Also, 1,8 million tonnes of miners' coal have to be eliminated, the distribution of that coal being exclusively in the hands of British Coal and related companies.
In this study, the effect of oxidation and the yield of humic acids extracted from a sample of Colombian mineral coal were studied by response surface methodology (RSM).
¡ Cuidado!- ¿ Te has vuelto loca?scielo-abstract scielo-abstract