Size Reduction Combined with Other Operations

Size Reduction Combined with Other Operations. 20-15... 

SIZE REDUCTION COMBINED WITH OTHER OPERATIONS... 

Ball mills or tube mills can be operated in closed circuit with external air classifiers with or without air sweeping being employed. If air sweeping is employed, a cyclone separator may Be placed between mill and classifier. (The principles of size reduction combined with size classification are discussea under Characteristics of Size Classifiers. ) Likewise other types of grinding mill can be operated in closed circmt with external size classifiers (Fig. 20-12), as will be described at appropriate places on succeeding pages. However, many types of grinders are air-swept and are so closely coupled with their classifiers mat the latter are termed internal classifiers. 

Mixing can also be done in combination with other unit operations, such as agglomeration, size reduction, particle coating, and chemical reaction, to name a few. Often, selection of an appropriate unit operation (e.g., grinding, agglomeration) can reduce the cost of the process by combining two unit operations. 

---