滇西泸水钨锡矿床^(40)Ar-^(39)Ar法成矿年龄研究

本文采用高精度的４０Ａｒ－３９Ａｒ计时技术，系统地测定了滇西泸水钨锡矿床片麻状花岗岩、锡矿石和钨矿石中的白云母和石英等矿物的年龄，结合野外地质情况和岩矿薄片镜下特征，查明该矿为多期成矿：片麻状花岗岩年龄为１６３Ｍａ，锡矿１４５Ｍａ，钨矿有两期，分别为６９Ｍａ和３９Ｍａ。同时研制了金属超高真空碎样提氩装置，并与ＭＭ－１２００质谱计系统连接，测定了钨矿石中石英的流体包裹体的４０Ａｒ－３９Ａｒ年龄，为矿床形成年龄测定开辟了新的实验测试途径。

某钨铜矿选矿废水处理与分质回用工艺研究

对某钨铜矿选矿废水进行了“分支处理-分质回用”工艺研究。铜尾矿沉降水、铜精矿过滤水回用于铜浮选,钨精矿过滤水回用于钨精选段浮选,均满足选矿工艺用水要求;钨尾矿水经石灰絮凝、芬顿氧化工艺深度处理后可回用于磨矿及钨浮选;各股选矿废水分质回用至分系统分选工段,闭路试验可获得与清水相当的技术指标。

SAF—CTMAB法测定水中钨

利用阳离子表面活性剂的胶束分光光度法是提高钨灵敏度的有效手段。目前,在盐酸介质中采用水杨基荧光酮与溴化十六烷基三甲基铵测定钨取得较好的结果。本法是水相介质中分光光度法测定钨灵敏度最高的方法之一。

钨系水处理缓蚀剂的研究与应用

钨酸盐水处理缓蚀剂单独使用时由于使用浓度高 ,应用受到一定限制。国内外相继研制开发了以钨酸盐为主体的复配缓蚀剂。本文主要综述了钨系水处理剂的缓蚀机理研究及其应用研究情况。

新型绿色钨系水处理剂的应用研究

综述了钨系水处理剂的缓蚀机理研究及其近年来的应用研究情况。钨系水处理剂具有无毒、无污染的优点,随着人们环保意识的增强和水资源的日益短缺,其又一次受到人们的重视。随着一些新型的全有机的绿色缓蚀阻垢剂的相继开发,大大促进了绿色钨系复配药剂的发展,指出绿色钨系水处理剂会有广阔的应用前景。

白钨选矿尾水悬浮物人工湿地基质沉降模拟研究

人工湿地在运用过程中表现出对悬浮物良好的去除作用,但其去除机理和规律的研究却不够透彻。为了探究白钨选矿尾水悬浮物的去除效果及固体颗粒在人工湿地基质中的沉降规律,选择花岗岩或石英,构建水平潜流人工湿地系统,考察水力坡度对悬浮物去除效果的影响,分析沉积颗粒粒径。结果表明:人工湿地对悬浮物有良好的去除效果;6～12 mm的花岗岩作填料,水力坡度为0.25%时,去除效率在60%以上,出水中悬浮物的含量在40 mg/L左右;预处理的絮凝过程将无法沉降的2μm以下的颗粒物从63%降至20%以下,颗粒中值粒径由1.64μm扩大至3.97μm;沉积物粒径分布在3.5～23.6μm间,沉降距离可依据Stokes定律推算。

钨浮选尾矿水对白钨矿浮选影响及新工艺研究

钨浮选尾矿水因含敏感离子、残留药剂和悬浮物,对浮选过程产生不良影响。本文针对钨浮选尾矿水中常见的敏感离子,进行了敏感离子含量对白钨矿及与其共生关系密切且可浮性相近的萤石和方解石的可浮性规律研究,并开发“强化脱泥-浮选”新工艺,对含Cu 0.687%、S 21.48%、WO30.125%的原矿进行工业试验获得:铜精矿Cu品位24.00%,回收率87.65%;硫精矿S品位43.63%,回收率71.30%,磁硫精矿S品位31.36%,回收率17.16%,总硫回收率88.46%;钨粗精矿WO3品位9.05%,作业回收率80.61%、对铜硫尾矿回收率55.58%;钨精矿WO3品位66.51%,对铜硫尾矿回收率53.83%、对原矿回收率47.41%。

