Pyro processing Lime hydration systems

Pyro processing Lime hydrators With over 100 years of experience in the minerals processing industries — the lime industry in particular — Metso has the resources and the expertise to design and supply a lime hydration system that best meets the specific requirements of each particular application. Lime hydration process The lime hydration process is one in which lime is combined with a proportional amount of water at a controlled rate. The chemical reaction that takes place between the lime and water (shown below in its simplest form) is an exothermic one, through which a significant amount...

1. Duplex mixer — This is the first chamber into which both lime and water are introduced. The unit is of carbon steel construction and is equipped with two paddle shafts for mixing. The unit includes a variable speed drive. 2. Seasoning chamber — This is the second system chamber in which the lime/water mixture is processed. The unit is of carbon steel construction and is equipped with a single paddle shaft for additional mixing. The unit is sized to provide a residence time sufficient for completing the hydration reaction. Lime feed from weigh belt feeder Process water 3. Baghouse collector...

The paste or slurry of lime and water that forms in the mixer discharges into the seasoning chamber where it is retained for the proper length of time to complete the hydration reaction. The seasoning chamber is a horizontal, semi-cylindrical vessel in which a shaft fitted with arms and paddles slowly rotates to mix the mass of hydrating lime and slowly advance it to the product discharge. Retention time in the seasoning chamber can be adjusted, to some extent, by adding or removing plates that make up a variable height overflow weir at the discharge end of the seasoning chamber. The actual retention...

There is a similar process in which an excess amount of water is used to hydrate the lime. This process is referred to as lime slaking and the product discharged from a lime slaker takes the form of a slurry. Information specific to Metso lime slakers is available separately. There is yet a third type of lime hydration process that involves lime containing a significant amount of magnesium, which is commonly referred to as dolomitic lime or simply dolime. This process also produces a dry, powdery hydrate, but because the magnesium oxide present in the dolime does not easily combine with water,...

Lime feed bin and enclosed weigh feeder Duplex mixer and seasoning chamber The figure below shows a typical stack-up of a standard Metso hydration system with a nominal hydrate production capacity of 8.5 STPH. 6 Lime Hydration Systems

Lime Hydration Systems 7

Expect results It is our promise to our customers and the essence of our strategy. It is the attitude we share globally; our business is to deliver results to our customers, to help them reach their goals. metso Metso Minerals Industries, Inc., 350 Railroad Street, Danville, PA 17821, USA, tel +1 570 275 3050, fax +1 570 275 6789, www.metso.com