Gold extraction mining plant

Measuring Task

The underflow discharge from the thickener is pumped at a solids concentration of 50-60% to the center of two agitators arranged in series. The solution is introduced into the first tank to ensure that the slurry maintains a solids concentration of approximately 50%.

Instrument used

The gold extraction mining plant, jointly operated by Pan American Silver, is located in the Antofagasta region of Chile. The plant has a capacity of 4200 tonnes per day and employs a metallurgical process to extract gold from minerals. The process involves several stages, including a crushing-grinding circuit and agitation cyanidation leaching in tanks. The key goal of the process is to achieve the extraction of Doré metal using the Merrill Crowe process and subsequent smelting of precipitates.


In copper sulfide operations involving processes such as grinding, flotation, thickening, and filtering, density measurement has conventionally relied on the use of radioactive isotopes. However, there is currently a notable shift among users of this technology who are actively seeking alternatives. This shift is motivated by valid concerns regarding health and environmental regulations that govern the use of radioactive isotopes in such operations. The challenge is to test the Slurry Density Meter’s capabilities in contrast to that of the nuclear density meter to determine accuracy and reliability. The primary thickener is where the intentional performance test of the non-nuclear density meter is conducted.


Having a clear understanding of the potential risks and regulatory challenges associated with the nuclear density meter, the user exhibited a strong inclination towards adopting a safer alternative that would maintain operational efficiency and accuracy without compromise. Their primary objective was to identify a solution that would incorporate essential safety measures while guaranteeing dependable and precise measurements. This approach aimed to effectively address concerns related to radiation hazards while simultaneously meeting the requirements for optimal performance in their operational processes.

After this successful trial with the Slurry Density Meter, Pan American Silver is planning to remove the nuclear density meters, due to the implications it has on the health and safety of personnel, and environmental, transportation and safety permits.

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Get in touch with Rhosonics for further information about chemical concentration or density control. If you want to learn more about our applications, then please also check our client cases and webinars.

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