Abstract:Late Jurassic granite in Jiaodong area is mainly exposed in Zhaoyuan, Laizhou, Wendeng, Rushan and other areas, including Linglong pluton and Queshan-Kunyushan pluton. In between, the Qixia region is dominated by Archean TTG-type rocks. This time, many meso-grained monzogranite xenoliths were found in the diorite porphyrite veins (surrounding rock is TTG type rock) in Shangqujia village, Qixia area, the SHRIMP U-Pb age of zircon from monzonitic granite is 161.0±2.2 Ma. The ratio of ¹⁷⁶Hf/¹⁷⁷Hf ranged from 0.281 929 to 0.281 971, the εHf (t) was -26.39 to -24.77, t_DM2 was 2 871 to 2 773 Ma. The monzogranite xenoliths are characterized by high potassium, high aluminum,low magnesium and iron. They are peraluminous, high potassium calc-alkaline rocks, which are deficient in heavy rare earth elements and have obvious fractionation of light and heavy rare earth elements. The ratio of (La/Yb)_N varies from 28.11 to 78.50, there are obvious Eu positive anomalies (Eu/Eu^*=1.16~1.77), and the large ion lithophilic elements Rb, K, Ba and Sr are relatively enriched. Its isotopic geochronology, petrology, and rock geochemical characteristics are basically consistent with those of the Linglong pluton and the Queshan-Kunyushan pluton. It is the result of partial melting of the crust thickened by the collision between the Yangtze plate and the North China plate under the background of the movement of the ancient Pacific plate. The source area is mainly composed of TTG type rocks. This article believes that these diorite xenoliths belong to the Linglong period granite. Based on the interpretation of regional gravity anomalies, it is believed that there is a hidden Linglong period granite body in the lower part of TTG rocks in the Qixia area. It is speculated that the range extends from the Douya fault in the west to the Taocun fault in the east, to the northern edge of the Jiaolai Basin in the south, and to the southern edge of the Zangjiazhuang Basin in the north. The Linglong pluton and the Queshan-Kunyushan pluton may be connected in the deep part.

Abstract:The Houhe Complex is an important part of the early Precambrian basement rocks in northern margin of the Yangtze Block. However, its genesis and tectonic setting are still unclear, which restricted our understanding on the geological evolution of northern margin of the Yangtze Block and even the entire Yangtze Block during the Paleoproterozoic period. In this study, analyses of whole-rock major and trace elements, Sm-Nd isotopes, zircon U-Pb geochronology and in-situ Lu-Hf isotopes are performed on trondhjemite and monzogranite from the Houhe Complex in Beiba area, northern margin of the Yangtze Block. The U-Pb dating results show that the crystallization ages of trondhjemite and monzogranite are 2 101±10 Ma and 2 072±15 Ma, respectively. The trondhjemite samples exhibit the characteristics of high silicon and sodium, low potassium and magnesium. Most samples belong to metaluminous to weakly peraluminous and calc-alkaline I-type granitic rock series and exhibit characteristics of island arc granite. Their zircon εHf(t) values range from -0.8 to + 4.6, with whole-rock εNd(t) values ranging from +0.1 to +1.1 and two-stage Hf model ages (t_DM2) ranging from 3 005 Ma to 2 469 Ma. In contrast, the monzogranite rocks show low silicon, but high magnesium, aluminum and potassium, belonging to weakly peraluminous and high-K calc-alkaline I-type granite. Their total rare earth element concentrations are relatively high. The differentiation between light and heavy rare earth elements is obvious, accompanied by weak negative Eu anomalies. The monzogranite rocks are also enriched in large ion lithophile elements (Rb, Ba and Th), and depleted in high field strength elements (Nb, Ta and Ti). They have high Mg^# values, and Cr and Ni contents, with zircon εHf(t) values of - 2.9~+ 2.4, and whole-rock εNd(t) values of +0.1~+0.9 and two-stage Hf model ages (t_DM2) of 2 939~2 604 Ma. All these data indicate that the trondhjemite was mainly produced by partial melting of Neoarchean basaltic rocks in the lower crust, with a certain degree of fractional crystallization. The monzogranite was generated by partial melting of ancient Neoarchean continental crust caused by underplating of mantle-derived magma, with addition of lithospheric mantle material. Considering the temporal and spatial distribution, and petrogenesis of the late Paleoproterozoic (2.1~2.0 Ga) mafic-felsic magmatic rocks reported in northern margin of the Yangtze block, it is supposed that the Paleoproterozoic (2 101~2 072 Ma) granitoid rocks from the Houhe Complex in Beiba area, northern margin of the Yangtze block, were formed under an active continental margin arc setting, related to convergent process of global Paleoproterozoic Columbia supercontinent.

