The benefits of autogenous grinding milling when processing the Fort a la Corne Kimberlites

Abstract Shore Gold Inc. (Shore) is presently designing a diamond processing plant for the Star and the Orion South kimberlite deposits in the Fort à la Corne area in central Saskatchewan. The first step in the plant is diamond liberation and occurs in the comminution circuit. Diamond liberation is the process of breaking up the kimberlite rock, as “gently” as possible. Essential to the diamond liberation process is that diamond damage must be minimized, particularly for the larger, high value diamonds.
The Southern African diamond mines traditionally use Jaw and Gyratory crushers as their primary comminution method. However, these diamond mines generally process the harder, competent kimberlite that is located in the diatreme zone as well as the root zone of the volcanic pipe. Softer kimberlite is typically located in and around the crater area of a volcanic pipe and it is this source of kimberlite that makes up the majority of kimberlite for both the Star and Orion South deposits. These softer kimberlites can be readily broken up using abrasion and attrition imparted by AG mills, this being the preferred method of comminution when minimizing diamond damage.
Keywords: AG mills, Kimberlite, Liberation, Saskatchewan, Diamond
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