Experimental Study of Supergene Processes in Tailings of Copper-nickel Ores
The results study the minerals oxidation were obtained by us during the methods of microscopic,FT-IR spectroscopic,XRD and chemical analyses of sulphides in tailings of copper-nickel wastes in Kola peninsula.Sulphide minerals begin to oxidize already at the stage of stockpiling and initial stages of storing.The proportion of non-ferrous metals and magnesium oxide increases with time,calcium partially precipitating in the form of gypsum.Comparison of heavy metal contents in pore solutions in current and stale copper-nickel ore concentration tailings has revealed a significant difference in practically all the parameters.The lower metal contents in current tailing pore solutions (by 5～30 times)are probably due to the presence of float reagent residues blocking oxidation.Much lower concentrations of magnesium and calcium can be accounted for by the difference in kinetics: the rate of sulphide oxidation at this stage is much higher than that of solution interaction with non-metallic minerals as the result of which the solid phase solution equilib.rium is not achieved.It is generally believed worldwide that it the mining wastes with acidic pore solutions that pose the greatest hazard for the environment.Our findings suggest that although the solution pH in all the samples is higher than 7.8,the contain heavy metal concentrations by far exceeding permissible values.The direct determination of the total and silicate Ni contents in the tailings from current production and in storage tailings has shown that both sulphide and silicate Ni forms occur in tailings.However,the role of silicate Ni is much larger in the storage tailings.The average silicate Ni content accounts for 10% of the bulk Ni content in the current tailings and it increases to 40% in the storage tailings.Thus,the storage tailings are marked not only by sulphide oxidation and the removal of water-soluble sulfates,but also by the interaction of sulfates with the silicate matrix.Although complete equilibrium is not achieved even within 30 yr under polar-region conditions,the major part of the Ni in fine-grained fractions passes into silicate form.The probability of Ni transition to the silicate form directly correlates with the dispersion of the material and the amount of chemically reactive serpentine and hydrochlorite.The migration of Ni as sulfates and its precipitation by chemically active silicates distorts the distribution of this component in the coarse- and fine-grained fractions that are typical of tailings from the current production of copper-nickel ores.On the one hand,the variation of the mode of Ni occurrence in storage tailings lowers the value of technogenic raw materials as a source of this metal.
Supergene Process Tailings Copper-nickel ore
V.A.Chanturiya D.V.Makarov T.N.Vasileva
Research Institute of Comprehensive Exploitation of Mineral Resources,Russian Academy of Sciences,Mo Institute of Chemistry & Technology of Rare Elements and Mineral Raw Materials,Russian Academy of Sc
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
3453-3460
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）