Rock salt is mined and going through a primary crushing underground to obtain pieces smaller than about 9 inches (23 cm).
The salt is then transported outside the mine to a secondary crushing area to reduce the particle size to about 3.2 inches (8 cm).
At this point foreign matter is removed from the salt, a process known as picking. Metal is removed by magnets and other material by hand. Rocky material may also be removed in a rotating metal drum with small holes in the bottom. Salt is dumped into the drum, breaks when it hits the bottom, and passes through the holes. The picked salt then goes to a tertiary crushing area to produce particles about 1.0 inch (2.5 cm) in size. If smaller particles are needed, the salt is passed through a grinder. If purer salt is needed, rock salt is dissolved in water to form brine for further processing. Otherwise the crushed or ground salt is passed through screens to sort it by size, poured into bags, and shipped to the consumer.
Application: Primary crushed salt rocks are further crushed in an underground mine prior to being further processed and are stored in large underground silos.
Challenges: The primary crushed rock storage silo is the initial stage in the production of salt, feeding a secondary crusher, and therefore needs to be monitored to allow smooth production upstream. Since the silo is underground, it is usually created by controlled explosions and the walls are not smooth, making accurate volume measurement of the stored salt rocks inside very difficult. Early detection of build-ups that form inside the silo is important to the end-user to allow timely maintenance to reduce risk of material collapse to the bottom of the silo, which could cause damage to the silo, the crusher and other mechanical parts. Rosemount 3D Solids Scanner's sophisticated mapping technology overcomes these challenges and provides actual real-time volume measurements of the stored material for these complex silos and, in addition, displays a 3D image of the stored content to allow early detection of build-ups.
Application: Smaller-sized secondary crushed salt rocks (approximately 2 cm in diameter) from the secondary crusher are stored in production silos allowing better control of the process.
Challenges: The secondary crushed rock storage silo is located outside the mine and feeds the finished material production process; therefore it needs to be monitored to allow a smooth production cycle. Early detection of build-ups that form inside the silo is important to allow timely maintenance that will reduce the risks of damage to the silo and of unexpected interruptions to production. Rosemount 3D Solids Scanner's sophisticated mapping technology answers all the needs by providing actual, real-time volume measurements of the stored material and, in addition, displays a 3D image of the stored content to allow early detection of build-ups.
Application: Ground salt is stored in large silos for shipment to consumers from various industries.
Challenges: The salt storage silos are wide (often exceeding 25m diameter) and the end-user faces constant difficulties trying to closely monitor the salt's inventory levels. Understanding the accurate volume of salt stored in each silo allows production optimization. The Rosemount Solids Scanner provides accurate, real-time volume measurements for any size of silo, and its 3D visualization tool allows the end-user to see how the material is actually distributed inside the silo, contributing to improved management and control over inventories and related costs.