Binder for pelletizing?

Question

I want to pelletize lignite(a kind of coal) for using in agriculture. But it is soft and pelletizaing is very hard. What can I do? I want a cheap and harmless binder or other thing that can help me

Answer 1

A method is claimed for pelletizing carbonaceous materials including bonding coal fines and lignite coal with a polymeric hydrocarbon binder having reactive sites thereon.^For example, with tall oil pitch and the like, in the case of coal, the binder is applied by slurrying the fine coal with the pitch.^In the case of lignite, the binder is directly applied to the pulverized material.^By action of rolling and tumbling, for example, large agglomerates are formed.^With drying and heating, strong water-resistant pellets are formed which have the extremely desirable property of being easily repulverized.

http://www.osti.gov/energycitations/prod...

Answer 2

if you want an inert binder you might try bentonite, a clay.  If you want an organic binder you might try wheat millrun.  Both will make a very hard pellet.  There are other clays that are used for binders too.