Adhesion between nanobubbles and fine cassiterite particles

Adhesion is an important process of particle-bubble interaction in fine particle(-10μm)flotation.This paper studied the adhesion process and mechanism between nanobubbles and fine cassiterite particles by using a high-speed camera,atomic force microscope(AFM),adsorption capacity tests,and induction time tests.After being pretreated with nanobubbles(NBs)water,fine cassiterite particles flotation tests were carried out using caprylhydroxamic acid(CHA)as a collector.The results showed that NBs can improve the recovery and flotation rate of fine cassiterite while decreasing the collector dosage.The adsorption capacity test indicated that the cassiterite treated with NBs had lower demand for collector concentration.The AFM imaging results further demonstrate that NBs could reduce the adsorption of CHA on the surface of minerals.Since NBs played a part of the role of collector,it can improve the flotation effect while reducing the amount of collector.The induction time test and the high-speed camera observation test showed that NBs promoted the attachment between bubbles and cassiterite particles.On the other hand,NBs agglomerate cassiterite particles,increasing the probability of particles colliding with bubbles.

Influence of metal cations on cassiterite flotation

Flotation of cassiterite has been studied on pure minerals performed in a microflotation cell with various collectors. The results indicate that sulphosuccinamate demonstrates strong collection, good selectivity on cassiterite in the region around pH 6, and that lead ions have certain activation whereas other ions such as ferric, aluminum, manganese, ferrous, calcium have strong depression on cassiterite flotation. In addition, X ray photoelectron spectroscopy (XPS) was applied to study the flotation systems of cassiterite sulphosuccinamate in the presence and absence of metal cation, and a chemisorption mechanism through chemically bonding between stannum species on the cassiterite surface and oxygen from sulphosuccinamate is proposed. The chemical environment of stannum species would be changed in the presence of lead ions in the flotation systems and therefore improve the activity of the stannum species, while ferric ions show strong depression due to the formation of steady complexes between ferric species and collector.

Cassiterite U-Pb Date of the Yangbin Porphyry Tin Deposit in Zhejiang and its Geological Significance

Objective The Yangbin porphyry tin deposit in Taishun County of Zhejiang Province is one of the few porphyry-type tin deposits in South China, which is located in the middle portion of the Mesozoic volcanic active belt on the southeastern coast of China. The Yangbin granite porphyry is closely related to the tin mineralization in this region. Based on petrologic and Sr-Nd-Pb isotopic

The Effects of Blends of Enugu Coal and Anthracite on Tin Smelting Using Nigerian Dogo Na Hauwa Cassiterite

The effects of blending Enugu coal and anthracite on tin smelting using Nigerian Dogo Na Hauwa cassiterite have been studied. The work utilized various blends ranging from 100% to 0% anthracite. The content of the Enugu coal in the blend varied from 5% to 100%. The various tin metal recovery percentage for each batch of smelting using various blends was noted. Anthracite alone had the highest recovery of 71.90% followed by 5% blend of Enugu with anthracite. The result, however, showed that as the Enugu Coal was increased in the blend, the recovery was also decreasing. This equally affected the quality of tin metal recovered by increasing the grade. The work recommended that since the cost of production is the critical issue, 5% - 15% range of Enugu Coal should be used in preparing blends to bring down the cost of imported anthracite which is put at $906.69 per ton. The use of 15% Enugu coal will result in lowering the cost of imported anthracite by $136.0.

Model for Prediction of the Concentration of Extracted Tin during Leaching of Cassiterite in Potassium Hydroxide Solution

Model for prediction of the concentration of tin extracted during potassium hydroxide leaching of cassiterite has been derived. The model: A = Nt1.53, indicates that the concentration tin extracted is dependent on the residence time. It was found that the validity of the model is rooted in the expression Log A = Log (Nt1.53). Tin extraction per unit time as obtained from experiment and derived model are 2.6666 and 2.6268 mg/min respectively. The maximum deviation of the model-predicted concentration of dissolved tin from the corresponding concentration obtained from the experiment was found to be less than 8%, which is quite within the acceptable deviation limit of experimental results and hence, impacting about 92% confidence coefficient on the model.

