Case Study: Gold Mining

Published on 7 April, 2017 at 9:37 pm

Problem

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 waterfowls. Originally netting was used but they are expensive to maintain, damaged regularly in winter storms and they don’t camouflage the liquid surface sufficiently.

Solution

A floating layer of Euro-Matic Bird Balls™ is a perfect solution to successfully camouflage the open water surface from waterfowls 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 sun light and thus the evaporation of the liquid. Due to the insulation properties of the Bird Balls, the operating temperature of the liquid can easily maintained during winter time.

Operation

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

Maintenance free

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

Surface coverage

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

Nominal weight of a standard Euro-Matic Bird Ball is 40g and a diameter is 100 mm. 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.