Grohs, K, Liu, M, Satriawan, A, Kunadi, S & Simanjuntak, B 2024, 'Application of wet tailings pressure filtration for filtered tailings stack and co-disposal with mine waste at various sites including upstream and downstream of the tailings storage facility', in AB Fourie & D Reid (eds), Paste 2024: Proceedings of the 26th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 77-94, https://doi.org/10.36487/ACG_repo/2455_05
(https://papers.acg.uwa.edu.au/p/2455_05_Grohs/)
Abstract: The Martabe Gold Mine is located in the district of Batang Toru in the Province of North Sumatra, approximately 40 km southeast of the coastal town of Sibolga. The carbon in pulp plant was commissioned in 2011 with a nameplate capacity of 5.5 mtpa. With the recent upgrade in 2022, whereby a Verti-mill was installed in the comminution circuit, this has increased the annual plant capacity to 7.0 mtpa. 
Given the significant increase in plant annual throughput, additional tailings capacity is required to sustain this increase for the life of mine. With challenging terrain and a lack of suitable valleys for construction of a tailings storage facility, this has prompted the application and adoption of a filtered tailings stack and codisposal approach for containing tailings and mine waste as various sites at Martabe.
Preliminary laboratory testing using a pressure unit from Diemme–Aqseptence has shown that the tailings slurry can be filtered to attain the required critical moisture content of between 12–14% w/w with good cycle times at 12–13 minutes. Following from the laboratory test, a 0.3 t/h pilot plate and frame pressure unit was hired and tested on plant tailings slurry for over 12 months. The pilot plant with the blow and squeeze function included was able to replicate the moisture results attained from the laboratory test.
With the success of the pilot pressure filtration testing and its suitability to be used for tailings filtered stack and with mine waste for co-disposal, PT Agincourt Resources engaged Ausenco to complete the feasibility study, followed by the design, engineering, construction and installation of two plate and frame pressure filters. The preferred vendor chosen to supply the filter equipment was Diemme–Aqseptence. The plant consists of two vertical recessed pressure plate filters rated at 235 t/h for each unit. The GHT-2500 F26 filter plate and cloth are made of polypropylene capable of withstanding the high filter pressure rated at 16 bar. Each unit consists of 132 recessed plates with two end plates with a plate size of 2,640 mm in width and 3,050 mm in length with a 50 mm chamber thickness. The plant is expected to be ready for commission by June 2024.
Site selection was dominated by proximity to the planned disposal site, being adjacent to the haul road intended to transport the mine waste and filtered tailings for co-disposal, which improves the geotechnical strength of the placement structure and close to the process plant for ease of services extensions and slurry tailings delivery. The zone was also a low grade extension of the main Purnama pit, which provided some financial return on the costs of excavation of the proposed filter plant site.

Keywords: gold processing, pressure plate and frame filter, tailings filtered stack, waste co-disposal, filtered cake moisture