白钨选矿尾水石灰絮凝沉降效果初步探讨

为了利用人工湿地对白钨选矿尾水进行深度处理时不发生堵塞,选择石灰作为絮凝剂,进行了预处理试验,考察了絮凝剂用量对尾水沉降速度及污染物去除效率的影响。结果表明:随着石灰用量的增加,清液中悬浮物和重金属的含量降低,尾水的沉降速度减慢。对比清液中重金属与悬浮物的去除率,并根据原矿成分和选矿流程进一步推导,发现尾水中重金属的主要存在形式为悬浮态。综合考虑沉降速度、清液中悬浮物含量、经济效益三个因素,确定预处理过程中石灰用量为1.5kg/t尾水。

A novel dicobalt-substituted tungstoantimonate polyoxometalate: Synthesis,characterization,and photocatalytic water oxidation properties

The one-pot assembly reaction of a trilacunary,lone-pair-containing[B-α-SbW9O33]9.precursor with Co2+ions in an aqueous medium led to the isolation of a novel{SbO3(H2O)3}bridging,dicobalt-substituted,sandwich-type tungstoantimonate{Co2Sb2(H2O)10[B-β-SbW9O33]2}^4–(1a).This compound was structurally characterized in the solid state by single-crystal X-ray diffraction,elemental analyses,thermogravimetric analysis,and IR spectroscopy.The most remarkable feature was that 1a comprises two trilacunary[B-β-SbW9O33]9^-fragments trapping a novel,centrally symmetric,rhomb-like{Co2Sb2}belt with 10 terminal water molecules.When combined with the photosensitizer[Ru(bpy)3]^2+and the sacrificial electron acceptor S2O82.,1a exhibited efficient catalytic activity for water oxidation with a remarkable turnover number(TON)of 193,initial turnover frequency(TOFinitial)of 5.3 s^-1,O2 yield of 30.8%,and quantum yield(ФQY)of 36.2%under light-driven conditions.

A review on tungsten-trioxide-based photoanodes for water oxidation

Photoelectrochemical(PEC)water splitting capable of reducing and oxidizing water into hydrogen and oxygen in a generation mode of spatial separation has gained extensive popularity.In order to effectively produce hydrogen at the photocathode of a PEC cell,the photoanode,where the oxygen evolution reaction occurs,should be systematically developed on priority.In particular,WO3 has been identified as one of the most promising photoanode materials owing to its narrow band gap and high valence band position.Its practical implementation,however,is still limited by excessive electron–hole recombination and poor water oxidation kinetics.This review presents the various strategies that have been studied for enhancing the PEC water oxidation performance of WO3,such as controlling the morphology,introducing defects,constructing a heterojunction,loading a cocatalyst,and exploiting the plasmonic effect.In addition,the possible future research directions are presented.

Adsorption of copper ions on porous ceramsite prepared by diatomite and tungsten residue

In order to realize resource utilization of industrial tungsten residue and treatment of heavy metal wastewater in mining and metallurgical area of south China,a novel ceramsite was prepared with the main raw materials of diatomite and tungsten residue.The adsorption behavior of copper ions in solution on the ceramsite was investigated.Results indicated that the surface of the newly-developed ceramsite was rough and porous.There were lots of pores across the ceramsite from inner to outside.MnFe2O4 was one of the main components of the ceramsite.The Cu^2＋adsorption capacity by the ceramsite reached 9.421 mg/g with copper removal efficiency of 94.21%at 303 K,initial Cu^2＋concentration of 100 mg/L and dosage of 0.5 g after 300 min adsorption.With increase of ceramsite dosage,the total adsorption amount of Cu^2＋increased,but the adsorption capacity decreased.The adsorption capacity increased with the increase of solution p H.The isothermal adsorption of Cu^2＋by the ceramsite fitted the Freundlich model better.The adsorption mainly occurred on a heterogeneous surface,and was a favorable process.The adsorption process closely followed the pseudo-second kinetic equation.In initial stage of wastewater treatment,the adsorption process should be controlled mainly by diffusion,and the removal of Cu^2＋can be improved by enhancing agitation.

