Mineralogy and Chemistry Characterization of the New Basaltic Intrusion at Maasser El Chouf/Lebanon

The importance of this study is to identify the newly reordered and recognized basaltic intrusion for the first time in Maasser El Chouf in Lebanon. The recorded basaltic intrusion cut the Jurassic-Lower Cretaceous rock in this area. Necessary field inspection, geology, mineralogy and chemical tests were carried out on 8 basalt samples to determine their mineralogy, petrography and chemical composition. Representative samples have been tested with polarizing microscope, X-ray diffraction (XRD) and X-ray fluorescence (XRF). Petrographic and mineralogical studies show that the basalt is characterized by presence mainly of calcic-plagioclase feldspar, pyroxene-augite and olivine minerals. Secondary minerals of iron oxides also present (ilmenite and magnetite). The most appeared property is the alteration of olivine mineral to iddingsite that indicated highly weathered process. The composition of the basaltic samples reflects ultrabasic-basic type (Basanite-Tholeiitic basalt). The existence of volcanic activity occurred mostly with Pliocene age (< 2 Ma) as indicated by previous studies for similar basalt in Lebanon. Possibly, these boulders have been carried up from some deeper intrusive magmatic body under very active tension zones. Volcanism of Lebanon basalts belong to the alkaline olivine basalt, suite generally associated with tension, rifting and block faulting movements of the continental crust. Most of the volcanisms in Lebanon and in Harrat Ash Shaam Basalt from Syria and Palestine through Jordan to Saudi Arabia are related and connected to the opening of the Red Sea Rift System, making the area with tremendous volcanic tectonic activities.

Evaluation of VSK separation in the classification of two mineralogically different iron ore fines

With gradually diminishing Fe grade in tandem with the ever-increasing demand for high-grade iron ores,iron ore industries are now focusing on the beneficiation of low-grade iron ore fines,mainly considered waste.Besides,the scarcity of water at many of the mines’sites and the new water conservation policies of the governments have necessitated research on suitable dry beneficiation routes.In this context,an effort has been made to evaluate the efficacy of a dry classification unit,such as the VSK separator,in upgrading the iron values of two low-grade Indian iron ore fines,named Sample 1 and Sample 2.The mineralogical studies,involving scanning electron microscopy and X-ray diffraction,suggest that Sample 1 is a low-grade blue dust sample(51.2wt%Fe)containing hematite and quartz as the major minerals,while Sample 2(53.3wt%Fe)shows the presence of goethite in addition to hematite and quartz.The experiments,carried out using Box-Benkhen statistical design,indicate that blower speed,followed by feed rate,is the most influencing operating parameter in obtaining a good product in the VSK separator.At optimum levels of the operating factors,a fines product with~55wt%Fe at a yield of~40%can be obtained from Sample 1,while Sample 2 can be upgraded to~56wt%Fe at a yield of~85%.The results suggest that the VSK separator can be employed as an efficient intermediate unit operation in a processing circuit to upgrade the iron contents of iron ore fines.

Microwave-assisted reduction roasting–magnetic separation studies of two mineralogically different low-grade iron ores

The microwave-assisted reduction behaviours of two low-grade iron ores having a similar Fe content of 49wt%but distinctly different mineralogical and liberation characteristics were studied.Their performances in terms of the iron grade and recovery as obtained from statistically designed microwave(MW)roasting followed by low-intensity magnetic separation(LIMS)experiments were compared.At respective optimum conditions,the titano-magnetite ore(O1)could yield an iron concentrate of 62.57%Fe grade and 60.01%Fe recovery,while the goethitic ore(O2)could be upgraded to a concentrate of 64.4%Fe grade and 33.3%Fe recovery.Compared with the goethitic ore,the titanomagnetite ore responded better to MW heating.The characterization studies of the feed and roasted products obtained at different power and time conditions using X-ray diffraction,optical microscopy,vibrating-sample magnetometry,and electron-probe microanalysis explain the sequential reduction in the iron oxide phases.Finally,taking advantage of the MW absorbing character of the titano-magnetite ore,a blend of the same with the goethite-rich ore at a weight ratio of 60:40(O2:O1)was subjected to MW roasting that resulted in a concentrate of 61.57%Fe grade with a Fe recovery of 64.47%.