Abstract:The hydrothermal dolomite (HDS) is a significance ore-bearing wall rock of the MVT Pb-Zn deposit. However, the distribution pattern of hydrothermal dolomite along faults remains unclear, making it as a prospecting indicator of MVT deposit is uncertain. The MVT Pb-Zn ore concentration area in Sichuan, Yunnan and Guizhou on the southwestern margin of the Yangtze platform is generally characterized by HDS ore-endowments. This study focuses on the ore-bearing HDS in the Longjie exploration area of northeastern Yunnan. Through geological mapping and petrographic observation, combined with mineral elemental composition and C-O isotope analysis, and a comparison with buried dolomite, the distribution characteristics of ore-bearing HDS along faults were systematically clarified. The results indicate: ① The ore-bearing HDS is produced along the secondary fracture of the upper disk of the strike-slip normal fault or thrust fault, and the distribution range along the upper disk of the fault is larger than that of the lower disk of the fault. HDS is formed by accounting limestone or dolomite on both sides of the fault. The closer the distance from the fault, the shallower the color, and the larger the crystal size of dolomite. ② The contents of V, Cr, Cu, Zr, Rb and Ba in HDS are higher than those in buried dolomite, and the farther away from the fault, the higher the content is. The distribution pattern of rare earth elements is right-inclined, there are δCe negative anomalies (0.61~0.98) and δEu weak positive anomalies (0.74~1.07), both of which decrease symmetrically away fromt the fault. ③ The dolamitization of HDS in the area occurred in a reduced environment and underwent a process from burial to tectonic hydrothermal alteration, with fluid migrating to both sides along the fault. Therefore, the contents of V, Rb, Zn, Pb and δ¹³C value of HDS increase from the fault to the surrounding rock, which can sever as effective exploration indicators for MVT Pb-Zn deposits.

Abstract:The BIF-type iron deposit at Sijiaying in eastern Hebei Province is considered one of the most representative banded iron deposits in China. A systematic investigation of ore and mineral characteristics holds significant implications for understanding the metallogenic evolution of BIF-type iron deposits. In this study, we conducted comprehensive petrographic observations on various typical iron ores from this mining area, and combined them with in situ electron probe (EPMA) testing and analysis, five distinct magnetite types were identified. Furthermore, we identified four stages of metallogenic evolution: the initial sedimentary stage, metamorphic deformation stage, hydrothermal alteration stage, and epigenetic oxidation stage. EPMA results were obtained for magnetite, biotite, chlorite, and hornblende. By analyzing the chemical characteristics of magnetite and calculating the different formation temperature of biotite and chlorite, and considering changes in the metallogenic environment indicated by their chemical characteristics, it indicated that a typical feature of sedimentary metamorphism is present in the early stage of the deposit and that it suffered from metamorphism, deformation, and hydrothermal effects in the later stage. Combined with geological features, petrographic characteristics of ore minerals and gangue minerals, major element analysis, and other studies, we considered that the oxidation after uplifting to the surface had less influence to the deposit; the enrichment of Fe may be related to the migration of elements such as Mg, Mn, and Ca. The end of the metamorphic deformation stage to the hydrothermal alteration stage is the most important stage for the formation of Fe-rich iron ore in the BIF-type iron deposit at Sijiaying in eastern Hebei Province.