Utilization of wastewater from zeolite production in synthesis of flotation reagents

The application of waste alkali liquids as a substitute of sodium hydroxide for the saponification to improve the collection performance of fatty acids was investigated by saponification reaction test and flotation test.The results of the saponification reaction test indicated that the optimal conditions for the saponification were stirring rate of 55 r/min,initial temperature of 40℃ and stirring time of 45 min.Meanwhile,the laboratory scale and industrial scale flotation experiments showed that the fatty acid salt synthesized by wastewater achieved an index comparable to fatty acid sodium synthesized by sodium hydroxide.As a consequence,it was feasible to replace sodium hydroxide with the wastewater from zeolite production for fatty acid saponification.The cross-border utilization of waste alkali liquids not only reduced environmental pollution,but also produced excellent economic benefits.

Technogenic hydrogeochemical anomalies of tungsten deposits in Kykylbey ore region

Peculiarities of the tungsten deposits drainage flow chemical composition formation, the development of which was ceased almost 40 years ago, have been considered. Migration peculiarities of ore components have been covered, and forms of their migration have been calculated. Inertial characteristics of the surface flow contamination are shown.

An Experimental Study of Oxygen Isotope Fractionation in the Quartz-Wolframite-Water System

Oxygen isotope fractionation was experimentally studied in the quartz-wolframite-water systemf rom 200 to 420℃.The starting wolframite was synthexized in aqueous solutions of Na2WOR·2H2O+FeCl2·4H2O or MnCl2·4H2O.The starting solutions range in salinity from 0 to 10 equivalent wt.% NaCl.Experiments were conducted in a gold-lined stainless steel autoclave,with filling degrees of about 50%.The results showed no significant difference in dquilibrium isotope fractionation between water and wolframite,ferberite and huebnerite at the same temperature(310℃）.The equilibrium oxygen isotope fractionation factors of wolframite and water tend to be equal with increasing temperature above 370℃.but to increase significantly with decreasing temperature below 370℃.

Dissolving behavior of ammonium paratungstate in(NH_4)_2CO_3-NH_3?H_2O-H_2O system

The effects of temperature, ammonia concentration and ammonium carbonate concentration on the dissolving behavior of ammonium paratungstate were studied in（NH4）2CO3-NH3？H2O-H2O system. The results show that rising temperature, prolonging duration, increasing ammonia concentration and decreasing ammonium carbonate concentration favor dissolving of ammonium paratungstate at temperature below 90 ℃, while the WO3 concentration decreases after a certain time at temperature above 100 ℃. Furthermore, the undissolved tungsten exists in the form of either APT·4 H2O below 90 ℃ or pyrochlore-type tungsten trioxide above 100℃. In dissolving process, the ammonium paratungstate dissolves into paratungstate ions followed by partially converting to tungstate ion, resulting in the coexistence of the both ions. This study may provide a new idea to exploit a novel technique for manufacturing ammonium paratungstate and pyrochlore-type tungsten trioxide.

Electrocatalytic Activity of Tungsten Carbide and Natural Zeolite Composite in Aqueous Solution

Tungsten carbide and zeolite nanocomposite was prepared by combining a mechanochemical approach with a reduction and carbonization approach,using natural zeolite and ammonia metatungstate as precursors.The sample was characterized by X-ray diffraction and scanning electron microscope.The results showed that the crystal phase of the sample is composed of zeolite,monotungsten carbide and bitungsten carbide.The mass percentage and the crystallite diameter of tungsten carbide change along with the reacted time.Its electrocatalytic activity was measured with a microelectrode system with three electrodes.The results show that its electrocatalytic property is related to its crystal phase and the mass percentage of tungsten carbide,and its electrocatalytic activity is connected with the property of electrolyte,in which it is measured.Synergistic effect between tungsten carbide and zeolite is found during electrocatalysis.

