Mining and marketing company Glencore produced 40% more cobalt last year, along with 16% more oil, 5% more nickel and 1% more ferrochrome.   Although coal production of 110-million tonnes was 6.7-million tonnes higher, on a like-for-like basis, overall group coal production fell by 7%, primarily owing to wet weather challenges and an extended community blockade in Colombia, where Glencore now owns 100% of Cerrejón.   ...