Pan mills

Mined clay with 22 percent moisture is broken up into pieces of less than 5 cm (2 in) in a rotary impact mill without screen, and fed to a rotary gas-fired lain for drying (see Fig. 20-58). The moisture content is then 8 to lOpercent, and this material is fed to a miU, usually a Raymond ring-roll mill with an internal whizzer classifier or a pan mill. Hot gases introduced to the mill complete the diying while the material is being pulverized to the required fineness. 

Sixty percent of refractoiy magnesite is made synthetically from Michigan brines. When calcined, this material is one of the hardest refractories to grind. Gyratoiy crushers, jaw crushers, pan mills, and ball mills are used. 

In the case of ware with less demanding requirements for mixture homogeneity (bricks, drain pipes, etc.), mixing is carried out with a pan mill which is suitable for the preparation of press mixtures as well as plastic bodies. As the treatment causes considerable entrapment of air in the mixture, it is usually linked up to a vacuum extruder where the mix has air removed, is kneaded and preformed or is given its final form. 

Sixty percent of refractory magnesite is made synthetically from Michigan brines. When calcined, this material is one of the hardest refractories to grind. Gyratory crushers, jaw crushers, pan mills, and ball mills are used. Alumina produced by the Bayer process is precipitated and then calcined [Krawczyk, Ceram. Forum Int., 67(7-8), 342-348 (1990)]. Aggregates are typically 20 to 70 pm and have to be reduced. The standard product is typically made in continuous dry... 

Mechanochemical processing has been used to conduct the esterification of poly(vinyl alcohol) (PVA) with maleic anhydride through stress-induced reaction by pan-milling (Scheme 8.5). In comparison with conventional methods for the esterification of PVA, this protocol is viable and environmentally friendly and can be an effective technique for the chemical modification of polymers. ... 

The solid-state mechanochemical milling using a pan mill was employed to devulcanize GRT (Xu et al., 1996). A decrease of the gel fraction and crosslink... 

Intermediate Crusher. A machine of a type suitable for size reduction from about 8 to 20 mesh, e.g. a pan mill or ball mill (note, however, that a ball mill can more properly be used as a fine GRINDER (q.v.)). 

Pan Mill. Term sometimes applied to an EDGE-RUNNER MILL (q.v.) but more properly reserved for the old type of mill (also known as a block mill) for grinding flint for the pottery industry. It consists of a circular metal pan paved with chert stones over which are moved heavy blocks of chert (runners) chained to paddle arms. 

Following the removal of co-minerals, either by hand or mechanically, mica is ground by various methods to give particles with top sizes ranging from 5 mm to 10 pm. In order of decreasing particle size, the methods of comminution used are hammer mills, pin mills, wet rod mills, wet pan mills and jet mills. Mechanical sieving is used to control particle size down to about 100 pm top size. Air classification is more effective for finer particle sizes. 

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