Sensor-based sorting technology recovers barite from barite ores
Publication Date: 2015-May-29
The IP.com Prior Art Database
This paper relate to methods of barite ore sorting. It describes methods that uses sensor based sorting to separate valuable barite-rich rocks in the ore from barite-poor or one consisting of different minerals. The method includes steps of mining, primary grinding, and screening to sensor-based sorting resulting in a product ore that contain pre-determined amounts of barium sulfate mineral. The process includes the use of X-ray transmission sensor-based sorting technology for processing of barite ores to separate barium sulfate mineral component from other minerals and to increase specific gravity of the ore.
Barite, or barium sulfate, can be found in many areas around the world; however, pure form is fairly rare. It is a naturally occurring mineral that is heavy, relatively soft, inert, non-magnetic, non-toxic, temperature stable up to approximately 1,500 deg. C and practically insoluble in water or oil (3). All these properties make barite unique and sometimes irreplaceable for use for several specific purposes.
According to the data of The Barytes Association, the Oil and Gas Industry is the biggest consumer of barite. The Oil Industry uses 80% of all barite mined in the world and 95% of barite mined in the US. Other major consumers include chemical industries that provide barium meals materials for electronics, TV screen, glass, ceramics and medical applications and fillers for cars manufacturers, rubber and paint industries and materials for radiation shielding (1).
In the Oil Industry barite is used mainly for drilling fluids and American Petroleum Institute (API) established specifications for such use. Along with several other requirements, API standards mandate defined range of particle size and specific gravity (SG) for ground barite. Ground barite should have SG 4.1 if used for land operation inside the US and 4.2 if used offshore (2). On practice, the vast majority of mined ore does not directly satisfy these criteria and barite ores need to be processed or beneficiated to remove contaminates and then ground to satisfy API specifications and be called API barite.
Barite is extracted from the earth in many cases by surface and sometimes by underground mining. Extraneous minerals are then need to be removed and ore need to be properly sized that is usually done by physical processing methods. After ore is extracted (Figure 1), it is, first, crushed and sized and then jigged or separated or sorted by other methods to achieve required SG of the product that next is transported for blending and final grinding and sizing.
Figure 1. Extracted barite ore prior to the first crushing and sizing.
Sorting is the “first line of defense” in the process of manufacturing of API barite from ore. Generally, sorting serves the following purposes in ore processing:
• Concentration - to produce finished product.
• Pre-concentration - to upgrade the ore and produce a smaller bulk for future processing.
• Salvage - to make acceptable feed for the next processing step from low or marginal grade crude ore deposit.
Because the sorting can be done at or near a mine, usually, after first crushing and screening, it significantly reduces transportation, therefore, only product ore that is ready for blending and grinding is transported. Many environmental effects, emissions and costs can be optimized depending on this close-to-the-mine placing of this processing plant. Furthermore, the sorting itself is desired to be conservative in terms of need for water, energy, space...