules (n) (>3 and <4) suggested the uptake of 3 or 4 IBF molecules per receptor site in a vertical orientation and by a multimolecular mechanism. The adsorption energy values (−7.93 to −9.5 kJ/mol) suggest physical uptake processes. The thermodynamic functions reflected the exothermic and spontaneous properties of the reactions. GZn/PQz achieved IBF (50 mg/L) oxidation percentages of 100%, 93.8%, and 100% after 80 min (photocatalyst), 360 min (piezoelectric catalyst), and 40 min (piezo-photocatalyst), respectively. Hydroxyl radicals and superoxide radicals are essential oxidizing species during the oxidation of IBF by GZn/PQz. Based on the detected intermediate compounds, the oxidation pathway of IBF by GZn/PQz involved hydroxylation, decarboxylation/demethylation, and ring-opening processes.

불소 오염토양의 기원별 오염특성을 파악하기 위한 광물학적 특성분석 및 세척효율평가

In this study, mineralogical characteristics analysis and extraction characteristics evaluation were performed to identify the contamination characteristics by origin of fluoride-contaminated samples of natural origin by granite mica and artificial fluoride-contaminated samples by waste gypsum fluoride of making fertilizer process. In samples of natural origin, mica, quartz, feldspar, fluorite, and amphibole showed the high mineral content in the order. Among them, mica, which is expected to be the causative mineral of fluorine contamination, consisted of muscovite, biotite, and lithium mica. In artificial fluoride-contaminated samples, quartz, plagioclase, illite, gypsum, sulfur, and wollastonite showed the highest mineral content in the order. Compared to the total mica content and fluorine concentration of the natural origin contaminated sample, a proportional linear relationship(R2=0.68) was shown, and this result is estimated to be the influence of natural origin by minerals in badlock not artificial contamination. When compared with the gypsum content and fluorine concentration of the artificially contaminated samples, a proportional linear relationship(R2=0.79) was shown, and the fluoride concentration was found to exceed the standard in all samples with a gypsum content of about 20 % or more. As a result of the washing efficiency test for each mica fluoride-contaminated sample, it was confirmed that the washing efficiency was relatively low with all washing agents less than 10 %, and hydrochloric acid(HCl) had the highest washing efficiency. In addition, the optimal hydrochloric acid(HCl) concentration was confirmed to be 1 M. As a result of the washing efficiency test for each washing agent for the fluorine-contaminated sample of a fertilizer factory, sodium hydroxide(NaOH) was confirmed to have the highest washing efficiency and showed about 1.5 times higher than hydrochloric acid(HCl). In addition, the optimal concentration of sodium hydroxide(NaOH) is judged to be suitable at 0.5 M, which showed a washing efficiency of 65.6 %. Based on the results of this study, it is intended to be used as a basic data for the development of soil remediation technology considering the method of proving the cause of fluoride-contaminated soil and the characteristics of contamination by origin.