Abstract: The invention provides a method for reducing impurities from roasted molybdenum concentrate (RMC), comprising: performing a first treatment in a first reactor, on a portion of the RMC forming a first treated suspension, the first treatment comprises adding the portion of the RMC to a water-solution, wherein the first treated suspension has a temperature from 10° C. to 100° C. and a first pH value of from 2.1 to 5.0; performing a second treatment in a second reactor on a portion of the first treated suspension, the second treatment comprises adding the portion of the first treated suspension to an acid solution to form the second treated suspension, wherein the portion of the first treated suspension has a temperature <70° C., and wherein the second treated suspension has a second pH value between 1.5 and the first pH value; and separating a portion of the second treated suspension from the reactors.

Abstract: A roasting furnace for processing ores or concentrates, preferably molybdenum-containing ores or concentrates is described. The roasting furnace contains at least one first rotary lifting system for the displacement of said arm along the axis direction, wherein said first rotary lifting system is a telescopic lifting system, and/or wherein a distance x between two consecutive said stages of said roasting furnace are at least 1.000 m, wherein said distance x is measured along the axis direction. The roasting furnace of has an improved processing capacity and/or a reduction in the number of halts, and consequently is more energy-efficient, more environmentally-friendly and more economically interesting.

Abstract: A roasting furnace for processing ores or concentrates, preferably molybdenum-containing ores or concentrates is described. The roasting furnace contains at least one first rotary lifting system for the displacement of said arm along the axis direction, wherein said first rotary lifting system is a telescopic lifting system, and/or wherein a distance x between two consecutive said stages of said roasting furnace are at least 1.000 m, wherein said distance x is measured along the axis direction. The roasting furnace of has an improved processing capacity and/or a reduction in the number of halts, and consequently is more energy-efficient, more environmentally-friendly and more economically interesting.