Mineralogical Characterization of Kuru Cassiterite Ore by SEM-EDS,XRD and ICP Techniques

The morphology and elemental characteristics of Kuru Cassiterite ore deposit was performed by the combination of different instruments. This is vital to obtain accurate mineralogical, surface properties and compositions of the ore. Mineral particles were prepared on epoxy resin, polished and analyzed by a SEM coupled with an EDS. X- ray diffraction showed that the ore contained different minerals of cassiterite, coffinite, siderophyllite,ilmenite, qartz, rutile, manganocolumbite, zircon, tilleyite and monazite. Further quantitative analysis using inductive coupled plasma – optical emission spectrometry gave the elemental analysis as follows;Sn (28.0%), Si (5.5%), Fe (5.16%),Ti (3.51%), Al (2.48%), Y (1.06%), and Nb (2.53%). The other trace elements found include Mn, K, Na, Mg, La, Ce, U and Ca. The ICP-OES data was correlated with the XRD data obtained using the Guassian Pro 8.1 origin software and it showed significant correlation.

Study the Critical Role of Admixtures in Cement Production: The Optimum State of Cassiterite (SnO₂) Addition as a Natural Mineralizer-Oxide Influencing the Cement Properties

In this work we evaluate the role of a natural mineralizer-oxide like cassiterite (SnO2) on the cement properties. In particular, we study the effect of different quantities of SnO2 with 0.5, 1.0, 1.5 and 2.0 wt% on burnability of industrial raw mix by free lime evaluation. We obtain four datasets, with successive increase of temperature at 1250℃, 1350℃, 1400℃ and 1450℃. We study the produced cassiterite-added clinker with X-ray diffraction (XRD), thermal analysis (DTA) and scanning electron microscopy (SEM). Though, we characterize the new phases formed and whether, adding excess SnO2 is promote forms of C3S, C2S influencing the final quality of cement.

Recovery of Cassiterite and Topaz Minerals from an Old Metallurgical Dump, Eastern Desert of Egypt

Huge amounts of tailing dumps as a result of mines’ blasting operations were impacting economic and environmental problems. Evaluation of one of these tailing dumps of the Eastern Desert of Egypt showed the presence of reasonable amount of cassiterite mineral reaching 0.199% SnO2. The mineral cassiterite was found as finely disseminated particulates, reached to 5 microns, within varieties of quartz-feldspar-hornblende-biotite granitic formations. In the present study, the processing regime considered from the beginning the alignment between reaching cassiterite mineral liberation size, and its extreme brittleness character. Stirring ball milling technique was applied to produce −0.51 mm product with minimum fines as possible, which was left aside for a separate study. The ground product −0.51 + 0.074 mm was subjected to joint shaking table/dry high intensity magnetic separation techniques after splitting it into two fractions, −0.51 + 0.21 mm and −0.21 + 0.074 mm. Each fraction was separately subjected to “Wilfley” shaking table. At optimum conditions, a shaking table concentrate was obtained with 0.29% SnO2 and an operational recovery reached 96.94% from a feeding contained 0.19% SnO2. The heavies and the two middling products after shaking table were directed separately after dryness to dry high intensity magnetic separation using “Eriez” rare earth roll separator, meanwhile the light fractions were rejected. Mathematically designed experiments were applied to optimize the separation process. At optimum conditions, a final cassiterite concentrate was obtained with 11.25% SnO2, and an operational recovery 94.08%. In addition, a topaz mineral concentrate was separated at splitter angle 65˚.

Tin transport and cassiterite precipitation from hydrothermal fluids

Cassiterite(SnO_(2))is the main ore mineral of tin in magmatic-hydrothermal tin deposits,but tin transport and precipitation mechanisms from hydrothermal fluids remain poorly understood.We critically evalu-ated aqueous tin speciation in hydrothermal fluids from extensive experimental data and thermody-namic modeling.Sn(II)chloride complexes in hydrothermal fluids exist mainly as SnCl^(+),SnCl_(2)(aq),and SnCl_(3).The revised Helgeson-Kirkham-Flowers model parameters of these three tin species and two tin ions(Sn^(4+) and Sn^(2+))were derived from the correlation algorithms among these parameters,and the standard molar properties of cassiterite were optimized to be internally consistent with the available thermodynamic dataset.These thermodynamic parameters,together with the available equilibrium con-stant equation of Sn(IV)chloride complexes,could reproduce the available solubility data of cassiterite in acidic solutions at 400-700℃under oxygen fugacity(f_(o2))levels buffered by hematite-magnetite(HM)or nickel-nickel oxide(NNO).These comparisons allow modeling chemical systems of SnO_(2)-NaCl-HCI-H_(2)O(liquid phase)to examine tin transport and cassiterite precipitation mechanisms under tin-mineralizing conditions:300--500℃,50-150 MPa,2 molal NaCI,and fo。levels from QFM(quartz-fayalite-magnetite)to HM.Sn(I)chloride complexes are commonly interpreted to dominate in aqueous tin speciation under f_(o2)=NNO,but our modeling results indicate that considerable contents of Sn(IV)chloride complexes also exist in those reduced fluids with high HCI contents,consistent with recent in situ high-temperature experiments and molecular dynamic simulations.The Sn(I)/Sn(IV)ratios in fluids depends onfo,temperature,and HCl contents.A considerable amount of Sn(IV)possibly exist in an early mineralization stage even under f_(o2)=NNO;if so,redox reactions are unnecessary to precipitate cassiterite from these mineralizing fluids.We find that even if the f_(o2) levels are constant,simple cooling can alter mineralizing fluids to be more oxidized(e.g.,from QFM to HM)and cause cassiterite precipitation,indicating that oxidizing agents are not necessary as previously thought.This explains why cassiterite can precipitate in host rocks(e.g.,sandstone or quartzite)that do not provide oxidizing agents.A simple rise in f_(o2),levels and pH neutralization(e.g.,greisenization)also cause cassiterite precipitation.Cassiterite solubility in oxidized acidic hydrothermal fluids(NNO<f_(o2),<HM)is high enough to account for the tin contents of fluid inclusions from typical tin deposits,but the mineralization potential of oxdized fluids is inferior to reduced fluids(f_(o2),≤NNO)under the same conditions.

