Barite mine process

Barite mine process

Commercial barite is mined from surface or near-surface deposits by open-pit or underground mining methods. The broken ore is trucked to the processing plant where it may be washed by log washer or trommel screen to remove adhering clay and low-grade fines before reduction by jaw or impact crusher to 25 cm or finer for further processing. The degree of further processing and concentration depends on the grade of ore, identified end use, and liberation size (i.e., the size at which the barite is essentially free of contaminating impurities). If a further size reduction is required, this can be accomplished by jaw crusher, impact crusher, cone crusher, or roll crushers.

The concentrated barite may be ground to final size specifications by roller mill, paddle mill, or other suitable unit. A 45-micrometre (μm) product is normally specified for drillmud barite; however, a much finer product may be required for other applications such as chemical and pharmaceutical preparations. Barite used for drilling petroleum wells must be finely ground so that at least 97% of the material, by weight, can pass through a 200-mesh (75-μm) screen, and no more than 30%, by weight can have an effective diameter of less than 6 μm, which is measured using sedimentation techniques. The ground barite must also be dense enough so that its specific gravity is 4.2 or greater, soft enough to not damage the bearings of a tricone drill bit, chemically inert, and contain no more than 250 mg/kg of soluble alkaline salts. A small percentage of iron oxide is allowable.