Study on mixing and segregation behaviors in particulate fluidized bed system for mineral processing

In order to identify the mixing and segregation behaviors in a mineral processing operation, present study aimed on the hydrodynamics of solid–liquid fluidization. The study was carried out in a fluidization column with tapings at different height of the bed to collect the sample. The binary particles considered in this study are hematite(4800 kg/m3) and quartz(2600 kg/m3) at different size fractions in the range of average size 87×10^(-6)m to 400×10^(-6)m. It is observed that for various binary mixtures, both quartz and hematite particles share the equal composition by mass(50%) at a particular height of fluidized bed, referred as ‘‘locus point'' of mixing. Study indicates that the mixing zone volume will increase for a continuous fluidized bed plant operation. It is observed that the number of locus points varies from 1 to 3 signifying their dependency on the size ratios of binary mixture. Whenever, the difference in terminal velocity between quartz and hematite particles approaches to zero, mixing is enhanced.Further, the present study is extended to find the segregation index for the different size ratios of quartz and hematite particles. It is evident that depending on the size ratios, various regions such as complete segregation, partial mixing and complete mixing can be observed.

Integrating artificial neural networks and geostatistics for optimum 3D geological block modeling in mineral reserve estimation:A case study

In this research, a method called ANNMG is presented to integrate Artificial Neural Networks and Geostatistics for optimum mineral reserve evaluation. The word ANNMG simply means Artificial Neural Network Model integrated with Geostatiscs, In this procedure, the Artificial Neural Network was trained, tested and validated using assay values obtained from exploratory drillholes. Next, the validated model was used to generalize mineral grades at known and unknown sampled locations inside the drilling region respectively. Finally, the reproduced and generalized assay values were combined and fed to geostatistics in order to develop a geological 3D block model. The regression analysis revealed that the predicted sample grades were in close proximity to the actual sample grades, The generalized grades from the ANNMG show that this process could be used to complement exploration activities thereby reducing drilling requirement. It could also be an effective mineral reserve evaluation method that could oroduce optimum block model for mine design.

Investigating the first-order flotation kinetics models for Sarcheshmeh copper sulfide ore

This study was performed in two phases of work.In the first stage,four conventional first-order flotation kinetics models were fitted to the measured recoveries data and the best model were selected.In the second stage,influence of pH,solid concentration,water chemistry and the amount of collector dosage were investigated on kinetics parameters including flotation rate constant and ultimate recovery.The results indicated that that perfectly mixed reactor model and Kelsall model gave the best and the weakest fit to the experimental data,respectively.It was observed that flotation rate constant and ultimate recovery were strongly affected by chemical factors investigated especially water quality.The flotation rate constant decreased with increasing the solids content,while ultimate recovery increased to certain value and thereafter reduced.It was also found that the most values of flotation rate constant and ultimate recovery obtained in dosage of collector are 30 and 40 g/t,respectively.

Application of laser scanning for rock mass characterization and discrete fracture network generation in an underground limestone mine

Terrestrial laser scanning(TLS) is a useful technology for rock mass characterization. A laser scanner produces a massive point cloud of a scanned area, such as an exposed rock surface in an underground tunnel,with millimeter precision. The density of the point cloud depends on several parameters from both the TLS operational conditions and the specifications of the project, such as the resolution and the quality of the laser scan, the section of the tunnel, the distance between scanning stations, and the purpose of the scans. One purpose of the scan can be to characterize the rock mass and statistically analyze the discontinuities that compose it for further discontinuous modeling. In these instances, additional data processing and a detailed analysis should be performed on the point cloud to extract the parameters to define a discrete fracture network(DFN) for each discontinuity set. I-site studio is a point cloud processing software that allows users to edit and process laser scans. This software contains a set of geotechnical analysis tools that assist engineers during the structural mapping process, allowing for greater and more representative data regarding the structural information of the rock mass, which may be used for generating DFNs. This paper presents the procedures used during a laser scan for characterizing discontinuities in an underground limestone mine and the results of the scan as applied to the generation of DFNs for further discontinuous modeling.