Mineralization of the Lianhuashan Sn-polymetallic deposits associated with dynamic metamorphism:Constraints from cassiterite geochemistry and U-Pb geochronology

The Lianhuashan metallogenic belt in Eastern Guangdong Province(South China)is the most important Sn polymetallic district in the region,hosting many medium-sized deposits such as the Tashan,Xianshuili,and Jiangxikeng.However,the metallogenic mechanism of these deposits remains hotly debated.In this paper,two types of cassiterites(Cst1 and Cst2)have been identified in the Xianshuili and Jiangxikeng Sn deposits,which are hosted in the biotite-mylonite and garnetcordierite-muscovite blastomylonite,respectively.The euhedral Cst1(0.50–1.8 mm)coexists with biotite,feldspar,and quartz.It is platy and zoned with a mosaic structure.The subhedral to anhedral Cst2(0.02–0.35 mm)coexists with metamorphic minerals such as garnet and cordierite,and it is characterized by well-developed porosity and has no zonation.In-situ U-Pb dating of the Cst1 and Cst2 yielded ages of 149.5±1.0 Ma(MSWD=1.6,n=45)and 125.1±2.3 Ma(MSWD=4.5,n=43),respectively.Cst1 is most likely to be related to the intermediate-felsic magmatism that formed Gaojiping Group,whereas Cst2 has relatively high Ta,Nb,Fe,and W contents with obvious rare earth tetragroup effect,and may have formed by the late Early Cretaceous dynamic metamorphism.Results presented here,when combined with regional geology and geochemistry,led us to suggest that the Mesozoic intermediate-felsic volcanic rocks in the LMB are significantly enriched in Sn and F,with high Sn-polymetallic mineralization potential which likely have contributed to the volcanic-related Cst1.In the late Early Cretaceous period,due to the NW-dipping subduction of the paleo-Pacific plate,the intermediate-felsic volcanic rocks underwent dynamic metamorphism that led to Sn mobilization,migration,and precipitation in the regional ductile shear zones,and eventually generating Sn mineralization.We propose that areas beneath Xianshuili and Jiangxikeng have great potential for discovery of new Sn resources.Our findings likely offer practical importance to regional geological ore prospecting.

Testing the robustness of particle-based separation models for the magnetic separation of a complex skarn ore

Physical separation processes are best understood in terms of the behaviour of individual ore particles.Yet,while different empirical particle-based separation modelling approaches have been developed,their predictive performance has never been tested under variable process conditions.Here,we investigated the predictive performance of a state-of-the-art particle-based separation model under variable feed composition for a laboratory-scale magnetic separation of a skarn ore.Two scenarios were investigated:one in which the mass flow of the different processing streams could be measured and one in which it had to be estimated from data.In both scenarios,the predictive models were sufficiently general to predict the process outcomes of new samples of variable composition.Nevertheless,the scenario in which mass flow could be measured was4%more precise in predicting mass balances.The process behaviour of minerals present at concentrations above 0.1%by weight could be accurately predicted.Our findings indicate the potential use of this method to minimize the costs of metallurgical testwork while providing in-depth understanding of the recovery behaviour of individual ore particles.Moreover,the method may be used to establish powerful tools to forecast mineral recoveries for partly new ore types at a running mining operation.