Light energy conversion device for photocatalyst 2.0%WO_3-TiO_2 with oxygen vacancies for water splitting

Using carbon felt, polytetrafluoroethylene latex and powder catalyst to assembly a light energy conversion device, the photocatalytic activity of catalyst 2.0%WO3-TiO2 （2%WO3 compounding TiO2） with oxygen vacancies was studied through the water splitting for O2 evolution, using a high pressure mercury lamp as the light source and Fe^3＋ as the electron acceptor in two different devices： an ordinary photolysis device with catalyst powder suspending through a magnetic stirrer and a self-assembly light energy conversion device. The results show that after 12 h irradiation, the photocatalytic activity of 2.0%WO3-TiO2 with oxygen vacancies in the self-assembly light energy conversion device is higher than that of the ordinary photolysis device, and the amount of oxygen evolution is about 12 and 9 mmol/L respectively in these two devices. After 12 h, the rates of 02 evolution are slow in each device and the photocatalyst almost loses the photoactivity in the ordinary photolysis device. So, compared with the ordinary photocatalytic device, the rate of oxygen evolution and the life time of the catalyst are improved in the self-assembly light energy conversion device.

Recovery of Tungsten (Ⅵ) from Aqueous Solutions by Complexation-ultrafiltration Process with the Help of Polyquaternium

Polyquaternium-6 (PQ6) as the water-soluble polymer was used for complexing the anion forms of tungsten (Ⅵ) before ultrafiltration. Tungsten (Ⅵ)-PQ6 complex was retained by polysulfone hollow fiber ultrafiltration membrane in the complexation-ultrafiltration process. Effects of various operating parameters such as polymer metal ratio(PMR), pH and chloride ion concentration on permeate flux (J) and tungsten rejection coefficient (R) were investigated. The integration of four experiments including concentration, decomplexation, diafiltration and reuse of regenerated polymer was carried out. In the process of concentration, J declines slowly and R is about 1 at PMR of 3 and pH of 7. Tungsten concentration in the retentate increases linearly with volume concentration factor. Tungsten is concentrated efficiently with the membrane. The concentrated retentate was used further for the decomplexation. It takes about 6 min to reach the decomplexation equilibrium at chloride ion concentration of 50 mg·L-1 . The decomplexation percentage of tungsten (Ⅵ)-PQ6 complex reaches 56.1%. In the diafiltration process, tungsten (Ⅵ) can be extracted effectively by using 50 mg·L-1 chloride ion solution, and the purification of the regenerated PQ6 is acceptably satisfactory. The regenerated PQ6 was used to bind tungsten (Ⅵ) at various pH values. The binding capacity of the regenerated PQ6 is close to that of fresh PQ6, and the recovery percentage of binding capacity is higher than 90%.

Production of Rhenium by Transmuting Tungsten Metal in Fast Reactors with Moderator

The feasibility of rhenium （Re） production by irradiating tungsten （W） metal in a medium size fast reactor was evaluated by using a Monte Carlo code. The fast reactor can produce about 50 kilograms of Re per every 3 years, which corresponds 10% of Japanese domestic production. The specific activity of Re can be reduced below the exemption level or even the natural Re level if W and osmium is separated after the irradiation. The use of ZrD1.7 moderator reduces the specific activity by half compared to that of ZrH1.7 case, and even the no moderator case is permissible to produce the production of Re which has lower specific reactivity than that of natural Re.

Effects of sodium tungstate on properties of micro-arc coatings on magnesium alloys

Anodic coatings were prepared by micro-arc oxidation on AZ91HP magnesium alloys in a base solution containing 10 g/L NaOH and 12 g/L phytic acid with addition of 0-8 g/L sodium tungstate.The effects of sodium tungstate on the coating thickness, mass gain,surface morphology and corrosion resistance were studied by eddy current instrument,electronic scales,scanning electron microscope and immersion tester.With the addition of sodium tungstate,the electrolytic conductivity increases and the final voltage decreases.The sodium tungstate has a minor effect on the coating thickness,but lightens the coating color.With increasing sodium tungstate concentration,the size of micropores on the coatings is enlarged and the corrosion resistance of the anodized samples decreases.