A mine or quarry supplies gold-bearing ore to the gold mill where the ore is crushed, graded, sorted, and smelted into ingots. Crushed to sand, the ore goes to the gravity table where one of the sorting processes takes place. At this stage, the control over the employees was not very strict and as a result... the mill experienced a gold shortage of 7%. In other words, out of a kilogram of gold from the conveyor, only 930 grams made it to the final stage. More than a ton of gold "vanished" annually. A ton of gold costs USD 57,000,000. With the global gold production amounting to 3,000 tons per year, 20 tons of gold get siphoned off (USD 1 billion) – and this is at the plant, let alone the mine and transportation.
Attack Scenario 1: The malcontents would sometimes put a stick on the gravity table to build up a pile of gold sand and then scoop the sand with their hands straight into a pocket. Then they would put it in a handkerchief and make a tricky gear of yarn and nylon stockings to transport the sand through the ventilation system to the outside. In slang, this is called "letting the horse through the vent.”
Attack Scenario 2: The perpetrator would hide a bucket with gold sand in a tank with chemicals to be taken out of the security perimeter.
Attack Scenario 3: In the smelting shop,
doré alloy would inadvertently be spilled on some item that has been deliberately put there by a steelworker, and the perpetrator would go home where a "golden shoe" that left the factory via ventilation would be waiting for him.
Solution: We installed 17 IP cameras and 3 servers with specialized software. The solution cost USD 800,000. The project roll-out took 7 months. It involved six specialists.
The video analytics software could recognize 20 target scenarios of “non-standard behavior”, such as when the operator’s hand is in the wrong place at the gravitation screener; the operator is not holding a special brush; the operator is touching the gold-accumulating box; the operator is sealing the gold concentrate carrier in a wrong way; etc.
Result: The installation of the video analytics system resulted in a loss reduction from 7% to 2%. It is still a mystery though where the remaining 300 kg of gold vanish yearly. Extrapolating these results from one enterprise to global gold mining, the implementation of video analytics could reduce the loss of gold 3–7 times, from 20 tons per year to 3–6 tons.