Evaluation of flocculation characteristics of kaolinite dispersion system using guar gum:A green flocculant

This paper reports the systematic investigation on the flocculation,sedimentation and consolidation characteristics of kaolinite using guar gum as a green flocculant.In-situ flocculation behavior of kaolinite at various pH,guar gum dosages,and ionic strength were studied using a light scattering technique.The effect of these parameters on the settling rate,solid consolidation,and supernatant liquid clarity was recorded.The morphology of kaolinite and flocculated kaolinite aggregates were analyzed using FESEM.The morphology studies suggest that it is poorly crystalline with multiple steps on edge,broken edge;laminar with high aspect ratio and have rough basal surface.The complex irregularity on the basal surface and the presence of multiple steps in the edges,broken edges(hydroxyl groups)have facilitated the guar gum adsorption.The isoelectric point of kaolinite is pH 3.96.The pH,ionic strength and flocculant dosage have a significant effect on the kaolinite settling rate.The guar gum has exhibited excellent turbidity removal efficiency at pH 5.The turbidity removal is inefficient at pH 10.However,guar gum has shown high turbidity removal with 80%transmission at pH 10 in the presence of a KNO3 electrolyte.

Study on kinetics of thermal decomposition of low LOI goethetic hematite iron ore

In the present study, the kinetics of thermal decomposition of hydrated minerals associated in natural hematite iron ores has been investigated in a fixed bed system using isothermal methods of kinetic analysis. Hydrated minerals in these hematite iron ores are kaolinite, gibbsite and goethite, which contribute to the loss on ignition(LOI) during thermal decomposition. Experiments in fixed bed have been carried out at variable bed depth(16, 32, 48 and 64 mm),temperature(400-1200 ℃) and residence time(30,45, 60 and 75 min) for iron ore samples. It is observed that beyond a certain critical bed depth(16 mm), 100% removal of LOI is not found possible even at higher temperature and higher residence time. Most of the solid-state reactions of isothermal kinetic analysis have been used to analyze the reaction mechanism. The raw data are modified to yield fraction reacted "α" versus time and used for developing various forms of "α" functions.f(α) is the inverse of first derivative of g(α) with respect to α. The study demonstrates that decomposition of hydrated mineral in hematite follows the chemical kinetics.The estimated activation energy values in all the experimental situations are found to high, of the order of 60 kJ/mol, reinstating that the reactions are indeed controlled by moving phase boundary and random nucleation.

Ground control monitoring of retreat room–and–pillar mine in Central Appalachia

In order to study pillar and overburden response to retreat mining, a ground control program was conducted at a Central Appalachian Mine. The program consisted of several monitoring methods including a seismic monitoring system, borehole pressure cells in the pillars, and time-lapse photogrammetry of the pillar ribs. Two parallel geophone arrays were installed, one on each side of the panel with the sensors mounted 3 m into the roof. A total of fourteen geophones recorded more than 5000 events during the panel retreat. A MIDAS datalogger was used to record pressure from borehole pressure cells(BPCs)located in two adjacent pillars that were not mined during retreat. A series of photographs were taken of the pillars that had the BPCs as the face approached so that deformation of the entire rib could be monitored using photogrammetry. Results showed that pillar stability and cave development were as expected. The BPCs showed an increase in loading when the face was 115 m inby and a clear onset of the forward abutment at 30 m. The photogrammetry results displayed pillar deformation corresponding to the increased loading. The microseismic monitoring results showed the overburden caving inby the face, again as expected. The significance of these results lies in two points,(1) we can quantify the safe manner in which this mine is conducting retreating operations, and(2) we can use volumetric technologies(photogrammetry and microseismic) to monitor entire volumes of the mine in addition to the traditional point-location geotechnical measurements(BPCs).

FRACTIONAL HALANAY INEQUALITY AND APPLICATION IN NEURAL NETWORK THEORY

The (integer order) Halanay inequality with distributed delays is extended to the fractional order case. It is proved that solutions decay to zero as a Mittag-Leffler function as time goes to infinity provided that the delay feedback are bounded by similar functions.An application to a problem arising in neural network theory is provided showing that the equilibrium is Mittag-Leffler stable.

