The invention belongs to the technical field of
mineral processing engineering, and particularly relates to a composite binder for
iron oxide ore
pellets and a pellet preparation and
arsenic removal method thereof.
Calcium carbonate-
ammonium bicarbonate serves as a composite binder, efficient
arsenic removal is achieved through the unique action mechanism of
ammonium bicarbonate,
iron oxide ore
powder and a composite binder solution are mixed and pelletized to obtain green
pellets, the green
pellets are cured for 5-8 h at the temperature of 20-30 DEG C and the
humidity of 60-80%, dried for 3-4 h at the temperature of 100 + / -5 DEG C and roasted for 2-4 h at the temperature of 600-800 DEG C;
ammonium bicarbonate is decomposed during
roasting to generate NHH, the NHH reacts with
arsenide in the pellets to generate volatile
arsenic ammonia compounds, arsenic removal is completed along with gas escape, and meanwhile
calcium carbonate provides framework support for the pellets to guarantee strength. The arsenic removal rate reaches 85% or above, the arsenic content of the pellets is reduced to 0.02% or below, the
compressive strength of dry pellets is larger than or equal to 2000 N / pellet, the
roasting temperature is reduced by 30% or above compared with a traditional technology, low-energy-consumption and high-purity clean utilization of
iron oxide ore resources is achieved, the technological process is short, and the method is suitable for industrial application.