Physicochemical Characteristics of Gold Sulfide Refractoriness
A close association of fine gold with pyrite and arsenopyrite is observed at many gold ore deposits.Gold forms and gold distribution in sulfides of different deposits were studied.A comprehensive method including optical spectrum analysis,X-ray diffraction analysis,high-temperature X-ray diffraction analysis,scanning electron microscopy and X-ray microanalysis was used for the detailed investigation of the defectiveness of the structure of pyrites from different deposits.It was shown that gold content in pyrites varied from 1.5 g/t to 100 g/t compared with 30 g/t to 230 g/t in arsenopyrites.The nature and arrangement of inner inclusions of foreign minerals in pyrites as well as occurrence of fractures and macro- and microdefects were examined.Iron,sulfur and arsenic contents in all pyrite samples were determined.Chemical composition of the detected inclusions was defined.Parameters of submicroscopic structure of pyrite were estimated using X-ray Fourier line shape analysis.Estimation of real structure characteristics with calculation of submicroscopic D-blocks and root-mean-square lattice deformation √(ε2) values was performed.Defectiveness of the pyrite structure can be defined by the following parameters: Ká1 and Ká2 reflection resolution and its intensity within high Bragg angles;S content to Fe content ratio;the arsenic content and the local variation in its concentration within the pyrite grain;the size of submicroscopic blocks and the crystal lattice disturbance value.The performed analysis showed some relationships between these parameters and refractoriness of the pyrite concentrates.It was observed that at S/Fe ratio close to or higher than stoichiometry and at a low arsenic content (less than one per cent) pyrite concentrates were not refractory.The analysis results showed that concentrates of the Beryozovskaya gold plant (0.02～0.07 As%) and concentrates of the Kommunarovskaya gold plant (less than 0.05 As%) as well as some pyrites from the Sukhoi Log gold deposit had the same characteristics.It was found that average arsenic content did not excess 0.2 per cent.Arsenic distribution within the grain of all these pyrites was uniform.At S/Fe ratio lower than or close to stoichiometry and at high arsenic content (more than one per cent) and significant variation in its distribution within a pyrite grain the pyrite concentrates are refractory.Such pyrites are typical for the Sukhoi Log,the Bakyrehik and the Mardzhanbulak gold deposits.Direct correlation between arsenic and gold contents,in particular,in free grains of pyrite was observed by many researches.This correlation was explained by impregnation of arsenopyrite which normally contains more gold than arsenic pyrites.The analyses results showed that no arsenopyrite impregnation was found: arsenic distribution within the grain was uniform but its concentration varied greatly.Such pyrite concentrates are more refractory.This paper presents the results of analyses of sulfides to determine the amenability of the associated gold recovery by hydro- and pyrometallurgy.
Refractory concentrates Sulfides Pyrite Arsenic Gold
S.V.Balikov
Irkutsk Research Institute of Precious and Rare Metals and Diamonds.IRGIREDMET JSC,Irkutsk,Russia
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
4341-4349
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）