Solar Pump Systems for Gold Mine Backfill and Paste-Fill Mixing Water

Introduction

Underground gold mines do not leave voids behind them—once a stope is extracted, it is refilled with paste or cementitious backfill so the ground above stays stable and the next level can be mined safely. Mixing that backfill takes a steady supply of water, often deep underground, far from any power. Running a diesel pump down a shaft is awkward and fuel-hungry; a solar pump at surface, feeding a mixing plant or a shaft-delivered line, is cleaner and cheaper. This article covers solar pump systems for gold-mine backfill and paste-fill mixing water, from specialists at KINBO.

The Backfill Water Duty

• Mix water—paste and cemented fill are made with a precise water-to-solids ratio; too much or too little water ruins the set and the ground support.
• Continuous while filling—a stope fill can run for hours, so the supply must be steady and interruptible only by design.
• Source to plant—water is usually drawn from a surface bore or tank and delivered to the mixing plant, then pumped (or gravity-fed) down the shaft to the fill point.
• Volume—scales with mining rate; a busy underground mine can use significant water per shift for backfill alone.

Selecting the Backfill Water Pump

• Centrifugal pump—the default for moving bulk mix water at the pressures a shaft column or long line needs.
• Pressure for shaft delivery—if water is pumped down a riser, size for the full column head; our high-head guide covers the head math.
• Water quality—backfill water is often recycled or slightly turbid; pick abrasion-resistant wet-ends (our abrasive-water guide).
• Control—a VFD-style solar controller holds mix pressure as the array output varies, protecting the ratio.

Solar Drive and Delivery

• Surface array—the pump sits at surface on the source; the solar array and battery serve it there, avoiding any electrical equipment underground.
• Buffer tank—an elevated tank decouples solar pumping from the fill schedule, so a cloudy spell never stops a stope from being filled.
• Hybrid backup—where fill must run regardless, a hybrid controller tops up from a small generator only when the buffer is low.

Solar vs Diesel Backfill Supply

Factor	Diesel Backfill Supply	Solar Backfill Supply
Energy cost	Per run-hour, perpetual	Zero after install
Underground safety	Diesel plant underground is undesirable	All equipment at surface
Logistics	Fuel to shaft collar	One-time install
Best fit	Grid-connected mines	Off-grid / underground mines

Keeping fuel and engines out of the underground environment is itself a safety win; our cost analysis quantifies the saving.

Frequently Asked Questions

Can solar deliver water down a shaft?

The pump stays at surface on the source; it delivers water through a riser or line to the underground mixing point. Size for the full column head so pressure is maintained at depth.

What about the water ratio?

A VFD controller and buffer tank hold the delivery pressure steady, so the mixing plant gets a consistent supply and the water-to-solids ratio stays in spec.

Does this need to run at night?

If fills run 24/7, add a battery or hybrid; otherwise a buffer tank carries the fill through cloud and a daytime-only mine needs no battery at all.

Can recycled water be used?

Yes—backfill often uses recycled or turbid water; specify abrasion-resistant wet-ends and a screen so the pump survives the solids.

Related Articles

• Solar Pump Selection for Deep Borehole Water Supply
• Solar Pump Selection for Abrasive and Sediment-Laden Water
• Hybrid Solar-Diesel Pump Systems for Gold Mines
• Explore KINBO Solar Pump Products

Get a Solar Backfill-Water Pump

Share KINBO your backfill rate, water source, required delivery head (including any shaft column) and water quality, and we will specify a solar pump with the right buffer and control to feed your gold-mine filling off-grid and safely. Contact our team for a tailored quote.

Published by KINBO · September 23, 2026 · Category: Application Cases