Strange magnetism of graphite

I'm not suprised that a pencil attracts a magnet. Pure graphite can be made by heating carbon powder, but it comes from mines. I recall that pencil graphite is also hardened by mixing it with clay ...and the magnetic properties of carbon depend on impurities as well as upon the crystal structure. If graphite from a mine has enough paramagnetic contaminants (such as ferrite, like lodestone,) it will attract more than it repels.
On the other hand, are you sure that the pencil carbon is acting weird? Some paint pigments are paramagnetic and will weakly attract a magnet. To assure that it's carbon contamination which causes the attraction, use some wire cutters to snip the wood off the graphite rod, then experiment with just the graphite. Perhaps see if the remaining wood and paint will also attract or repel from a strong magnet.
As a science project you could also try using a blow torch and a fire brick to burn off the graphite to see how much other stuff is left behind. Pure carbon burns into CO2, but pencil leads should leave behind some ash which is possibly magnetic.
Now if you want some REALLY diamagnetic carbon, buy some pyrolytic graphite from a science hobby supplier. The repulsion effect is so strong that a small flake of graphite will hover in space above a strong magnet pole.

XRD Graphite Listed in Guangdong Financial Equity Trading Centre

In June 19,2015 which is a memorable day for XRD Graphite. XRD Graphite Manufacturing Co.,Ltd. officially listed in Guangdong Financial Equity Trading Centre.

Audit Committee reviewed equity dispute and Property disputes of Pingdingshan XRD Graphite Manufacturing Co., Ltd.Finally XRD graphite passed all the appraisal in various conditions and conform to list enterprise standard.

XRD Graphite listed in the center of the guangdong financial equity trading which is a significant milestone for our company. On the one hand,it make company funds diversified and greatly broaden the financing channels, on the other hand,it also plays a big role in enrich the company's funds and improve the company's management level to speed up the growth of the company.XRD Graphite achieved to go out and attract to company in the equity trading market. 

XRD Graphite improved the company reputation, influence, the important stage of enterprise brand by this listing in Guangdong Financial Equity Trading Centre.

Article From: http://www.xrdcarbon.com/news/127.html

Graphite Stopper

Considerations Of Graphite Crucible When Used

Graphite crucible has good thermal conductivity and high temperature resistance,when used at high temperature,it has certain strain resistance to thermal shock and quench.it also has excellent chemical stability,so it has strong corrosion resistance to acid and alkaline solution.it’s widely used in many industries.so it’s necessary to list the considerations of graphite crucible when used.

1、When Handled it should be light up light put,do not break the surface coating,avoid rolling by all means.

2、Stored in a dry environment,must not be affected with damp.

3、When Used for coke oven,it should be used crucible holder,crucible holder diameter should be slightly bigger than the bottom graphite crucible diameter,fully support the bottom of graphite crucible.

4、Shall not be tilted when inside furnace,top of the graphite curcible is not higher the furnace.between the furnace and the crucible,should be used wall brick,the wall brick is higher the crucible.the cover of the furnace should be on the furnace wall.

5、the coke briquette should be smaller than the spacing of furnace wall and the crucible,which is automatic fall,shall not be ramming.

6、The heat temperature of Graphite crucible need to up to 200℃ for 1-1.5 hours when used at the first time.then one hour up to 800℃,the baking time should not be too long.(first baked,graphite crucible should be rolled constantly,The temperature of the crucible should be slowly up inside and outside,up and down of the crucible,and shall not exceed 100 ℃,when it Stays cool,continues to heat up after water vapor discharges)

7、Furnace lining must keep in good condition,so it can focus the flame.

8、Adopt heating burner,flame should not be direct injection on the crucible,but the crucible holder.

9、Use The same crucible tongs when raised and  loaded.

10、When raised,broken material first then the metal ingot.But not too close and placed horizontally.avoid crucible cracked due to the metal expansion.

11、Better to continuous melting when graphite crucible startd to use,reduce the interval of time.

12、If Stoped in the middle time,The residual liquid should be all clear,avoid crucible cracked when used the next time.

13、In the process of smelting,The dosage of refining agent must be strictly controlled,if too much,it will reduce the life of graphite crucible accordingly.besides,Junction of ballastless must be cleared,which affects graphite crucible and triggers the broken of the upper crucible at the same time.

