At a time of scarcity in everything from crude oil to copper to corn, nickel is heading for the biggest glut in four years, driving prices lower into 2012, Bloomberg reported. Next year’s surplus will rise to 60,000 metric tons from 12,000 tons in 2011, making nickel the most oversupplied metal relative to output or use, according to Bank of America Merrill Lynch. New mines will boost supply 11 percent in 2012, the most in 17 years, Bloomberg said. Prices may drop 12 percent to $20,000 a ton by Dec. 31, according to the median estimate in a Bloomberg survey of 17 analysts and traders. Prices reached a record $51,800 in 2007 and moved at least 63 percent a year since then, Bloomberg said.