Benefciation studies on recovery and in-depth characterization of ilmenite from red sediments of badlands topography of Ganjam District,Odisha,India

This paper deals with the recovery of ilmenite mineral from red sediments of badlands topography and suggested flowsheet with material balance.The results of these investigations reveal that the red sediment samples contain 33.2%total heavy mineral,in which ilmenite mineral concentrate is 28.71%(by weight).The ilmenite concentrate recovered from red sediment sample by physical benefciation process,which included scrubbing,desliming,gravity concentration,magnetic and electrostatic separation,contains 99.41%grade with 97.3%recovery.The ilmenite mineral concentrate recovered from red sediments is also suitable for industrial applications.The characterization studies on ilmenite reveal that the TiO2percentage is marginally increasing from 46.69%to 47.86%with increasing magnetic intensity from0.46 to 1.55 T.

Improved recovery of a low-grade refractory gold ore using flotation–preoxidation–cyanidation methods

In this work, different flotation–preoxidation–cyanidation methods are considered for treating a lowgrade refractory gold ore. On the one hand, the results of selective flotation show that 22% and 31.1%of total Sb and As, respectively, remained in the final tailings and only about 28% of the total Au remained for further cyanidation processes. On the other hand, in bulk method of flotation the maximum Au recovery of 90.6% achieved after 60 min of flotation at the grind size with K80 of 146 micron. In addition, the bulk flotation method resulted in the concentrate with low concentrations of Sb and As elements. To improve the recovery of low-grade refractory gold ores, flotation should be followed by roasting, biological, or pressure oxidation processes so that the gold could be liberated prior to cyanidation processes. It is also found that the pressure oxidation pre-treatment of the concentrates prior to cyanidation may yield high gold recoveries of over than 83%. In these processes, recoveries are controlled by the temperature and the oxygen partial pressure in the solvent. However, by utilizing the bio-oxidation technique, the oxidation of sulfur to sulfate cannot be completed and, consequently, the gold recovery may be limited to only 72.2%.

A primary study of simultaneous leaching of silver containing manganese ore and a sphalerite concentrate

It is demonstrated that a low grade, silver containing manganese deposit can be exploited by reaction with a ZnS concentrate. In the process, Mn(IV) is reduced to Mn(II) and the ZnS converted to ZnSO4. In the process, Mn and Zn are solubilized. By studying the effects of quantity of reducing agent and sulfuric acid added and of time, temperature and liquid-to-solid ratio on the leaching process, the optimum technological conditions have been achieved under which the amount of manganese leached was 98 %. The silver can be removed from remaining solids by adding ammonia liquor. Then by adding hydrazine hydrate, sponge silver with purity up to 99 % can be obtained with a recovery of 87 %.

EXPONENTIAL DECAY FOR A VISCOELASTICALLY DAMPED TIMOSHENKO BEAM

Of concern is a viscoelastic beam modelled using the Timoshenko theory. It is well-kimwn that the system is exponentially stable if the kernel in the memory term is sub- exponential. That is, if the product of the kernel with an exponential function is a summable function. In this article we address the questions： What if the kernel is tested against a different function （say Gamma） other than the exponential function？ Would there still be stability？ In the affirmative, what kind of decay rate we get？ It is proved that for a non- decreasing function ＂Gamma＂ whose ＂logarithmic derivative＂ is decreasing to zero we have a decay of order Gamma to some power and in the case it decreases to a different value than zero then the decay is exponential.

Research on Technology of Pressure Pretreatment with Oxygen for Refractory Gold Ores

An combined technology of pressure pretreatment with oxygen on refractory gold ores is pointed out and discussed on this paper, according to the experiments included the test in 1 kg grade batch pressure pretreatment with oxygen of the concentrate from the refractory gold ores of Dongbeizhai in Sichuan province, which is called the most refractory gold ores in China. It is shown that gold recovery reach 91.73% in the combined process which is described as follows: The flotation of the sulphide gold ores is under controlled conditions, producing the concentrate for pressure pretreatment with oxygen in acidic medium and the middling for the pressure pretreatment with oxygen in alkaline medium. The thickening and washing process substitute the pressure filtration process of the pulp after pressure pretreatment. The thick slimes of the two kinds of pressure pretreatment were mixed and then enter the CIL process for simplifying the flowsheet. The possible superabundance of acid of pressure pretreatment with oxygen in acidic medium was neutralized by the tailings of flotation and the cost of neutralization will be lower. The combined technology of pressure pretreatment with oxygen has the same advantages as the normal technology of pressure pretreatment and both is helpful for environment protection.