Abstract:The Waxing Mo polymetallic deposit is a newly discovered porphyry type deposit in the Lesser Xing'an Range-Zhangguangcailing metallogenic belt. There are several periods of magmatic activity in the mine area. Zircon U-Pb dating results show that the emplacement ages of monzonite granite, granodiorite and biotite monzonite are 177±1.9 Ma~174±1.2 Ma, 170±1.9 Ma~169±2.1 Ma, and 172±1.5 Ma~172±1.4 Ma, respectively. The three types of granites are all characterized by high SiO₂ (64.41%~77.77%) contents, and are enriched in large ion lithophile elements, depleted P₂O₅ (0.02%~0.21%) and high field strength elements such as Nb and Ta. The A/CNK values are between 0.99 and 1.21], suggesting they belong to high-K calc-alkaline metaluminous-slight peraluminous type I granite. The whole rock Nb/Ta ratio (7~13) is comparable to that of the crust. Zircon εHf(t) values range from 3.9 to 18.8, indicative of juvenile crustal origin. A number of mafic microgranular enclaves (MMEs) are observed in these granitoids, suggesting that mantle-drived magma was involved in the source region. Combined with the regional tectonic evolution history, we believe that the granite in the Waxing ore field was formed in the late collision-post-collisional setting. We found that granodiorite and biotite monzonitic granite have good spatial relationship with Cu-W and Mo-W mineralization, respectively, and their emplacement ages are correlated with the weighted average age of molybdenite Re-Os (169.0±2.2 Ma; MSWD=0.042). These support the granodiorite and biotite monzonitic granite are syn-mineral intrusion, while the monzonite is pre-mineral pluton. Combined with zircon U-Pb chronology and Hf isotope characteristics, the biotite monzonite granite and granodiorite may be the products of different magmatic evolution degrees at the same time, and higher evolution degrees may be conducive to Mo enrichment in magmas. Ratios of granite (La/Yb)_N decrease abruptly from pre-mineral to syn-mineral intrusions, probably indicating a transition from compression to extension, which may be conducive to Mo formation.

Abstract:Uraninite is a typical mineral of uranium-bearing granite and the most important source mineral of uranium for the formation of granite-related uranium deposits. Understanding its compositional characteristics and crystallization age is significant for revealing the uranium mineralization process. The Xiazhuang uranium ore field in northern Guangdong is an important granite-related uranium deposit in China. In this study, textures and chemical ages of uraninite from the Xiazhuang granite and the altered granite at the Shituling uranium deposit were investigated using EPMA. The results indicate that uraninite in the Xiazhuang granite (Urn-1) is enclosed in rock-forming minerals, and the uraninite near the ore granite of the Shituling uranium deposit (Urn-2) is intergrown with pyrite and occurs between rock-forming minerals. EPMA data yielded the chemical ages of 233±3 Ma and 156±2 Ma for Urn-1 and Urn-2, respectively. The former is consistent with the zircon U-Pb age of the Xiazhuang granite, indicating that Urn-1 is of magmatic origin. Hydrothermal alteration of the altered granite mainly includes muscovitization and chloritization, corresponding to the early stage of uranium mineralization of the Shituling deposit. These altered samples have higher whole-rock U contents (55.5×10^-6~118×10^-6) and lower Th/U ratios (0.15~0.35) relative to the fresh rocks, indicating that these samples were influenced by uranium-rich fluids, and Urn-2 crystallized from that fluid, suggesting a hydrothermal origin. The chemical age of Urn-2 further indicates that uranium mineralization of the Shituling uranium deposit took place at the Late Jurassic. Some uraninites have been altered, and UO₂ contents of the altered domains are 33.83%~56.01%, obviously lower than the unaltered domains (UO₂=86.21%~95.91%), which may suggest the mobilization and mineralization of uranium related to hydrothermal activity.

