Japan’s Sumitomo Metal Mining Co. Ltd. (SMM) on Monday announced that it has developed a new technology that would allow the company to make use of low-grade iron from nickel ore, which is usually subject to disposal in landfills.
In a statement posted in its website, SMM said that it has succeeded in raising the grade of the iron from its tailings to about 60 percent, which is equivalent to normal iron ore, using its high pressure acid leach (HPAL) processing technology in the Philippines.
Previously, SMM produced nickel-cobalt mixed sulfides using HPAL technology and the tailings left contains iron in the form of hematite. The grade of the hematite, however, is low at approximately 30 percent to 40 percent.
Nickel-cobalt mixed sulfides are intermediate products for the production of materials including electrolytic nickel. SMM processes all of these mixed sulfides at its nickel refinery in Niihama City, Ehime Prefecture, Japan where these are processed into electrolytic nickel and electrolytic cobalt products.
Hematite is mainly used as raw material for iron and steel.
“As such [low grade]cannot be used as a raw material for iron and steel, meaning it is subject to disposal in landfills,” the company said.
“Through a review of the process after the leaching and recovery of nickel and cobalt using HPAL technology, SMM has succeeded in developing a technology that would raise grade of the iron in the tailings,” it added.
SMM said that when this technology is developed for commercial use, not only will it allow a more efficient utilization of resources but it will also make a large contribution to reducing the amount of waste disposed in landfills.
Through its 62.5-percent owned subsidiary Taganito HPAL Nickel Corp., SMM plans to commence production of nickel-cobalt mixed sulfides using HPAL in the fourth quarter of 2013 and is also planning the construction of a pilot plant that uses the new technology.
“SMM shall henceforth move forward with investigations into making this technology viable for commercial use,” the company said.
SMM was the first company in the world to succeed in using HPAL technology to commercially produce nickel and cobalt from low-grade nickel ore, and is also making efforts in the recovery of valuable metals from ores and residues in order to achieve an even more efficient usage of resources.
Coral Bay Nickel Corp. (CBNC), which is located in Palawan, is producing nickel-cobalt mixed sulfides using HPAL technology, and construction of a pilot plant for the recovery of scandium and chromium is also underway.
“Along with these efforts, it is hoped that making use of iron from nickel ore will promote the efficient utilization of resources in line with the 2012 Three-Year Business Plan key strategy expansion of metal recovery,” SMM said.
In March 2013, the company announced plans to construct a scandium oxide pilot plant at CBNC by the end of this year and for trial production to get under way at a level of 10 kilograms a month in 2014.
Rare earth metal
Scandium, a silvery-white metal with a density of 2.99, is a rare earth element discovered in 1879.
It is used in a variety of applications, such as an additive to enhance the strength, heat resistance and corrosion resistance of aluminum; as an electrolyte used in solid oxide fuel cells and as an electrode used in metal halide lamps and alkaline batteries.
SMM said that small quantities of scandium are contained in the ore used at CBNC in the production of nickel-cobalt mixed sulfide applying SMM’s high-pressure acid leach technology.
For some time, SMM has been working to develop a scandium recovery method at its Niihama Research Laboratories in Ehime Prefecture. Currently, global production of scandium is estimated at 10 tons a year.