Case Study: Gold Mining

Birds eye view of a gold mine


In gold mining, the crushed ore is irrigated with a dilute alkaline cyanide solution. The solution containing the dissolved precious metals (pregnant solution) continues percolating through the crushed ore until it reaches the liner at the bottom of the heap, where it drains into a storage (pregnant solution) pond.

Heap-leaching solution pools must be covered to prevent the destruction of waterfowl. Originally, netting was used but they are expensive to maintain, damaged regularly in winter storms and don’t camouflage the liquid surface sufficiently.


A floating layer of Euro-Matic Bird Balls™ is a perfect solution to successfully camouflage the open water surface from waterfowl who fail to recognise the ponds. The balls rise and fall with changing liquid levels and easily accommodate objects such as floating pump barges or aerators.

Fluid-loss through evaporation

Water is a precious commodity, especially for miners working in mountainous or inaccessible locations. Even a single layer of bird balls automatically arrange themselves into a close-packed formation to cover 91% of the liquid surface reducing the penetration of sunlight and thus the evaporation of the liquid. Due to the insulation properties of the Bird Balls, the operating temperature of the liquid can easily be maintained during wintertime.


Bird Balls™ are 100mm diameter UV-stabilised black hollow plastic balls, manufactured in High-Density Polyethylene. The balls are fully reusable, e.g. to cover another pond after the original site of cultivation has become uneconomic.

Maintenance free

Unlike netting, Bird Balls are a one-time and final solution. They are easy to install and only need to be poured onto the water surface from the packaging. Compared to netting, wind and snow do not affect the floating Bird balls.

Surface coverage

Euro-Matic has over 30 years of experience in the industrial manufacturing of hollow plastic balls.

The nominal weight of a standard Euro-Matic Bird Ball is 40g and the diameter is 100mm. For one square meter, the needed quantity is 116 balls. If the surface is exposed to higher wind speeds, we recommend the heavier 240g water-filled Bird Balls.

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