Barite Beneficiation

Barite is the primary, naturally occurring, barium-based mineral. Barium, atomic number 56, derives its name from Greek and means heavy. Barite is also known as baryte. The primary countries in which commercial deposits of barite are currently found are the United States, China, India and Morocco. Barite’s high density and chemical inertness make it an ideal mineral for many applications.

The chemical formula for barite is BaSO4. It has a high specific gravity of 4.50 g/cm3. Its Mohs hardness is 3.0 to 3.5. Barite, which may be found in a variety of colors including yellow, brown, white, blue, gray, or even colorless, typically has a vitreous to pearly luster.

Barite may be found in conjunction with both metallic and nonmetallic mineral deposits. To be economically viable for extraction, barite usually needs to be the predominant material in a deposit. The types of deposits in which it is normally found include vein, residual, and bedded. Vein and residual deposits are of hydrothermal origin, while bedded deposits are sedimentary.

Major deposits in the United States have been found in Georgia, Missouri, Nevada and Tennessee. In Canada, the mineral has been mined in the Yukon Territory, Nova Scotia and Newfoundland. In Mexico, barite deposits have been discovered in Hermosillo, Pueblo, Monterrey and Durango.

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The overwhelming majority of the barite that is mined is used by the petroleum industry as a weighting material in the formulation of drilling mud. Barite increases the hydrostatic pressure of the drilling mud allowing it to compensate for high-pressure zones experienced during drilling. The softness of the mineral also prevents it from damaging drilling tools during drilling and enables it to serve as a lubricant. The American Petroleum Institute (API) has established specifications for the use of barite in drilling mud.

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Dry Beneficiation of Barite

STET has both pilot scale and commercial experience processing barite to remove gangue such as silicates, iron and alumina. Low grade barite with a specific gravity between 3.5 – 4.0 has been successfully upgraded using the STET process to product API grade barite.

STET can demonstrate that the dry electrostatic separation process offers many advantages over traditional wet processing methods (flotation) including:

  • No water consumption. The elimination of water also eliminates pumping, thickening and drying, as well as any costs and risks associated with water treatment and disposal.
  • No wet tailings disposal. Recent high-profile failures of tailings dams have highlighted the long term risk of storing wet tailings. By necessity, minerals processing operations produce tailings of some sort, but the STET electrostatic separator tailings are free of water and chemicals. This allows for easier beneficial re-use of the tailings, for example barite tailings may be used in cement manufacture. Tailings that do need to be stored can be mixed with a small volume of water for dust control.
  • No chemical addition required. Flotation chemicals are an ongoing operating expense for mineral processing operations, and may impact performance of barite in drilling mud use.
  • Suitable for processing fine powders. API grade barite is 97% passing 75 microns, and therefore contains significant fines.
  • Lower investment cost (CAPEX) and lower operating cost (OPEX).

Disrupting a new industry is always a challenge. ST Equipment & Technology and Ramadas Minerals Pvt. Ltd. in India understand this challenge well. Ramadas Minerals contacted STET to perform testing of a low grade barite / quartz sample produced at the APMDC barite mine in Andhra Pradesh, India. The material was a low grade tailings product from the mining process. It contained too much silica to be sellable as a high SG barite product, and was being produced in large volumes. What was needed was a process to transform the mining waste to usable product. Wet processing (flotation) was one alternative technology being considered.

Testing at the STET pilot facility demonstrated excellent separation results for the barite powder. The STET separator was able to achieve the goal of +4.20 SG barite through a single separation step.

The STET separator was fit into the existing building, which was originally designed to house a flotation facility. The STET separator installation resulted in significant savings of space, in relation to the previously designed flotation facility. In addition, a substantial reduction in capital and operating cost was realized.

Contact STET to learn more about dry processing of barite.

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