Article From: http://www.xrdcarbon.com/industry_news/125.html

Graphite Powder-The Application In New Energy Battery

Now the number of cars are increasing,gasoline price is more higher as followed.so people are starting to develop new energy vehicles instead of burning gasoline cars.a new energy battery can provide power for new energy vehicle,and in the new energy battery,graphite powder in the innovation of new energy car battery,which can speed up the new energy battery cars into the market fast.

Graphite powder is an important material in the new energy battery,but now the new energy vehicles have not reached practical purpose,they can only run within a short distance.Now researchers are researching new energy battery,which can make new energy cars more practical.In the new energy battery,the graphite powder is an important part because graphite powder has good electrical conductivity.graphite powder in the battery can be made into graphite conductive films,graphite anode materials and graphite conductive liquid,etc.Because the graphite powder has good electrical conductivity,the graphite powder has advantages of fast charging and discharging speed,big storage capacity etc in the battery.Now we has successfully trial-produced new energy car battery,which can be full of electricity in 15 minutes,the travel time and distance also has greatly improved.

The application and research of Graphite powder in new energy battery will continues,because there are many areas needed to improve.Graphite powder needs required further research and development,then the performance of battery that graphite powder further reforms. 

Article From: http://www.xrdcarbon.com/industry_news/122.html

The Applications Of Graphite Mould

Currently,graphite mould has been widely used in the following aspects:

1.Non-ferrous metal continuous casting graphite mould and semi-continuous casting graphite mould

In recent years,synthetic graphite is considered to be the most suitable material for continuous casting of nonferrous metals or semicontinuous casting mould.Production practice has proved that the adoption of graphite mould,which not only improve the casting speed, but also due to the size of the ingot casting precision,smooth surface,uniform crystal structure,it can be directly for the next working procedure of processing,all due to its good performance of thermal conductivity.This not only greatly improves the yield,reduce scrap loss,but also has greatly improve product quality.

Continuous casting method has vertical continuous casting method and horizontal continuous casting method.

2. The compression casting graphite mould

synthetic graphite material has been successfully used in non-ferrous metal pressure casting.for example,zinc alloy and copper alloy castings made by compression casting mold have been used to automobile parts,etc.

3. The centrifugal casting with graphite mould

Graphite mold has been successfully applied to the centrifugal casting.In order to prevent synthetic graphite mould of burning,we can take certain measures of anti-oxidation.After casting a certain numbers of castings,if found mold surface burned, we can expanded mold inner hole size so that used for casting large size casing.

4. Hot pressing graphite mould

synthetic graphite hot pressing mould used for cemented carbide pressure sintering has the following features:

If the suppress temperature is up to 1350-1450 degrees,the unit pressure can be dropped to 67-67 KGF/cm2 ,that's 1/10 of cold pressing pressure ;Secondly,the pressure and heat is in the same process.

5. Glass molding with graphite mould

Due to graphite material with chemical stability,it will not change the composition of the glass,graphite material thermal shock performance is good,and small size changes with the temperature characteristics,so in recent years it becomes indispensable materials in the glass manufacturing mould,it can be used to manufacture glass tube,pipe,funnel and other forms of special shape of glass bottle mould.

6. Sintering mould and other

little thermal deformation of synthetic graphite material,it can be made the transistor sintering mold and support,so it is now widely used,it has become the indispensable material in semiconductor industry.And graphite mould is also used in cast iron, the durability of various non-ferrous metalsmould, casting steel mould,refractory metals (titanium, zirconium, molybdenum, etc.) with mold and rail aluminothermic welding with welding type of mould, etc.

XRD Graphite Manufacturing Co.,Ltd----China Graphite Supplier And Graphite Machining,Graphite Manufacturer,Official Website:xrdcarbon.com

Article From: http://www.xrdcarbon.com/industry_news/116.html

How to Deal with Graphite Dust 2

In part one of this article, we touched briefly upon possible health effects of graphite dust and that the type of synthetic graphite used for electrodes does not particularly pose serious health implications as long as adequate dust collection is used. We also examined two types of dust collection systems and the proper air flow to achieve maximum dust evacuation. In this article, we will look at the flammability or explosive potential of graphite dust.

Controlling Dust 
When we think of controlling dust in the workplace we often consider how to reduce or eliminate the potential of inhaling dust particles to prevent health issues. Unfortunately, the consequences of a fire or explosion caused by accumulated dust in the workplace can be far greater.
Dust is an ever present condition in a manufacturing environment and generated by a myriad of processes that include production equipment, material handling and machining. The creation of this dust does not inevitably lead to safety and health risks if accumulation levels are kept within limits through effective housekeeping and dust collection practices. However, when excess amounts of dust are allowed to accumulate and then introduced to an ignition source, the results can be catastrophic.

