Hindustan Copper Limited has to its credit some major contributions towards technological improvements in mining, beneficiation, smelting, hydrometallurgy and by-product recovery. Some of the areas where Hindustan Copper Limited has introduced new technology are
Trackless mining has helped in rapid development of mines enabling higher levels of production and productivity comparable to international standards.
Raising is one of the most difficult of mining operation, HCL has developed and perfected the concept of drop raising over 60m intervals. This has resulted in increased-safety and higher progress. A pattern of five 6” diameter holes has been standardized for the crater method of blasting the raises sequentially.
HCL has developed single sub-level method of stoping using large diameter (162 mm) blast holes over level intervals of 50 to 60 meters. Need to have intermediate sub-level for drilling has been eliminated in this method. Excellent fragmentation has been achieved. Benefits of new stoping method compared with the conventional sub-level stoping methods are:
Reduction in quantum of developments, drilling cost and explosive cos
Overall reduction in the cost of mining
Reduction of manpower and
Reduction in stopes preparation time. The new method of stopping has revolutionized mining technology.
For mining flat dipping ore bodies, timber support was common in early days. With the need to mine over a large width. HCL developed very simple but effective methods of rock bolting using cement grouted steel rods. This has resulted in the improvement of ground conditions ensuring higher safety standards.
HCL has developed the post-pillar method of mining for adoption in flatly dipping wide ore bodies in ICC group of mines. This mining method has enabled the production rates to go up as compared to room and pillar stopes. Electrically operated LHD 's have been introduced at ICC for operating in these stopes. The output per man shift has increased and the stoping cost has come down substantially. Hydraulic filling of stopes with classified mill tailings has been established as a standard practice at the ICC resulting in regional improvement in ground conditions.
HCL has also taken the lead in introducing oxygen enrichment in the converters at KCC and ICC resulting in effective control of accumulation of secondary products in smelting. HCL has also introduced oxygen enrichment in process air in flash furnace to effectively increase the capacity of the existing smelters for meeting increased production commitments.
Occurrences of large quantities of oxidized ore and lean grade sulphide ore at Malajkhand has impelled the company to extract copper values in the ore by dump leaching otherwise uneconomical by conventional methods. The dump is sprayed with dilute acidified solutions to dissolve copper minerals. The end products of this leaching operation is a pregnant liquor of copper sulphate. The leached liquor is then treated to recover copper metal.
HCL has established well equipped R&D facility at KCC and ICC. The R&D section is fully responsible for improvement in quality of the products, control of quality of raw materials, improvement of recoveries and for maximizing the recovery of by-products, HCL has developed its own Precious Metal Recovery plant which is now operating at ICC successfully. A Tellurium Recovery Plant has also been developed by R&D Wing. Extensively trails are going on for recovering cobalt, nickel and copper powder from converter slag. Attempts are also being made for reducing the losses from slag.