Abstract:The detrital composition is one of the key factors affecting the diagenesis and reservoir physical properties of tight sandstone reservoirs. In order to find out the control mechanism of the deformable compositions on the reservoir, taking the Shanxi Formation in the H well area of the Daniudi gas field as an example, through microscopic observation and statistics of rock thin section, combined with the physical properties, we analyse the controlling effect of deformable compositions on diagenesis, and then discuss their control and mechanism on the reservoir. The results show that the plastic composition of the Shanxi Formation is a tuffaceous matrix, and the semi-plastic compositions include tuff, slate, phyllite, schist, and mudstone detritus. The deformable components mainly control the reservoir through compaction and dissolution, and the compaction pore reduction rate is positively correlated with the content of deformable compositions, in which the effect of tuffaceous matrix on the compaction pore reduction is relatively obvious; the dissolution pore enhancement rate is negatively correlated with the content of semi-plasticity and weakly positively correlated with the content of tuffaceous matrix. The content of deformable compositions is negatively correlated with reservoir physical properties, with the fully plastic tuffaceous matrix having a weaker destructive effect on reservoir physical properties. The deformable compositions exacerbate the densification of the reservoir during compaction, and at the same time reduce the flow of diagenetic fluids, but the tuffaceous matrix completely fill the intergranular pore space after compaction, and the effect is more significant. The tuffaceous matrix as the solute of intergranular dissolution, its dissolution is also conducive to the improvement of the physical properties of the reservoir; when the content of the tuffaceous matrix ranges between 8%～12%, it is the most conducive to the formation of better quality reservoirs.

Abstract:The Weining Beishan polymetallic mining area in Ningxia is one of the important metal mineral mineralization areas in Ningxia. At present, multiple ore deposits (points) have been discovered in the research area, including Jinchangzi gold mine and Errenshan lead silver mine. The Errenshan silver lead polymetallic deposit is a shallow low-temperature hydrothermal type and is currently the largest known silver lead polymetallic deposit in the region. With the further deepening of ore exploration in Errenshan, there is an urgent need for further in-depth research on ore exploration models and prediction in the area, in order to further expand the resources and exploration achievements. This article takes the Errenshan silver lead polymetallic deposit as the research object, uses short wave infrared technology (SWIR) to scan the borehole core, determine the types, relative content, and distribution characteristics of altered minerals in the core, and reveal the relationship between the changes in spectral parameters of altered minerals and mineralization intensity. The shortwave infrared technology is used to measure muscovite group minerals, kaolinite group minerals, carbonate minerals, montmorillonite group minerals, etc. Sericite group minerals and carbonate minerals are the through minerals of the borehole, kaolinite, montmorillonite, chlorite and sulfate minerals are only a small amount distributed in the borehole, and the altered mineral combination in the mineralization section is sericite+kaolinite+a small amount of carbonate minerals. By calculating the characteristic parameters of sericite Al—OH spectrum, it is found that the characteristic absorption peak of sericite Pos 2 200 nm and the IC value of sericite crystallinity have a good correlation with mineralization. In high-grade mineralized areas, the overlapping area of Pos 2 200(＜2 204 nm) and sericite crystallinity (IC value)>2.5 can serve as an important indicator or prospecting marker for exploring such deposits in Weining Beishan area.

Abstract:Fused quartz crucible produced from high purity quartz (HPQ) sands is an essential material in which monocrystalline silicon ingot is grown by a process called the Czochralski process, and therefore plays an important role in solar photovoltaic cell and semiconductor industries. Almost all HPQ sands used for fused quartz crucible production in China come from overseas HPQ deposits in USA and India. Investigations on foreign HPQ ores with focus on impurities occurrences, beneficiation test, and resources potential evaluation are pivotal for HPQ deposits prospecting in China. In this study, I used a combination of multiple analytical techniques to conduct petrographic analysis, process mineralogical investigation and beneficiation test on a high purity quartz ore from northern India. My efforts reveal that quartz crystals from the ore material are relatively equant in size and largely devoid of liquid-gas inclusions. The existing liquid-gas inclusion assemblages predominately occur along grain boundaries of quartz crystals, and diffusive inclusion assemblages are extremely rare. Identified gangue minerals, in order of frequency, are Fe-bearing muscovite, iron oxides, ilmenite, zircon, monazite, brabantite, rutile, and mainly embedded among quartz crystals. Based on the impurities occurrence features of the Indian HPQ ore, refinement flowsheet composed of crushing-grinding, sorting, calcination, water quenching, high gradient magnetic separation, flotation, acid leaching, and hot chlorination was carried out, and end products were verified as 4N8 grade HPQ sands (total concentrations of 15 trace elements < 20×10^-6, SiO₂ content > 99.998%). By comparison with IOTA CG HPQ sands, the 4N8 grade HPQ sands extracted from the Indian HPQ ore were deemed to be used to produce outer layer of quartz crucible. Implications for HPQ ore prospecting in China deduced from this investigation practice on the Indian quartz-crucible-grade HPQ ore could be concluded as follows. Resources evaluation on potential HPQ ore in conjunction with process mineralogical study and beneficiation test is an essential prerequisite for deposits prospecting. Given the current political-economic environment, I recommend that the Chinese government designate the HPQ raw material as a unique mineral resource and enroll it on the National Strategic Mineral List. Subsequently, a general specification for HPQ ore exploration is needed with great urgency. In order to create domestic breakthrough on HPQ ore prospecting and resolve the dilemma that supply chain of HPQ sands used for solar and semiconductor industries relies heavily on USA and India, the domestic sections of HPQ deposits prospecting and exploration, HPQ sands extraction, HPQ products fabrication, and application end user should work collaboratively under the government organization and supervision.