Explosive Potential of Graphite Dust
Dust explosions in manufacturing plants over the past decade have certainly gained media attention as these tragic events resulted in needless loss of life and property. The devastation of these events also caught the attention of the Occupational Safety and Health Administration (OSHA).
In 2008, OSHA Directive CPL 03-00-008 was issued and states, “This directive contains policies and procedures for inspecting workplaces that create or handle combustible dusts. In some circumstances, these dusts may cause a deflagration, other fires, or an explosion.”¹ As a result of this directive, facilities that generate dust through a number of processes, including machining graphite, should conduct an assessment of their practices to determine the potential of a dust explosion and develop practices to lessen the probability of this occurring. The primary objective of this assessment is to identify if dust particles are combustible and in concentrations sufficient to ignite.

Combustible dust is identified as, "Any finely divided solid material that is 420 microns or smaller in diameter (material passing a U.S. No. 40 Standard Sieve) and presents a fire or explosion hazard when dispersed and ignited in air."² The elements of fire include fuel, oxygen and ignition. A dust fire or deflagration occurs when sufficient concentrations of fine particulates are suspended in air and then exposed to a source of ignition such as a spark or welding igniter. This ultimately results in the igniting or combustion of the dust.

In regard to a dust explosion, two additional elements are added. These are dispersion and confinement. If the dust is dispersed in sufficient volume or a dust fire is in a confined area, then the potential of this developing into an explosion is significantly increased. Controlling any one of these elements will essentially eliminate the potential of a dust explosion. To overcome the potential of a graphite dust explosion, the industry has primarily relied on controlling the element of fuel by removing dust at the source through effective vacuum systems. However, this does not minimize the need to address each element and determine practices to mitigate its contribution to an explosion.

In order to increase its effectiveness in controlling the dust and reducing the potential for a fire or explosion, all dust control equipment involved in handling graphite dust should have explosion relief vents, an explosion suppression system or an oxygen-deficient environment. Having adequate general ventilation is the first step and should be sufficient to also limit the employee exposure to airborne contaminants such as graphite dust particles.³

Explosibility Testing It is beyond the scope of this article to identify the full testing process in determining the explosive nature of graphite however; explosibility tests of graphite dust generated from the machining operations at a qualified laboratory were conducted.4 The results of this testing (see Table 1) will provide the customer with an indication of the explosibility for the graphite dust tested. However, due to variability in conditions, each customer will need to perform the explosibility testing for their conditions to have correct data to make a valid assessment of their activities.

The results of the laboratory tests indicate the graphite dust used in these tests are “hard- to-ignite” even with low moisture content and high concentration levels where 98.5% of the particles are less than 500 micron in size.

To reiterate, combustible dust is defined as a solid particle being 420 micron or smaller that can be ignited. In a shop environment, at the concentration levels of these tests the graphite dust would most likely be thick enough to hinder visibility. Therefore, the bottom line is that the potential of experiencing a graphite fire or explosion is minimal as long as good ventilation and sufficient dust collection is present, and effective cleaning and maintenance programs are utilized.

In some cases, additional information can be provided by the manufacturer. One possible source for information on combustibility is the Material Safety Data Sheet (MSDS) for the material. Hazard statements should be contained in each MSDS that identify if the material is a combustible product in its present form or a future transformed form. The MSDS will should also identify the exposure controls limits as well as the Hazardous Material Information System (HIMS) and National Fire Protection Agency (NFPA) rating. Contact your graphite supplier for a copy of the MSDS for your specific material.

SummaryAlthough the aforementioned tests conducted have shown graphite dust to be “hard-to-ignite,” this does not release companies from the responsibility of continual improvements in dealing with graphite dust. Recent times have seen the development of practices meant to improve the ability to identify an explosion risk. These practices often include safety monitoring equipment, improved dust collection systems and the implementation of an effective safety program that offers good housekeeping practices and an efficient preventive maintenance program.
While a dust fire or explosion cannot be completely eliminated, the use of these practices significantly reduces the possibility of this occurring. Being aware of the elements for a dust fire or explosion, knowing the explosive potential of the graphite dust and what resources are available for further information greatly improves the ability to identify potential risks and eliminate them before it is too late.