Extraction Molybdenum Methods from Tungsten Molybdenum Mixture and Mixture of Molybdenum and Other Metals

This article will describes some simple methods to extract molybdenum from tungsten molybdenum mixture and mixture of molybdenum and other metals. Extracted molybdenum from tungsten molybdenum ore is research focus of molybdenum extraction, the following will simple introduce some methods of separation tungsten and molybdenum and extracting molybdenum.

1. Recovering tungsten and molybdenum from phosphorus ore: the phosphorus ore was decomposed by 2~5mol/L acid, after that, to process liquid-solid separation, thereby separating the molybdenum and tungsten.

2. Separated tungsten and molybdenum from the mixed solution of tungstate and molybdate: to adjust tungstate and molybdate mixture’s pH value, and then added the precipitating agent so that it will reacts preferentially with the tungsten to produce precipitate. After solid-liquid separation can obtain molybdate solution and rich-tungsten slag.

3. Using tungsten hydrometallurgy to separate tungsten and molybdenum from mixed ammonium salt solution of tungsten and molybdenum: the vulcanizing agent is added to tungsten and molybdenum mixed ammonium solution and after reaction be processed thiosulfate treatment.

4. Depth Separated molybdenum and tungsten from mixture solution containing high content molybdenum and tungsten: Firstly, the pH was adjusted to 6.5~8.5, and then using exchange column of alkalescence anionexchange resin exchange resin to adsorb so that it can separate tungsten and molybdenum.

Several methods of extracted molybdenum from mixture of molybdenum and other metals are as follows:

1. Recovered molybdenum form aluminium base containing molybdenum waste slag: mixing aluminium base with NaOH solution and Na2CO3 evenly and then it be sintered in rotary kiln. After that it was digested by alkaline correction liquor, solid-liquid separation to obtain a crude liquid sodium aluminate and red mud residue. Finally, using resin adsorbs molybdenum in circulating mother liquor of Bayer liquor production system, thereby recovering molybdenum.

2. Extracted molybdenum from molybdenum copper mixture: heating molybdenum copper mixture form the molten matte to molybdenum copper matte. Add bubbling air or oxygen-enriched air into copper molybdenum matte for blowing, then after collecting dust in recovering MoO3.

molybdenum extraction, tungsten molybdenum mixture, mixture of molybdenum and other metal. 

Molybdenum Extraction Methods from Nickel-molybdenum Mixture

China has rich resources of molybdenum, is the world's largest molybdenum resources in the country, including molybdenum reserves accounted for 44% of the world molybdenum reserves. At present, China is the world's largest molybdenum producer and consumer. China molybdenum supply and demand to the international molybdenum price changes have a greater impact. Development of molybdenum extraction technology can not only reflects the level of industry technology, and can provide some support for the development of the industry. In recent years, the technology of molybdenum extraction from different materials is in the development process, providing some reference and support for molybdenum industry. There will brief introduce some methods of extraction molybdenum from nickel-molybdenum mixture. Extracted from the mixture of nickel-molybdenum in molybdenum extraction technology is more mature, so the corresponding extract molybdenum patented technology is greater, which is mostly used in lixiviation process.

1. Using wet process to extract molybdenum form nickel molybdenum ore: firstly the nickel-molybdenum ore was subjected to atmospheric leaching with sodium hydroxide solution. After leaching, adding air, oxygen-enriched air or oxygen into the slurry, and then extract the molybdenum.

2. Using lixiviation process to extract nickel-molybdenum ore: using ozone or hydrogen peroxide as an oxidizing agent and using dilute sodium hydroxide or dilute hydrochloric acid as an activated media extracts nickel-molybdenum paragenic ore for leaching molybdenum.

3. Using alkaline leaching solution to extract molybdenum from nickel molybdenum ore: using Fe3+ as a precipitating agent was added to the nickel-molybdenum alkali leaching solution and adding a buffer agent to adjust the pH of the solution. The resulting precipitate containing molybdenum was desorbed by ammonia desorbed ammonium. After that we obtained molybdic acid ammonium solution.

