Introduction

CrIEM, acronym for “crystallizer with ion exchange membrane”, is a device that exploits the selective feature of the ion exchange membrane to perform selective reactions. In particular, with respect to the state of the art, it allows the formation of precipitates by means of reactive crystallization processes, exploiting Donnan Dialisys process.

Technical features

The present invention is a process to perform selective reactions to avoid direct mixing between two solutions and to minimize the effect of undesirable secondary reactions. According to the process of the present invention, it is possible to selectively “get in touch” the reactants of a reactive crystallization reaction present in two different solutions, avoiding direct mixing between the solutions themselves. Thus, the crystallizer is capable of carrying out controlled reactions, exploiting the characteristic of ion exchange membranes, even when in the solution there is the presence of competing ions (to the principal reagents) that can react in parallel reactions to the principal  one giving unwanted products.

Possible Applications

• Cristallization;
• Recovery of minerals from industrial or natural waste solutions;
• Separation of ionic species.

Advantages

• Use of any kind of alkaline reagent;
• Selective reactions due to the characteristic of ion exchange membranes;
• Controlled crystallization;
• High quality of the products;
• Modular system and adaptable to a large number of different operative conditions.