عنوان مقاله [English]
The Khanik-Qazan placer deposit is located at 82 km northwest of Urmia city, western Azarbaijan province. This area is a extremity northwest part of the Sanandaj-Sirjan structural zone. Microscopic studies show that ilmenite, ilmeno-magnetite and magnetite are the main ore minerals and layered gabbros are the main source rocks of these ore minerals. The prospecting activities in this area indicated good results relating to the existence of economic potential of ilmenite and titano-magnetite placer resource. Investigation of particles size distribution of representative total sample of the placer, indicated that 68 vol% of placer sample has sand size (< 2.36 mm), and the residual portion has gravel size (> 2.36 mm). An exploration plan was designed according to field geology studies, preliminary chemical analyses and prepared topographical and geological maps (1/5000 and 1/2000 scales). Eight trenches (a total length of 778.5 m and 1747 m3 total volume with 131 representative samples) and 43 test pits (a total depth of 140.3 m and 362 m3 volume with 121 representative samples) were drilled during the exploration phase. Geochemical analyses (carried out by XRF method) show that the grades of TiO2, ranges from 0.6 to 3.29 wt% (1.72 wt% in average) in exploration trenches and 1.01 to 4.83 wt% (2.39 wt% in average) in test pits. Vertical cross sectional method and geostatistical methods were used to reserve estimation of the placer ore. The estimated ore (in proved category) were measured 12 Mt with TiO2 grade of 2.338 wt% by classic method. Based on liberation degree study, suitable particle size for grinding of sand and gravel fractions were determined -500 µm and -250 µm for sand and gravel fractions, respectively. Mineral processing (ore dressing) studies show that the fraction +70 mesh (+210 micrometer) of sandy part of the Khanik-Qazan palcer ore have high concentrability, so that, an ilmenite concentrate containing 40.11 wt% TiO2 and recovery percentage of 86.41 are produced by using spiral classifier as primary concentrator and shaking table as final concentrator.