IM 2020 September 20 | Page 53

PASTE & TAILINGS 2020 ABEL’s mine backfill solution Pump manufacturer provides example of how its piston diaphragm pumps can improve backfill slurry quality ABEL HMQ piston diaphragm pumps offer a solution for very challenging conditions Background Our client is a mining company involved in mineral exploration and exploitation. The mineral extracted is treated in a polymetallic processing plant, which operates 24 hours a day, 365 days a year. Mining is carried out by excavating primary and secondary stopes, which are subsequently backfilled with a slurry made of residues originating from the mineral treatment process. This results in a modern, highly efficient and environmentally friendly process. The product The process of metal extraction is accompanied by the accumulation of large quantities of tailings, sometimes used for refilling stopes no longer in use. Due to increasing environmental awareness, the handling of tailings from mining processes has become a crucial issue for every mining company nowadays. Even though they are a byproduct of the mineral concentration process, tailings do not have any real economic value. Thickening the tailings and adding cement to the mixture allows a high solid content backfill slurry to be obtained. The high resilience of the mixture significantly reduces both the environmental footprint and the risk of environmental damage. For an optimal backfilling of the mine with slurry, it is necessary to prepare a high quality, high solids content and resilient slurry without compromising its fluidity in the entire discharge pipework. The application Despite our client’s extensive experience in preparing backfill slurry, the process constitutes a new challenge, given that in previous mining operations, backfilling has always benefitted from the effect of gravity. The application requires the pump to convey a larger backfill cone so 100% of the mine can be backfilled and offer maximum operating safety. This is where the ABEL piston diaphragm pumps come into play as the solution for the handling of cemented backfill in the mine. In contrast to other conventional technologies for slurry backfill, these pumps are operated at a very lower cost – lower than the pumps our client was previously using. The solution When it comes to working under the requirements of mining applications, the equipment installed must guarantee a high degree of reliability and availability, and must also be suitable for challenging conditions, operating during long periods without interruption. ABEL HMQ piston diaphragm pumps represent the solution for very challenging work conditions. The introduction of the diaphragm as a means of separation between the slurry and the drive side of the pump allows the maintenance intervals to be significantly increased compared with those of equipment in direct contact with the cement. Main characteristics ABEL HMQ performance: up to 275 cu.m/h and up to 16 MPa. Advantages n Transfer of solids, pumping of fluids with solid content concentrations > 75% in terms of weight; n Pre-formed diaphragm: separation between slurry and drive; n Extra-large suction valves with a high degree of volumetric efficiency; n Yield stress > 200 Pa; n Strokes per minute are low and ensure a low mechanical wear; n Individual, customised case-by-case design and dimensioning. Thanks to these properties and design, the pumping equipment offers a long, useful lifetime and satisfies the particular requirements and needs of the backfilling application. Put simply, the process can’t stop. Therefore, ABEL closely cooperates with its clients and engineers on designing and defining a specific pump for the specific backfilling application by adapting its structural design to the specificities of a high density and high cement containing slurry. The use of pulsation dampers allows a continuous, gentle and low pulsation discharge of the slurry into the excavated stopes and entirely eliminates the risks linked to possible problems in the most critical component of the backfilling process: the pipework. IM SEPTEMBER 2020 Supplement | International Mining P1