tungsten rod sharpener,coolant hole carbide rods,Tungsten Carbide

Tungsten Slime Recycle – Tabling Method

Tungsten ore is fragile, during beneficiation process, tungsten slime is easily formed. So tungsten tailings still contain many effective tungsten metal elements. According to statistics, tungsten metal in slime usually accounts for 11%~14% of original ore. 

Therefore, tungsten slime recycle can improve resource application rate and lower cost. So tungsten slime is often dealt with separate process.

Tabling method is a tungsten slime processing method in early times in China. It uses single table to process concentrated tungsten slime, the main process is sieving. To promote grade of concentrate recycled from tungsten slime, many mines tungsten carbide inserts will sieve it for several times. However, the maximum recycle rate is only 35% and can not be improved any more. for tungsten slime less than 37um, it is too fine for tabling.

Although there are many shortcomings of tabling method, we can not abandon it completely. In those years when technology were backward, the simple and stable recycle method was mainly applied by enterprises. Although the recycle rate is only 35%, 27%~35% are stable. Furthermore, progress of any method is made through practice, from simple to complex. Tabling method is outdated today, but has indelible historic impact.

What’s Halide Ammonium Tungstate

Halide tungstate, the new type of visible light responsive photocatalyst, is a kind of tungstate which is mainly composed of halogen oxygen compounds.

The luminous intensity of barium tungstate is much weaker than that of other alkaline earth metal tungstate, so people try to modify the structure of barium tungstate. In 1982, Domesle synthesized fluorinated barium tungstate by using BaF₂ and WO₃ as raw materials. Ba₂WO₃F₄ is a kind of halogen tungstate, which has strong fluorescence intensity. With its strong blue-green luminescence under ultraviolet excitation, it can be developed as a practical UV and X ray luminescent material.

It is also found that rare earth tungsten composite halides can be produced with stronger luminescence properties by the preparation of halogen tungstate. LaWO₄Cl, for example, has a strong absorption of X light, of which the absorption wavelength is just within the useful range of medicine. So it is suitable for X light absorption materials. At the same time, some rare earth ions show special spectral properties. Pure La₃WO₆Cl₃, for example, the weakly Steel Inserts luminescent chemical compound will emit a very strong fluorescence after doping with Eu³⁺ and Tb³⁺.

To sum up, the main qpplication of halogen tungstate catalyst is to make X ray machine. Although it has great potential for application, there are some disadvantages. For example, its most light quantum efficiency is not high, its catalytic capacity in the visible region is very low and it is easy to deactive. The best way is to find the appropriate carrier and immobilization method. Solving the shortcomings of suspension phase photocatalyst such as easy to agglomerate and difficult to recover need the carrier. Moreover, the photocatalytic activity of the photocatalyst can be enhanced by the synergistic action of the carrier.

Tungsten Carbide Guide Bushing and Pin

Tungsten carbide guide bushing is also called drill bushing or mold bushing, which usually used with guide pin together and plays an important role in fixing and guiding. The general clearance is small, less than 0.05mm, more used in mold or some machines to ensure the cutting or drilling accuracy. Compared with bearing steel, tungsten carbide guide pin has better performance in guiding, durability and commutativity. It plays an important role in ensuring the accurate position and mold guiding. There are some funtion of tungsten carbide guide bushing and pin:
1. Connect the upper and lower guide device;
2. Maintain the clearance to reduce the bad effect of punching;
3. Endure lateral force to avoid the deviation, chipping and equipment damage or even personal safety;
4. Keep the accuracy and extend the service life by reasonable design.

According to  different applications, it can be divided into automotive mold guide pin, independent guide pin, mold milling inserts with guide post, stripper plate with guide pin; according to guiding direction, it can be divided into sliding guide pin (SGP), Rolling guide pin (SRP); and it can be divided into handling type and pressing type according to  installation mode.In addition, it should be noticed that:
1. Before processing, it is necessary to check the diameter of bottom hole and determine the dimensions of boring bar and holes;
2. Choose the proper boring bar according to the depth of hole and the terrain or position;
3. Check the eccentricity to determine whether it can completer the processing;
4. The diameter of non-working part should be 5mm longer than the corresponding guide pin;
5. After the processing, measure the aperture and verticality according to the relevant standards.
6. Based on the allowable deflection and the lateral force determine the size of the guide pin
7. Based on the variation of the clearance and the arrangement of pin and bushing;
8. Based on the minimum clearance between guide pin and bushing determine the geometric tolerance.

