Manfredini & Schianchi proposes solutions for the processing and milling of barytes.
Thanks to technology based on the combined use of leading-edge Manfredini & Schianchi machines, it is possible to mill baryte, used for oil exploration, in compliance with the standards of the API (American Petroleum Institute). Thanks to this milling technology, one can exploit the amounts of mineral that are usually discarded on account of them being classified as inadequate from a physical point of view.
Baryte is a mineral consisting of barium sulfate (Barium, BaSO4) with a medium low hardness (3 of the Mohs scale) and an average specific weight of 4.5 kg/dm3. This mineral is mainly used in the oil industry as weighting agent for mud resulting from drilling (thanks to its high specific weight), to facilitate drilling and to reach petroleum wells.
Reference standards relating to processing of baryte used for oil and gas exploration are issued by the American Petroleum Institute (API). These standards establish limitations for the specific weight of this material, which particularly important owing to the mineral's use as weighting agent for drilling mud, and for particle size of milled baryte for this use.
Currently, parameters established by standards are as follows:
Minimum specific weight: 4.2 kg/dm3
Residue > 75 µm: 3.0% max.
Residue < 6 µm: 30.0% max.
Dry milling of barytes
Let us examine two samples of baryte, each characterised by a different specific weight (4.1 kg/dm3 and 4,2 kg/dm3), and subject to milling in a single pendular mill: the result of milling will be material with an extremely fine particle size and with a different apparent density (i.e. calculated on the milled material and not on 1 dm3 of ideal material) of one type of baryte (initial specific weight of 4.1 kg/dm3) with respect to the other (initial specific weight of 4.2 kg/dm3).
This difference makes baryte with an initial specific weight of 4.1 kg/dm3 not useable for oil drilling. To solve this issue and allow for exploitation of the enormous reserves of baryte with a specific weight of 4.1 kg/dm3, Manfredini & Schianchi offers a combined milling system, consisting of a Hammer Mill for rough milling and a Pendular Mill for finishing.
This system is capable of producing material with a final particle size that complies with the current API standards (i.e. Residue > 75 µm: 3.0% max.), but with a more even particle size distribution. By adopting this system, if baryte with a specific weight of 4.1 kg/dm3 is milled, the resulting particle size curve is composed of about 12% of particles < 10 µm and 100% smaller than 75 µm: the specific weight of material with these particle sizes is identical to that of baryte with an initial specific weight of 4.2 kg/dm3 milled using only a pendular mill.
The combination, suggested by Manfredini & Schianchi for baryte, of a Hammer Mill for rough milling and a Pendular Mill for finishing will allow you to obtain 100% of material with a particle size of < 75 µm but with a more even particle size distribution and less ultra fine material. This will make baryte having a specific weight of 4.1 kg/dm3 suitable for use in the oil exploration industry.
Barite 4.1 only pendular mill
Barite 4.1 primary hammer mill + finishing pendular mill
Apart from these results, which increase the potential use of large reserves of materials that could otherwise not be exploited, the system consisting of a Hammer Mill for rough milling and Pendular Mill for finishing offered by Manfredini & Schianchi can accept material of large sizes (up to 200 - 250 mm), even containing impure particles.
Both the Hammer Mill for rough milling and Pendular Mill for finishing offered by Manfredini & Schianchi can be fitted with thermal devices for handling issues relating to materials with a high moisture content.