4. Extracted molybdenum from stone coal ore containing nickel and molybdenum: to grain the ore into powder and add sodium carbonate into it. After high temperature melting, obtain a nickel-iron alloy and slag. Then using water to soak slag, obtained leaching solution containing molybdenum.

Copper Molybdenum Copper (CMC) Material

Because copper has a high electrical conductivity, thermal conductivity and molybdenum has a low coefficient of thermal expansion, high strength and other good properties, so the use of both the excellent performance of a composite material highly favored by electronics engineers. Besides, it has a wide range of applications in microelectronics. Many companies using online continuous rolling composite technology and the United States AMAX company and Climax Specialty Metals company using hot rolling complex methods to produce a copper molybdenum copper (CMC) composites material, and applied the relevant patents. In China, some researchers have tested the explosive welding method for CMC electronic packaging production and have studied the adhesion mechanism of CMC encapsulating material interface in detail. Because the physical properties of copper and molybdenum are quite different and they are not mutually solution, so the interface of both copper and molybdenum can closely combine is the key to the preparation of CMC composites material. On the one hand the interface should have high bonding strength and clean surface is an important prerequisite to achieve high strength bonding of interface. On the other hand, if surface is too smooth, it is hard to process deformation and composite strength is lower as well, so the surface state before the composite of molybdenum and copper plate interface to achieve high strength composite material has an extremely important impact.

Molybdenum zirconium hafnium carbon alloy (ZHM alloy)

Molybdenum zirconium hafnium carbon alloy (ZHM alloys) is kind of new type molybdenum alloy which is using molybdenum as matrix elements doping a certain amount of zirconium, hafnium, and carbon and production by powder metallurgy. The content of zirconium, hafnium, and carbon are as follow: zirconium content (mass fraction) is 0.4 to 0.7%; hafnium content is 1.2 to 2.1%; carbon content is 0.15 to 0.27%. Since molybdenum, zirconium, hafnium, carbon having excellent characteristics of high melting point and tensile strength, and therefore THM alloys have good high-temperature strength, low temperature ductility and workability. In addition, after the experiments found that the tensile strength of the ZHM alloy at room temperature is 40% to 50% higher than titanium zirconium molybdenum (TZM alloy). Currently, ZHM is the highest strength molybdenum alloy among other molybdenum alloys. Meanwhile, ZHM alloys compared to other molybdenum alloys have better creep resistance, higher recrystallization temperature and good weldability. Its main application is as a powder superalloy isothermal forging dies.

Molybdenum zirconium hafnium carbon alloy produced by powder metallurgy is mainly made of the production processes are as follows:

1. Mixing high-purity molybdenum powder with hydrogenated hafnium, zirconium hydride and carbon, then molds by cold isostatic pressing.

2. To sintering press-formed powder into ingots and then to forging at 1200 ℃. The amount of deformation is about 50% to 75% or higher and at the intermediate it will process hydrogen annealing for 8 hours at 1200 ℃.

ZHM alloys are still in the development stage, a different performance in the manufacturing process and heat treatment process will have a greater impact on alloy’s properties. Therefore to study better production processes of ZHM alloys is good for improving the performance of the alloy. So it can be widely applied to more areas. Many researchers predicted that ZHM alloys may become a super alloy is used in the future.

Cleaned Molybdenum Wire

Cleaned molybdenum wire is a surface clean, no graphite layer and molybdenum oxide layer molybdenum wire, which has a good high strength, conductivity, cutting speed, long life and other good properties. Cleaned molybdenum wire is usually applied in line cutting field, it usually as vacuum devices, heating elements, refractory matter of high temperature furnace and the parts for electric light source production. In addition, the cleaned molybdenum wire can also be used as a spray molybdenum wire, applied to the wear parts of the car, improving its mechanical wear.

