Experimental Study on X-ray Pre-concentration—Flotation of a Barite Ore in Guizhou

A barite ore in Guizhou contains 70.82% BaSO₄ with dolomite and feldspar being the main gangue minerals. The grain size distribution of barite is extremely uneven, and the association between barite and gangue minerals is complex. Beneficiation tests revealed that the gravity separation was not effective. As a result, the process flow of "particle classification—X−ray pre−concentration—flotation" was adopted. The X−ray intelligent separator was applied in pre−concentration operation to remove gauge particles for −30+15 mm of the raw ore, resulting in a discarding rate of 11.07%. The pre−concentration concentrate combined with −15 mm particle size samples was treated by the flotation process of one roughing and three cleanings under the grinding fineness conditions of −0.075 mm 90%. The separation indexes of barite concentrate with a BaSO₄ grade of 92.93% and a comprehensive recovery of 83.51% was finally obtained. The density of the concentrate was 4.34 g/cm³, meeting the standard for a special grade weighting agent for drilling fluid. Compared with the conventional process of "grinding—flotation", the X−ray pre−concentration process improved the concentrate grade by 1.11 percentage points and reduced the processing capacity of grinding and flotation operations without affecting the final concentrate recovery rate. Hence, the pre−concentration technology exhibits good promotion and application value.