Hollow Ball Tungsten Trioxide Photocatalyst

Tungsten trioxide has been researched a lot, because of its unique physical and chemical properties, such as electrochromic, gas properties, photoluminescence. In addition, the tungsten oxide has non-toxic, and narrow band gap (2.4eV ~ 2.8eV), as a semiconductor material used in the visible light photocatalyst catalytic reactions of organic matter in sewage catalytic degradation. Hollow structural material has both inner and outer surfaces, and can take advantage of multiple reflections of light into the interior, which has a unique application.

 

Studies have shown that tungsten trioxide hollow ball prepared at lower temperature has the advantages not only improve utilization of light sources of catalyst, but also reduced the cost of catalyst. The method for preparing tungsten oxide hollow balls is as follows:

1. Weigh the appropriate amount of curing polystyrene microspheres, and then ultrasonic disperse it in anhydrous ethanol to form a colloidal solution;

2. Weigh the appropriate amount of tungsten hexachloride (WCl₆), then add into the colloidal solution obtained in Step 1, then the turns from white to yellow;

3. After the WCl₆ completely dissolved, slowly add the appropriate amount of deionized water, then the solution turns dark blue;

4. Place the system in a water bath at 70 ° C for stirring mechanically Deep Hole Drilling Inserts for 24 hours, cool down to the room temperature;

5. Centrifuged and washed several times with deionized water, then dried in 60°C, then placed in a muffle furnace for a heat treatment, wherein the heat treatment process: first calcined at 200 ° C for one hour, so that to completely decompose the sulfur polystyrene microspheres, and then calcined at 300°C for 3 hours, and finally we get hollow ball tungsten trioxide photocatalyst (Microscopic observation that the surface is roughness, an has portion of tungsten oxide hydrate).

Noted: the mass ratio of vulcanization polystyrene microspheres and WCl₆is 1: 2; and the volume ratio of anhydrous ethanol which is added and deionized water is 4: 1; and mass of WCl₆(g) and ratio of anhydrous ethanol (mL) is 1: 100.

 

Testing showed that the prepared hollow balls tungsten trioxide as photocatalyst, the photocatalytic degradation rate of Rhodamine B (RhB) can reach 86.61% (after 60 minutes of illumination).

Tungsten Copper Used for Vacuum High

Tungsten copper composite materials have widely used in electrical contacts, high voltage switches and breakers, especially in high voltage SF6, air / oil medium, large current circuit breaker. Recent years, with the rapid development of vacuum high-voltage switch, the contact materials have some innovation correspondly. Compared with other contacts, vacuum contact materials have higher requirements. Except the normal properties of switches, due to the surface of contact is particular clean, which will be easier welded in the air. So based on high resistance to weld, it also needs higher welding resistance, higher anti-electric erosion, low cut-off current and low content of gas. And tungsten copper excellent properties can perfectly meet the needs of high-voltage switch contacts.

From compression molding, for tungsten copper sheet contacts, CIP (Cold Isostatic Pressing) has good forming performance, but it has higher equipment investment and lower material utilization. carbide cutting tools The mechanical molding should be noted that the gap of molding tools and tungsten powder granularity. The smaller gap will cause the difficulties in stripping; the larger gap will make tungsten powder scratch the mold and produce the cracks on the surface of compact. From sintering process, porous tungsten skeleton sintered is the key process of tungsten copper manufacturing. High-temperature sintering is easy to remove impurities and ensure the electrical conductivity and the gas content meet the requirements. In addition, during the sintering process also need to consider the tungsten powder particle size, size distribution and pressing density. Too low temperature will increase the porosity and reduce the density and hardness of products; too high temperature will reduce the content of Cu and the electrical conductivity decrease. Overall, choose pure tungsten powder as raw material, mechanical molding, sintering furnace hydrogen reduction, hydrogen protection copper infiltration process to produce high-pressure vacuum switch tungsten copper material, it has high strength of porous W skeleton, low gas content, Cu has network-like distribution, tungsten copper matrix bonded tightly.