White molybdenum wire also called clean white molybdenum wire, using electrolytic cleaning or hydrogen sintering method to clean graphite coating on molybdenum wire surface and to make the surface bright and glossy. Electrolytic cleaning cleaned molybdenum wire method: this is a cleaning method which uses conducting medium to apply voltage on molybdenum wire and to clean molybdenum wire. And the molybdenum wire will as an electrode and immerse in electrolyte. Hydrogen sintering clean white molybdenum wire method: This method is mainly cleaning metal impurities on the surface of molybdenum wire. Firstly, putting molybdenum wire in vacuum furnace, heating vacuum furnace above 1400 ℃, repeated pass hydrogen into vacuum furnace to make the amount of hydrogen in the furnace reaches 500-10,000 microns, then remove the reaction products which produces by impurities on cleaned molybdenum wire surface and hydrogen.

Cleaned molybdenum wire applications and its performance has a certain relationship between the degree of processing, for example, un-annealed cleaned molybdenum wire and annealed molybdenum wire can as rods, hooks, mandrel and the electrodes applied to different areas, but the performances of them are different, for example, annealed cleaned molybdenum wire elongation is ≤8%; straightness is ≤20 / 200, tensile strength is 1200-2200MPa. On the other hand, un-annealed cleaned molybdenum wire elongation is ≥10%; straightness is ≤ 20/200; tensile strength is 700-1500MPa. The user can select different processing levels’ white molybdenum wire according to application.

Xiamen Chinatungsten Online Manu. & Sales Corp has provided the following molybdenum wire types, such as high temperature molybdenum wire, doped molybdenum wire, straightening type molybdenum wire, high temperature cleaned molybdenum wire, straightening and doping type cleaned molybdenum wire, straightening type cleaned molybdenum wire, high temperature straightening type cleaned molybdenum wire, doped cleaned molybdenum wire and soft cleaned molybdenum wire.

Using Gas Phase Method and Solid Phase Method to Produce Nano Molybdenum Disulfide

Using gas phase method to produce nano molybdenum disulfide

Gas phase method is directly using gas or through using a various of means to change the materials into the gas, so that the materials will occurs chemical changes or physical changes, and finally condensed and growth in the cooling process forming nanoparticles. Gas phase method has simple process, quick response and other advantages, but it has higher reaction equipment requirements and the products purity is not high which produce by gas phase method. In the gas phase methods the chemical vapor deposition (CVD) process is the most simple. The reaction process of CVD without filtration, drying and other processes, and no waste water discharge, waste gas easily recovered and other advantages, so it is widely used in industrial fields.

There will introduce two simple methods of gas phase method for nano molybdenum disulfide production:

1.Using molybdenum trioxide (MoO3) and sulfur as raw material, after mixing, at high temperature put the mixed powder into tube furnace then it will occurs gas phase reaction and to produce molybdenum disulfide (MoS2) nanotubes. The experiment found that the reaction temperature, air flow rate has some impact on the products. When the reaction temperature is 810 ~ 905 ℃ can to generate MoS3 nanotubes, and when the air flow rate at unsuitable conditions, it is possible to generate MoS2 or MoO2-xSx.

2.Putting the MoO3 into tube furnace heat to 850 ℃, then pass into H2S + (H2 + N2) [φ (H2) = 5%, φ (N2) = 95%] reducing gas, and finally in a reducing atmosphere MoO3 and H2S react to produce fullerene nanoparticles and nanotubes.

Using solid phase method to produce nano molybdenum disulfide

Solid phase method is a raw material by physical or chemical processes for preparing nanometer molybdenum disulfide in the solid state. Solid phase method generally does not destroy the crystal structure of molybdenum disulfide, and simple operation, high conversion rate, low pollution and it can avoid the agglomeration phenomenon which appears in liquid phase method. However, the solid phase method has high equipment requires and high energy consumption, while products are difficult to control particle size and shape and other shortcomings. So it is difficult to be widely used in industry.

