Hello rohitdigit:

I assume you are absorbing the molten sulphur with the silicone carbide blocks or disks?

As the MP of silicone carbide is 2730 °C, and the MP of Sulphur is 115 °C, will putting the silicone carbide into the sulphur, and just letting it 'cook' for a while allow the sulphur to be absorbed?

Yes .. the MP of sulfur is important... to maintain certain viscosity to penetrate the pores of Sic block, the MP of Sic has nothing to do with it, the aim is complete - 100% of pores are filled thorowly with sulfur that solidifies on cooling...

Hello rohitdigit:

I know this may sound ridiculous but, it may not fully absorb the sulphur because of 'residual' pressure. Have you tried dipping the silicone carbide in the molten sulphur and leaving just a tiny bit above the molten liquid. This may allow any residual pressure to dissipate through the end?.........Just a thought, OK?

Thanks Babybear for the concern, Yes we have done lot of experiment even leaving the stone partially above the molten sulfur, but the cappilary action in the pores even do not work. The penetration in the exposed part is much much less. Any idea of some surfactant that acts as absorbant for Sulfur????.....

Is it feasible to diffuse the S in as a vapour and condense insitu?

Not sur... can be tried ..... some idea??????

Keith (#5) gave a similar reply to what I would have said, only he said it far better.

Hello sceptic:

Keith (#5) gave a similar reply to what I would have said, only he said it far better.

You know I have the same problem all the time! My nick name is "if only"!

Take care

Hello Keith E Bowers:

I like the way you think and, like your post.

I wonder how other grinding wheel manufacturers have gotten round this problem? It seems to me that very slight adjustments in varying 'salts', as well as slight heat changes effect how much of the Lube, in whatever form, is absorbed?

I like your idea but wonder how it would be into practice comercially?

Take care and a good answer!

Thanks babybear… I do think we are zeroing in to the problem with multi-ideas…

Yes we do make our own blocks, but they are moulded to a single size, thinner one are better but not the best in absorbing sulfur, the problem is with micro-pores of thicker blocks.

I searched for surfactant…. But could find nothing pin pointing to improve the surface of Silicon carbide…. Or help improving absorption.

Your abstract are useful….. but for the Silicon Carbide grain Manufacturer point of view, we use the pre manufactured Sic grain for converting them to block. They are fine abrasive powders and hard additive or non abrasive additive could reduce their cutting strength or even contaminate interfering with their cutting efficiency….. Still Thanks again for the abstract too, knowledge what so ever is always usefull ….

Please excuse my ignorance. What does the sulfur do that is advantageous to the performance of what I assume is an abrasive wheel?

I would have thought that the impregnation of the sulfur would be incline to throw the wheel of balance unless you can achieve homogeneity.

An out of balance wheel can waste a lot of setup time and produce a poor surface finish.

BAB

Hello BlueAussieBoy

The ideal is to achieve 'homogeneity' and thus balance. Which may be the reason for the start of this thread?

Sulphur is used as a Lubricant, mixed with a liquid it is absorbed by the wheel or other grinding surface.

I have copied a short piece to explain the reasons from this site:

http://findarticles.com/p/articles/mi_qa3618/is_200802/ai_n24394308/pg_3

[The term sulphurchlorinated fluid refers to fluids that contain both sulphur and chlorine. These are generally all-purpose fluids. Chlorine reduces the coefficient of friction at low interfacial temperatures, and sulphur reduces the coefficient of friction at high interfacial temperatures. Due to the very high temperatures in the arc of cut, it's a sulphurized fluid that will have the most impact on the grinding process].

Hope it makes things clearer\! I too wondered and thought there may have been a Lubricating type of reason and know I also know!

Thanks Babybear, that makes things a lot clearer.

I use to use sulphurchlorinated oils back in the days when I was making tools. It worked very well but it had a distinctive smell to it that went right through the workshop and your overalls.

It is an interesting concept to pre-load the wheel with the lubricant/coolant. On small diameter wheels it may be OK but large wheels, say a foot or over it may be a challenge to get the full penetration to ensure balance.

BAB

Hello BlueAussieBoy:

I am not sure what has always been done since someone invented the absorption method for this lub'. There is other wheels which do not have this in the make-up. But, as the originator of this thread says, he is having trouble getting the Sulphur to soak through 100%.

BlueAussieBoy

Thanks for the reference. Very helpful and interesting

Hello rohitdigit:

Thanks for the answers to my questions. I was thinking it may be possible to mix powdered sulphur with the grains before they are formed? Or would this burn the sulphur away as it heats up?

Hellow Babybear

Mixing Sulfur into the initial stages to form, cannot work as on heating above 120 D Cen it will leave the matrix?? It has to be done after sintering only. I feel Nitrogen has great affinity to Sulfur and can form long chain, hence the stone can be pretreated with some Nitrogen in gaseous stage or with compound & then reacted with sulfur for better result ..... any suggestions..... Looking for Chemical Engineers to step in to say about the reaction. Since Sulfur/Nitrogen can be explosive too.