Synthesis of Ceramic Pigments ACr₂O₄Using the Non-Conventional Method of Co-Precipitation Assisted by Ultrasound and High Energy Milling

In this research ceramic pigments have been synthesized with crystalline spinel structure and chromium based with a stoichiometry ACr2O4. A was an element with +2 valence metal, in this case, metals were zinc and iron, these pigments have been synthesized by non-conventional methods like the co-precipitation assisted by ultrasound and high milling energy. Pigments were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), spectrophotometry, and colorimetric CIELab method. Results showed that it was possible to obtain a crystallin desired structure at temperatures below 900&#176C by non-conventional methods. These results showed the advantages of ceramic pigments obtained by alternative routes, because it was possible to have a better control over stoichiometry and colorimetric structure properties. Furthermore, they were obtained at temperatures lower than those used by the traditional ceramic route.

Heavy Metals Content in Water and Sediments in the Upper Litani River Basin, Lebanon

Surface water quality is largely influenced by both natural processes and anthropogenic inputs. This study involves the characterization of the concentration of heavy metals of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn, and the sources of pollution in water and sediment of the Upper Litani River Basin (ULRB) in Lebanon. The investigation was performed during three seasons of rainy, mid-rainy spring and wet periods for two years during different flow rates. Sediments were characterized by a set of chemical analyses, cation exchange capacity (CEC), mineralogy of the sediments, X-ray diffraction (XRD), and Fourier transformed infrared spectroscopy (FTIR). To assess metal contamination in sediment, Consensus-Based Sediment Quality Guidelines of Wisconsin (CBSQG) were applied. The metals contamination in the sediments was also evaluated by contamination factor (Cf). The test results showed that the effect of seasonal variations was significant in the Upper Litani River Basin. Principal Compound Analysis (PCA) and Pearson’s correlation were also performed in this study to compare and determine the correlation between metals in water and sediments. The concentrations of Pb, Cd, Cu, Cr and Zn in all sediment samples are above the norms in winter, while Fe was increased in summer. The results showed that the importance of monitoring of changes of heavy metals values and physico-chemical characterization of different parameters could represent the possibility of a comprehensive assessment of negative pressures on the water and soil ecosystem of Litani River Basin during different seasons.

Effect of Steel Slag on Soil Fertility and Plant Growth

The effective utilization of steel slag, a byproduct produced in large quantities from the steel refining process, is an important issue. Because steel slag contains abundant mineral components, the effects of steel slag on soil bacterial biomass and plant mineral uptake were analyzed in this study. The soil pH increased in proportion to the amount of steel slag added. A lower concentration (0.2% to 1%) of steel slag addition did not change the bacterial biomass. However, a higher concentration of steel slag (above 1%) had a negative effect on bacterial biomass. A lower amount of steel slag (0.2% to 1%) addition in soil leads to increased mineral (Ca, Mg, and Fe) uptake and plant growth in Brassica rapa var. periviridis and Spinacia oleracea L. However, mineral uptake by the plants decreased when a large amount of steel slag (above 1%) was added to the soil. Low concentrations of steel slag (0.2% to 1%) in soil had positive effects on plant growth, mineral uptake of plants, and bacterial biomass.

新西兰怀特岛火山热水系统构成强硫化铜金矿床的地球化学环境

新西兰怀特岛的火山热水系统与形成强硫化Cu-Au矿床的化学条件非常接近。据计算,1万多年间火山活动带出的Cu和Au(主要来自岩浆脱气)分别为1百万吨和45吨。从近期喷口中喷出的蚀变安山岩块含有明矾石、硬石膏和黄铁矿。其硫同位素组成表明,矿脉充填温度约为380℃。在此温度下,Cu、Au在酸性溶液中易于溶解。这可以解释喷发物中Cu亏损、Au缺失的原因。然而,质量平衡计算表明,Cu、Au在酸性溶液释放到地表之前就在冷却带中沉淀下来了。