There will introduce two simple methods of gas phase method for nano molybdenum disulfide:

1.The MoS2 and I2 powder was placed in a quartz tube heating at the high-end, maintaining a certain temperature gradient, the quartz tube to maintain a certain degree of vacuum, after dozens of days, resulting in the low-end of the quartz tube to produce MoS2 nano and microtubes.

2. Using supersonic jet mill machine to pulverize MoS2 powder obtain nanometer molybdenum disulfide.

TZM Alloy Welding by TIG

TZM alloy because of its good high-temperature properties are widely used in high temperature mold industry, aerospace, industrial machinery and other industries. TZM alloy as a structural material used in these areas typically require the desired shape and configuration which can achieved by welding skills. The experiment found that, in order to prevent TZM oxidation or inhaled nitrogen and other impurities in the welding process, a better method is TIG welding. Using TIG welding, it can make TZM alloy during welding process protect by inert gas (argon) to cut off the air and to prevent oxidation or nitrogen elements intrusion. The experiment found that the optimum welding parameters are as follows: welding speed 4mm / s; argon gas flow: 10L / min; welding current: 210A.

TZM alloy after TIG welding to do seam X-ray inspection found that when the welding current is 210A, the weld is flat and there is no holes and cracks on TZM surface, smooth appearance on the alloy. Observing the microstructure of welded joint found, the weld zone has coarse grains and there are some small holes, but weld microstructure is dense and no cracks. On the other hand, TZM alloy coarse grained zone and the transition zone affected by the heat of the welding process to virtually eliminate the original structure and to formed a relatively coarse equiaxed crystalline, while the original base material still maintaining crystalline sheet organizational structure. Observing its tensile strength found that the average tensile strength of welding is significantly less than the original base material. The increase of the elongation of the alloy is due to the thermal effect of the welding process to eliminate the portion of fiber texture which is formed by rolling, so that the edge of the weld is "softening." Observing the tensile fracture of TZM alloy after welding found the welding coarse grained area is not lamellar crystals, but still showing intergranular brittle fracture morphology. Coarse equiaxed grain replaced lamellar crystals, thus the weak strength of the material, but at some certain extent, improving the plastic of material can basically meet the requirements of ordinary structural.

TZM alloy Deoxidation Mechanism Analysis during Vacuum Sintering

The experiment found that TZM alloy during powder metallurgy sintering process mainly has two kinds of deoxidation mechanisms: the first one, metal oxide of carbon reduction system to form metal carbides and CO; the second one, MoO2 happening disproportionation reaction at vacuum high temperature to form metal Mo and MoO3 gas, where the MoO3 gas will be discharged by vacuum system.

Firstly, analysis the influence of carbon content on TZM alloy deoxidation during vacuum sintering. Experiment arrangement as follows: adding 0.5% TiHx and 0.09% ZrHx into molybdenum powder, and then dividing the sample into three parts, in the sample were added 0.04%, 0.07%, 0.10% different proportions of carbon, and finally made TZM alloy rods. Tested oxygen content and the carbon content of TZM alloy bar found C element content and TZM alloy deoxidation effect is proportional to, but excess carbon can cause alloy component failure.

In addition, the oxygenium of molybdenum mixed powder mainly decisions by oxygen content of molybdenum powder. Molybdenum powder after the reduction reaction, the mainly existing way of oxygen is molybdenum oxide, which the most stable is MoO3 and MoO2, and MoO3 in a vacuum and high temperature will volatilize into a gas, so at high temperature molybdenum oxide mainly exists by MoO2 form. The experiment found that in the case of high temperatures and the absence of air, MoO2 happen disproportionation reaction to produce metal Mo and gaseous MoO3, and gaseous MoO3 will be discharged by vacuum system.

TZM alloy deoxygenation process mainly achieved by carbon reaction and disproportionation reaction of MoO2 which occurs in high-temperature vacuum sintering process. The reaction temperature and air pressure of product in vacuum furnace will have great impact on the quality of these two reactions. Reducing the partial pressure of product and improving vacuum degree can reduce the deoxygenation reaction temperature of the beginning which is good for reducing oxygen content of TZM alloy.