Optimized Combined Processing Technology for the Accumulated Refractory Copper Ore Tailings at Madneuli Deposit

"Processing of the tailings accumulated over the lifetime of Madneuli Copper Concentrator is an opportunity to extract additional salable copper and gold products. This paper presents a pre-concentration process for the valuable components (copper and gold) of the accumulated tailings. The developed process makes it possible to obtain a copper pyrite concentrate with a yield of 14.05%, copper grade of 1.36%, and recovery of 83.22% containing 3.78 g/ton of gold at a recovery of 84.31%. The bulk concentrate is produced by a combined process bringing together selective flotation to produce salable copper concentrate and hydrometallurgical processing of the selective flotation tailings to recover gold. KEYWORDS: FLOTATION, ALBION PROCESS, LEACHING, COPPER CONCENTRATE, SELECTION Madneuli Copper Concentrator, Georgia, was put into operation in 1975. Over its lifetime, 40 mn tons of tailings have been accumulated at the tailings storage facility (TSF). Sampling of the TSF has indicated that the average copper and gold grade is 0.23% and 0.56-0.65 g/ton, respectively. Accordingly, the TSF can be classified as a technogenic reserve. This paper discusses pre-concentration of valuable components using flotation, followed by processing of the bulk concentrate in the Albion process. Mineralogical analysis of the accumulated tailings showed that the main ore mineral is pyrite (11.71%). Copper minerals are mainly represented by chalcopyrite (0.7%). The main nonmetallic mineral is quartz (67.3%); sericite, chlorites, etc. also occur. Pyrite is present both as liberated grains and intergrowth. The absolute majority of copper minerals are found as intergrowth with pyrite, less often with quartz. Ore minerals are slightly oxidized. Chemical analysis results are shown in Table 1. Particle size distribution shows that the size class -0.2 mm - 0.045 mm has the highest grade of 0.85 to 0.97 g/ton of gold. Size class +1.25 mm has the lowest grade. Based on the chemical and mineralogical studies and particle size distribution, an optimized process was developed for pre-concentration of the valuable components prior to hydrometallurgical processing. Several gravitation, direct selective, bulk, and bulk selective flotation processes were trialed. (1,2)"