The very first process in the Cold Rolling Mill Complex (CRMC) involves cleaning of the hot rolled strips in a pickling tank containing hydrochloric acid. The Acid Regeneration Plant (ARP) in CRMC, processes the used-up (waste) pickle liquor from the pickling tanks to "generate" fresh hydrochloric acid of around 18% concentration. The acid re-circulation works in a closed loop with more than 98% acid getting recovered from the waste pickle liquor.

However, the iron oxide that comes out as a by-product (600 tonnes per month at the peak rate of production), poses environmental problems of disposal/reuse / recycling. To resolve this, initially it was planned to send the entire amount of iron oxide to the sinter plants for making sinter. This practice was followed until recently for which, CRMC got a credit of about Rs. One hundred per tonne. But, the ARP team looked for better avenues of utilising this oxide in order to achieve higher returns for Tata Steel. An attempt was made to use this oxide in the paint industry to make pigments. But the product was not acceptable -the size was unsuitable and the impurity levels were too high.

Consistent efforts were made to modify the working parameters so as to make the product suitable for paint- making. The quality was improved substantially in terms of volatile matter, acidity, total iron content, colour, solubility and residue analysis. This satisfied the customer next-door -Tata Pigments. CRMC is now able to sell a substantial amount of this product at Rs. 3500 per tonne. Adding colour to this achievement, a new product called "Rangeela" using this iron oxide has been launched by CRMC. Some trial orders have already been received from other paint makers.