Geochronology and geochemistry of the Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit(73240 t) in Heilongjiang Province, China

The Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit(20000 t Sn at 0.27%,236 t Ag at 122.89 g/t,15000 t Pb at 0.84%,and 38000 t Zn at 1.43%)is located in the Wandashan Terrane of the easternmost segment of the Central Asian Orogenic Belt.The timing of Sn-Pb-Zn-Ag polymetallic mineralization remains unclear due to a lack of precise isotope dating directly conducted on ore minerals.The authors herein report that the LA-ICP-MS U-Pb ages of cassiterite and zircon from the granite porphyry in the Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit are 101.4±7.9 Ma and 115.4±1.0 Ma,respectively,indicating that Sn mineralization and magmatism occurred during the Early Cretaceous.The granite porphyry belongs to the subalkaline series peraluminous I-type granites that are depleted in Nb,Ta,and Ti and enriched in Rb,Th,U,and Pb.TheεHf(t)values of the granite porphyry range from 0.9 to 7.4,with an average of about 5.6 and two-stage model ages(T_(DM2))of 705–1116 Ma,with an average age of 819 Ma.The ε_(Nd)(t)values of the apatites are–1.60–0.45,with an average of–0.9,and two-stage model ages(T_(DM2))of 872–1040 Ma,with an average age of 983 Ma.The Nd-Hf isotope data indicate that the magma may have been derived from the partial melting of juvenile crustal material.

The giant tin polymetallic mineralization in southwest China:Integrated geochemical and isotopic constraints and implications for Cretaceous tectonomagmatic event

The Gejiu-Bozushan-Laojunshan W-Sn polymetallic metallogenic belt(GBLB)in southeast Yunnan Province is an important part of the southwestern Yangtze Block in South China.Tin polymetallic mineralization in this belt includes the Niusipo,Malage,Songshujiao,Laochang and Kafang ore fields in the Gejiu area which are spatially and temporally associated with the Kafang-Laochang and Songshujiao granite plutons.These granites are characterized by variable A/CNK values(mostly>1.1,except for two samples with 1.09),high contents of SiO2(74.38-76.84 wt.%)and Al2 O3(12.46-14.05 wt.%)and variable CaO/Na2 O ratios(0.2-0.65)as well as high zirconδ18O values(7.74‰-9.86‰),indicative of S-type affinities.These rocks are depleted in Rb,Th,U,Ti,LREE[(La/Yb)N=1.4-20.51],Ba,Nb,Sr,and Ti and display strong negative Eu and Ba anomalies.The rocks possess high Rb/Sr and Rb/Ba ratios,relatively low initial 87Sr/86Sr ratios(0.6917-0.7101),and less radiogenicεNd(t)values(-8.0 to-9.1).The zircon grains from these rocks show negativeεHf(t)values in the range of-3.7 to-9.9 with mean TDM2(Nd)and TDM2(Hf)values of 1.57 Ga and 1.55 Ga.They show initial 207Pb/204Pb ranging from15.69 to 15.71 and 206Pb/204Pb from 18.36 to 18.70.Monazite from Songshujiao granites exhibits higher U and lower Th/U ratios,lowerδ18O values and higherεHf(t)values than those of the zircon grains in the KafangLaochang granites.The geochemical and isotopic features indicate that the Laochang-Kafang granites originated by partial melting of Mesoproterozoic crustal components including biotite-rich metapelite and metagraywacke,whereas the Songshujiao granites were derived from Mesoproterozoic muscovite-rich metapelite crustal source.Most zircon grains from the Songshujiao,Laochang and Kafang granites have high-U concentrations and their SIMS U-Pb ages show age scatter from 81.6 Ma to 88.6 Ma,80.7 Ma to 86.1 Ma and 82.3 Ma to 87.0 Ma,suggesting formation earlier than the monazite and cassiterite.Monazite SIMS U-Pb ages and Th-Pb ages of three same granite samples are consistent and show yielded 206 Pb/238U ages of 83.7±0.6 Ma,83.7±0.6 Ma,and 83.4±0.6 Ma,and 208Pb/232Th ages of 83.2±0.5 Ma,83.8±0.4 Ma,and 83.5±0.9 Ma,which are within the range of the SIMS zircon U-Pb ages from these rocks.The data constrain the crystallization of the granites at ca.83 Ma.In situ U-Pb dating of two cassiterite samples from the cassiterite-sulfide ore in the Songshujiao ore field and Kafang ore field,and two from the cassiterite-oxide+cassiterite bearing dolomite in the Laochang ore field yielded weighted mean 206 Pb/238U ages of 83.5±0.4 Ma(MSWD=0.6),83.5±0.4 Ma(MSWD=0.5),83.6±0.4 Ma(MSWD=0.6)and 83.2±0.7 Ma(MSWD=0.6),respectively.Combined with geological characteristics,the new geochronological data indicate that the formation of the granites and Sn polymetallic deposits are coeval.We correlate the magmatic and metallogenic event with lithospheric thinning and asthenosphere upwelling in continental extension setting in relation to the eastward subduction of the Neo-Tethys beneath the Sanjiang tectonic domain during Late Cretaceous.

