Engels, J, McPhail, GI, Jamett, R & Pavissich, C 2012, 'Evaluation of the behaviour of high density tailings deposition – CODELCO pilot plant', in R Jewell, AB Fourie & A Paterson (eds), Paste 2012: Proceedings of the 15th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 197-212, https://doi.org/10.36487/ACG_rep/1263_17_Engels (https://papers.acg.uwa.edu.au/p/1263_17_Engels/) Abstract: CODELCO is considering the implementation of high density tailings management at their Chuquicamata mine in northern Chile for its long term disposal plan. To achieve this, CODELCO commissioned the design, construction and operation of a 70 tonne/day pilot plant, fed by existing tailings. The testing programme was completed in May 2011 and consisted of laboratory rheological and characterisation assessments, pipe loop testing, beaching trials and analyses of deposition behaviour for solid contents ranging from 57–68% (w/w). This paper describes the characteristics of the pilot plant, the testing programme, the beach trial analyses and the resulting beach profile predictions based on the Stream Power theory. CODELCO also used other predictive beach slope methods, such as the Equilibrium Slope concept, which are not discussed in this paper. The final beach profile for design will be selected after an expert analysis of all methods has been completed.