Lithium hydroxide monohydrate and preparation method thereof

The invention refers to a dust-free lithium hydroxide monohydrate and a preparation method thereof, belonging to the technical field of lithium hydroxide. The technical problems to be solved by the invention are that wet LiOH.H2O has a problem of hardening and dry LiOH.H2O has a problem of dust explosion in the prior art. The invention provides a novel LiOH.H2O, that is, dust-free lithium hydroxide monohydrate without hardening. The lithium hydroxide monohydrate is a loosened granular wet product, wherein the content of water is less than or equal to 3.5%, and the surface of the lithium hydroxide monohydrate is coated with a little anti-hardening agent. The dust-free lithium hydroxide monohydrate is prepared by the following methods: (1) preparing a LiOH solution having a Li2O concentration of 70+-5g/l, and the concentration of SO42- is less than or equal to 15g/l; (2) evaporating the LiOH solution obtained in the step (1) until the ratio of liquid to solid is 1: (0.8-1.5); adding a little anti-hardening agent; uniformly stirring; separating and washing the mixture to obtain dust-free wet LiOH.H2O; and carrying out vacuum seal and packing the wet product, wherein the obtained product is not hardened within 3-5 months.