Role of Magmatism and Related-Exsolved Fluids during Ta-Nb-Sn Concentration in the Central Eastern Desert of Egypt:Evidences from Mineral Chemistry and Fluid Inclusions

The rare metals of Abu Dabbab area in the Central Eastern Desert of Egypt have been investigated for their mineralogy and conditions of precipitation using combination of EMPA and fluid inclusions studies,in order to delineate the source,mechanism of formation and evolutionary model for these economic metals.The(Ta-Nb-Sn)-bearing minerals at the Abu Dabbab area include columbite group minerals(CGMs),wodginite and cassiterite.In both granitic intrusion and its enclosed quartz veins,most of zoned CGMs and cassiterite grains are commonly characterized by a well-developed twostage texture.Hence,columbite-(Mn)(CGM-Ⅰ)represents the early formed phase of CGMs that is characterized by high Mn#values(0.64-0.92)with quite low Ta#values(0.13-0.49).It was invaded by Ta-rich phases including tantalite-(Mn)(CGM-Ⅱ;Ta#=0.13-0.49)and wodginite,which contain high Ta_(2)O_(5)and SnO_(2)(17.91 wt.%).In regard to cassiterite,there are distinct compositional differences between the early-phase cassiterite(Cst-Ⅰ)and the late-phase one(Cst-Ⅱ),where the latter is enriched in Ta_(2)O_(5),Nb_(2)O_(5)and FeO.The chemistry and textural criteria of the early stage CGM-Ⅰand Cst-Ⅰ,all are indicative of magmatic origin.While,the latter CGM-Ⅱ,wodginite and Cst-Ⅱwere influenced by the late magmatic Ta-rich fluids.Fluid inclusions microthermometry shows criteria of phase separation represented by both boiling and fluid immiscibility.The initial fluid was supposed to be of magmatic origin(magmatic CH4),that was consequently influenced by fluid mixing/dilution with post-hydrothermal/meteoric water with respect to the decompression process during uplift.Isochore construction gave rise to an estimate P-T conditions(T=330-370℃,P=22-50 MPa).The fluid inclusions’microthermometry supports a transition between magmatic and late to post-hydrothermal activities in addition to surface-derived fluid(meteoric fluid?)in a part as main source for the polymetallic deposits.

Origin of Li-F-rich granite: Evidence from high P-T experiments

Though magmatic origin of Li-F-rich granite has been supported effectively by the existence of volcanic and subvolcanic rocks and melt inclusions trapped in them with similar chemical compositions, evidence from high T-P experiments is poor up to now. To simulate the evolution process of Li-F-rich granite and to interpret its forming mechanism, a series of melting- crystallization experiments were carried out. Under the conditions of 1108 Pa and 570—700℃, a magmatic mineral association of quartz + alkali feldspar + lithium muscovite/ferromuscovite ?fluorite cassiterite is found in leucogranite-HF-H2O system. This indicates the following points: (i) Fluorite, light-colored muscovite and cassiterite can crystallize directly from the Li-F-rich gran-itic melt. (ii) The coexistence of dark-colored micas (e.g. biotite) and light-colored micas (e.g. lithium muscovite and ferromuscovite) suggests that the muscovite granite and two-mica granite can be formed under magmatic condition. The zonal texture of micas is not the sole feature for the micas of hydrothermal origin. (iii) As crystallization proceeds, the SiO2 concentration of the residual melt decreases, while the Al2O3 and F concentrations and A/CNK, NKA/Si ratios of the melt incerese, favoring the formation of Li-F-rich granites. Our experiment results are well con-sistent with the vertical zonation widely observed in rare metal bearing granites, and therefore provide strong experimental evidence for magmatic origin of Li-F-rich granite.

DISCOVERY OF PALEOPLACER TIN FROM NANTUO FORMATION OF MIDDLE SINIAN IN NORTHERN JIANGXI PROVINCE AND DISCUSSION OF ITS GEOLOGICAL SIGNIFICANCE

In 1984, the authors carried on a geological survey around Jianfengpo tin field which is bounded within gravel-bearing sandstone of Nantuo Formation of the Middle Sinian and discovered some rounded fossil cassiterites deposited both in the wall rock and in the orebody. This discovery is of important significance for revealing genesis of the deposit and taking further steps to look for ore deposit in the area in ques-tion.