Handle bagged borate products with care. Avoid puncturing bags while using sharp instruments. A hole in a bag not only results in spillage but might expose the product to moist air, which can cause caking. Punctured bags also increase the potential for product contamination. For more information about the packaging and storage of bagged products:
With increasing demand and changes in industrial practice, many users of sodium borates and boric acid—particularly Neobor borax pentahydrate, Optibor boric acid, Dehybor anhydrous borax, and borax decahydrate—find it more economical to use bulk transfer.
Trucks and containers can typically ship a bulk load of 18 to 28 tons; railcars, 100 to 110 tons. Before converting to bulk shipment, we suggest that customers work with their supplier to determine the most appropriate transport system.
Gravity unloading is the typical choice, especially with products that tend to cake and form lumps under certain humidity and temperature conditions (eg, borax decahydrate). Gravity unloading is accomplished by discharging product directly from a rail hopper car to a pit located between the rail tracks. Customers should use an air-operated impact wrench to open and close the slide gate, which can bind with the build-up of product in the slide tracks. Product can then be discharged at a controlled rate from the track hopper, through an adjustable slide gate, to a mechanical conveying system, and then to a storage silo.
Pneumatic unloading is done by vacuum or combination vacuum-pressure techniques. Neobor and Optibor are nonabrasive, so this procedure can be used to easily convey these products directly from the car to the silo. A flexible hose with quick coupler is usually attached to a side port on the car; the other end is attached to permanent piping that runs parallel to the silo. This unloading method prevents the product from being exposed to the elements; the closed system eliminates the potential for contamination from outside sources.
Borax decahydrate contains a higher percentage of water than either Neobor or Optibor, making it more prone to caking. Therefore, although pneumatic unloading is possible, mechanical unloading is strongly recommended. If pneumatic unloading is used, gravity discharge the product through a double-finger crusher and into a holding bin before pneumatically conveying it to the silo.
A mechanical conveying system can consist of belt conveyors, screw conveyors, and centrifugal bucket elevators. Electric or air vibrators mounted near the discharge opening of the track hopper can facilitate discharge, if necessary. Mechanical systems should incorporate sealed transfer chutes or dust extraction.
Pneumatic conveying systems have the advantage of being dust-free. Neobor, Optibor, and borax decahydrate can be air conveyed by pneumatic pipe systems or air slides. Dehybor, because of its abrasive nature, requires the use of ceramic or hard-faced liners at specific points where abrasive wear is expected: elbows, transition pieces, and impingement surfaces in cyclones, diverters, and receivers.
If considering an air slide to convey borax decahydrate, use the same precautions noted for pneumatic unloading (gravity discharge through a double-finger crusher and into a holding bin before conveyance). Use only dry, cooled air and be sure to maintain air conveying temperatures below 95°F (35°C). Air conveyance is not recommended for locations that are frequently humid with high ambient air temperatures.