Abstract:The chemical speciation characteristics of heavy metals (As, Cd, Cr, Cu, Hg, and Pb) in soils along the banks of the Dawu River, Fuxi River, and Le'an River (Dexing section), adjacent to the Dexing copper mining area, were systematically investigated using the modified seven-step sequential extraction procedure developed by Tessier. The study focused on the concentration profiles, spatial distribution patterns, and inter-element correlations of these metals. The findings demonstrated a high degree of uniformity in the average distribution of specific chemical species across different heavy metal elements within the study area. The chemical speciation profiles generally exhibited a multimodal distribution pattern, with Cd, Cu, and Hg displaying pronounced spatial variability in their respective speciation. The maximum proportion of bioavailable fractions of As, Cd, and Cu was identified in soils from the Le'an River basin (Dexing section), while Hg and Pb reached their highest proportions in the Dawu River and Fuxi River basins, respectively. The bioavailable fraction of Cr showed negligible variability across the three basins. Statistically significant correlations were observed among the chemical species of Cu, Hg, and Pb, indicating notable interactions. The interconversion among chemical species was predominantly regulated by soil environmental parameters such as pH and Eh, which also played a critical role in determining the mobility and bioavailability of heavy metals. The study concluded that mining activities in the Dexing region are the principal contributors to heavy metal contamination in local soils. Consequently, remediation strategies for polluted soils in this area should prioritize managing the release and equilibrium of carbonate-bound and organic matter-bound forms to mitigate environmental risks effectively.

Abstract:Bauxite-based mineral composites (BMC) with LiCl ·2 Al(OH)₃·n H₂O as the core component were prepared from natural bauxite and used for the separation and enrichment of lithium in deep brine of CXD 1 well. The adsorption and desorption properties of Li⁺ of BMC were investigated in simulated solution and real brine. The simulated Li⁺ solution adsorption results demonstrated that the adsorption kinetics were well simulated by the pseudo-second-order model, and the Langmuir model was compatible with the adsorption data, with a maximum Li⁺ capacity of 2.78 mg/g at 298 K. The results of the separation and enrichment study of Li⁺ in the deep brine of CXD 1 well showed that the adsorption rate of Li⁺ in the brine reached 86.38% at the dosage of 1.0 g/25 mL of BMC, and that Li⁺ was adsorbed with good selectivity in the presence of competing ions, such as Na⁺, K⁺, Ca²⁺ and Mg²⁺. After 5 times of adsorption and regeneration, the adsorption capacity decreased by 10.64%. After the removal of impurities by ion exchange resin, the Li⁺ in the eluate was enriched by Na₂CO₃ precipitation, and the Li₂CO₃ yield could reach up to more than 80%. The prepared Li₂CO₃ had comparable properties with commercial analytical purity Li₂CO₃. It can be seen that the BMC used in this paper had potential application in the extraction of Li⁺ from real brine.

