Online Gold Analysis Using X-ray Fluorescence
Erfan Sharifi, Outotec (Canada) Ltd.; Juha Timperi, Outotec Finland Oy; Tommi Koskinen, Outotec Finland Oy; Antti Pelli, Outotec Finland Oy
Accurate real-time elemental analysis is one of the most important online measurements to enable efficient flotation circuit control and to achieve optimal metal recovery. In base metals concentrators, online elemental analyzers have been utilized for process control since 1960s resulting in high process performance. In gold concentrators, valuable metal content in most process streams is typically so low that direct measurement of gold is only feasible for concentrate streams with higher gold contents. Traditionally, gold content in flotation feed has been estimated according to direct measurement of elements such as iron, copper and arsenic. These indirect measurement models have proven useful in some applications while providing reliable estimate for real-time gold content. However, there are several applications where indirect measurement models are not feasible due to changes in ore properties or due to presence of free gold that cannot be estimated according to other elements. This paper presents result of direct gold measurement using an online XRF elemental analyzer that has been optimized for measurement of precious metals.