PASTE & TAILINGS
seen in paste backfill systems. Hydraulic piston pumps( complete with poppet valves) or piston diaphragm pumps are primarily used for paste backfill applications. Typically, these pumps deliver between 50 to 150 m ³/ h of cemented paste to the underground stopes at delivery pressures between 5,000 to 12,000 kPa.”
Recently implemented paste pumping systems are pushing boundaries with increased flow rates up to 200 m ³/ h and pump pressures up to 15,000 kPa. PD pumps create fluctuations in the discharge flow rate due to the reciprocating movement of the pump pistons. These flow fluctuations cause transient pressure surges within the UDS, potentially causing fluctuating loads and hydraulic hammering. The magnitude of these loads has direct bearing on the size and quantity of the pipe supports, the pipe wall thickness, and overall safety of the UDS.
Paterson & Cooke engineers use a commercial software package to analyse transient pressures and forces in pipeline systems. This tool effectively models water, slurry or paste flows in complex pipeline systems, accurately predicting the transient pressures and forces during unsteady events such as pump trips, valve closures, and rupture disc releases. The software facilitates an in-depth assessment of a pipeline system’ s reaction to the unsteady flow caused by the normal cyclic operation of a PD pump.
“ Transient analysis of a pipeline is recommended if rapid changes in flow are expected in the system. These changes in flow could be caused by upset conditions such as a power failure, accidental valve closure, or a rupture disc event, or they could be caused by normal operations such as slurry batching, start-up and shutdown, or flow variations from a PD pump.”
Flow curves of several industry leading PD pumps were analysed to determine the expected transient pressures and forces in a typical UDS.“ As demonstrated in this study, the unsteady flow from normal cyclic operation of a PD pump can cause large transient pressures and forces in the UDS. Three hydraulic piston pumps and a single piston diaphragm pump( with and without a functioning dampener), representing a range of possible operating modes, were investigated. The analysis showed that although each of the PD pumps was specified to deliver 100 m ³/ h of paste at 7,500 kPa, the maximum transient forces produced by the PD pumps varied greatly. Procurement of a PD pump that produces significant transient pressures would either require a sturdier UDS and associated pipe supports or would necessitate operating with an inferior paste recipe with increased binder content. Both outcomes would negatively impact a project both in terms of
cost and operability.”
Although the UDS can be designed to handle relatively high transient forces, the authors say that additional complication of fatigue failure caused by cyclical loading from the PD pump also needs to be considered.“ Significant cyclical loading of the UDS will eventually lead to fatigue failure of the pipeline, the supports, and the couplings. PD pump pressure measurements must be completed with high-speed pressure transducers. If the data acquisition equipment used is unable to accurately measure the rapidly changing pressure in the system, this will lead to false conclusions regarding the performance of the PD pump’ s dampening system. The transducers used to measure transient pressures should be
READY TO LEVEL UP YOUR TAILINGS TREATMENT?
Increased operational availability, optimized plant efficiency, and safe dry stacking are possible with one of the broadest portfolios in tailings treatment, including
• filter and belt presses,
• drum and disc filters,
• vacuum belt filters,
• thickening solutions,
• plate-integrated sensor
• solutions( LENSER i-Plate)
• digital solutions, and more.
andritz. com / separation lenser. de / en
Discover efficient dewatering solutions for sustainable mining operations
GET MORE INSIGHTS AT OUR EXPERT TALKS AT PASTE 2026.
K. SCHROEDER on technology comparison( drum filter vs filter press) of red mud filtration
B. FISCHER on optimizing tailings filtration in filter presses capable of a data acquisition rate faster than or equal to 1 kHz.”
The lessons laid out in the paper Paterson & Cooke says are applicable for projects moving into implementation, or brownfield operations with PD pump dampening systems that are either ineffective or not functional.
For the full paper see Correia, LDC & Jacobs, J 2024,‘ Effect of paste pump performance on the transient pressures and forces in an underground distribution system’, 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. 441-452, https:// doi. org / 10.36487 / ACG _ repo / 2455 _ 35
MEET US AT PASTE
LISBON, PORTUGAL, 14-16 APRIL
International Mining | MARCH 2026 57