rCB (recovered carbon black)

rCB stands for recovered carbon black. It is the upgraded, saleable form of the carbon char that remains after end-of-life tyres or plastics are processed by pyrolysis — heated in the absence of oxygen so the material breaks down into oil, gas and solid carbon. The raw char is a dusty, contaminated residue; once steel and fibre are removed and the material is milled and pelletised, it becomes rCB, a manufactured carbon product with a market price.

rCB competes against virgin carbon black, the reinforcing filler used in tyres, hoses, belts and many rubber and plastic goods, which sells in India broadly at Rs 80-130 per kg by grade. rCB typically sells at 40-70% of the virgin price, but because the char is produced as part of the pyrolysis process its incremental cost is low, so the margin per tonne can be high. In tyre and plastic pyrolysis economics, rCB is usually where the profit sits — the pyrolysis oil tends to cover running costs while the rCB carries the return.

Quality decides the price. The main parameters are ash content (ideally below 10-12%), residual hydrocarbons, particle size and surface area. Low-ash, finely milled rCB can replace N660-grade virgin black in semi-reinforcing rubber compounds; high-ash unprocessed char is restricted to low-grade fillers, pigments or sale as carbon fuel at a fraction of the value. Many Indian units forfeit most of this value by selling unmilled char, because they have not added the finishing line.

For an Indian operator the practical steps mirror the product itself: install magnetic and screen separation, a micronising mill and a pelletiser; get the output tested at a NABL lab for ash, sulphur and surface area; and sell against a documented specification — ideally under an offtake with a rubber compounder rather than into the loose spot fuel market. See the fuller entry on recovered carbon black for processing detail.