Abstract:To analyze the effects of microorganisms and clay minerals on the amount, mineral type, and mechanism of carbonate mineral precipitation, Cladosporium and illite, which can induce dolomite precipitation, were used as exogenous factors to simulate the conditions suitable for the survival of Cladosporium. The induced precipitation of carbonate minerals in marine solutions was investigated through an experiment, using a nutrient broth culture medium with Mg²⁺/Ca²⁺=8, at 30℃. The culture period was set to 1, 3, 5, 10, and 15 days. Following the culture, the pH value was recorded, and Mg²⁺ and Ca²⁺ concentrations were sampled and measured, whereupon the precipitates were collected for analysis via scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction to examine the effects of different precipitation systems on the precipitation of carbonate minerals. The experimental results revealed many types of precipitates underlying the microbial precipitation system, including high-magnesium calcite and micron-sized protodolomite minerals. In clay mineral precipitation, the precipitates comprised mainly high-magnesium calcite, calcite, and nanoscale protodolomite. In the co-precipitation system, where the results of multiple tests were similar to those obtained in the clay mineral system, the precipitates were primarily calcite and dolomite nanospheres, suggesting that clay minerals do not promote the formation of carbonate minerals induced by microorganisms. Therefore, as a microorganism, Cladosporium has a greater impact on the quantity and rate of carbonate mineral precipitation than illite, and this may be because microorganisms can continuously provide carbonate ions into the precipitation system solution, thus accelerating the precipitation of carbonate minerals.

Abstract:To enhance the utilization ratio of silicon from potassium feldspar in the hydrothermal synthesis process of kaliophilite and address the issue of alkaline waste liquid produced by this process, this research carried out the filtrate recycling experiment in the hydrothermal synthesis system of potassium feldspar to kaliophilite. The effects of reaction time, reaction temperature, the molar ratio of SiO₂ to Al(OH)₃ and alkali concentration on Si utilization and product structure were discussed, as well as by investigating the reaction process. The effect of the number of cycles on the utilization ratio of silicon, the structure of the product and the stability of the process were investigated by the circulating experiment of the filtrate under the optimal conditions. The reaction mechanism was further explored and the process before and after the improvement was compared. The results demonstrate that when the reaction time was 4.0 h, the reaction temperature was 280℃, the molar ratio of SiO₂ to Al(OH)₃ was 0.8, and the alkali concentration was 12 mol/L, the utilization ratio of silicon in potassium feldspar could attain 94.2%, representing an increase of 60% compared to the process was improved. The product kaliophilite was homogeneous, superior quality and the recycling process was stable.

Abstract:Vanadium and its compounds, as important strategic resources, are widely used in core fields such as metallurgy, chemical industry, aerospace, national defense and military due to their special physical and chemical properties. How to recover vanadium resources from vanadium slag in a low-cost, green and efficient manner, is an important measure to ensure the sustainable development of China's vanadium industry. This article systematically summarizes the current research status of major vanadium extraction processes at home and abroad, including roasting (non-salt roasting, sodium-roasting and calcium-roasting)-leaching (water-leaching, acidic-leaching and alkaline-leaching)-recovery (hydrolysis, ammonium precipitation, solvent extraction and ion exchange)-calcination, and looks forward to the future research directions of vanadium extraction processes to achieve high-efficiency, low-cost, and pollution-free green development of vanadium extraction processes.

Abstract:Due to the insufficiencies of traditional sampling and quantitative characterization methods for oil shale formation, this paper proposed a new approach for rock classification and sample selection based on the study of the shale oil well section in the Mahu Depression. The approach combines dual-energy CT and MaipSCAN mineral scanning electron microscopy data and takes into account rock density, photoelectric index, and mineral identification. Clustering analysis is utilized for the classification. The proposed method is then applied to identify prevalent formations. An innovative representative rock sample selection method and process are introduced that considers macroscopic heterogeneity. The results show good consistency between the photoelectric index-density classification and minerals, and the clustering classification method is capable of further fine sample selection. Layers with high plagioclase content exhibit better oil and physical properties and can serve as geological and engineering sweet spots. The proposed classification method and sample selection process are reliable and provide new ideas and methods for the systematic evaluation of oil shale reservoirs.