Roller type briquette machine v.s. Screw type briquette machine and Pelletizer for different types of coal.
Roller type briquette machines are originated from Japan but now mainly produced in China. The briquette making from coal is more difficult than charcoal. We have many coal plant customers (importing, crushing, sorting and selling) who are using roller type briquette machine from China and have problems with machine operation and binder handling (mixing, high percentage of binder required, water is also needed to add during binder mixing, drying).
These are points you need to be aware when talking to briquette machine suppliers.
Regarding screw type machine (what we are specialized), this type of machine is also not much suitable for bituminous/sub-bituminous coal type. But it works well for Coke coal and Anthracite coal but binder is still required (about 4-5% by weight).
The most we sold is the pelletizer which work very well with bituminous/sub-bituminous without binder (but if with coke/anthracite, binder is still required up to 2-3%). We installed many units for our customers already. However, the biggest proven machine that we have is only about 400-500 kg/hr, depending on size of pellet (typical 8-10 mm. diameter).