What desliming equipment are there in placer gold mines?

August.14,2023

The placer gold ore washing operation includes three processes of crushing, screening and desliming. It is a very important and necessary operation before the placer gold ore is sorted. The reason why this operation is important is that it not only breaks and separates the mud and sand, but also removes the gold particles adhering to the surface of the gravel, and once a large amount of gold-free gravel can be screened out, it can be discarded directly; the general yield can be It reaches 40%-50% of the ore, and at the same time, most of the slime is removed.

In placer gold sorting, desliming, like removing large gravels, is also a very important preparatory operation. Materials less than 0.1mm in placer gold generally do not contain gold or contain very little gold. For example, gold less than 0.1mm in placer gold in Hunchun Gold Mine only accounts for 0.15%, while the same-sized ore slime accounts for 13.77% of the original ore sand. This kind of gold smaller than 0.1mm is commonly known as floating gold, which is difficult to recover during the sorting process.

In the placer gold ore dressing plant, always try to remove the slime less than 0.1mm in advance. Desliming equipment commonly used in production has desliming buckets of various specifications. However, the chute gold separation allows wide material particle size and large processing capacity, so the chute does not desilt before separation.

According to the washability characteristics of placer gold ore, vibrating screens, cylinder screens, hydraulic flushing plate sieves and other equipment are generally used to complete ore washing, crushing and screening operations.

Screening operation can remove 20%-40% of waste rock, even up to 50% of waste rock (gravel, pebble), which is an indispensable operation for placer gold beneficiation. The determination of reasonable screening parameters must be based on the determination data of the particle size composition of gold in raw ore sand.

At present, the sieve hole selected by placer gold in my country is generally 10-20mm. If a fixed chute is used as the roughing equipment, the sieve hole can be larger, but not more than 60mm. Most of the screening equipment in fixed dressing plants are grid screens and vibrating screens, while cylinder screens are used in gold dredging ships. Flushing water on the sieve can not only improve the screening efficiency, but also further break up the slime, so the screening operation of placer gold is mostly water sieving. The flushing water volume of the water screen should be determined according to the ore washing requirements, and meet the concentration requirements of the sorting operation in the next stage.