B02C17/1845

Methods for preparing and compositions including untreated and surface-treated alkaline earth metal carbonates

Methods for preparing and compositions including untreated and surface-treated alkaline earth metal carbonate particulates are described. For example, a method for processing alkaline earth metal carbonate may include introducing alkaline earth metal carbonate into a stirred media mill, and dry grinding the alkaline earth metal carbonate in the stirred media mill to produce an untreated alkaline earth metal carbonate particulate having certain characteristics. In some examples, the method may include introducing carboxylic acid and/or carboxylic acid salt into the stirred media mill, and dry grinding the alkaline earth metal carbonate and the carboxylic acid and/or carboxylic acid salt in an integrated dry grinding and surface-treating process in the stirred media mill to produce a surface-treated alkaline earth metal carbonate particulate. In some examples, heating may be added during the dry grinding process.

Ultrafine nepheline syenite

A useable particulate nepheline syenite having a grain size to provide an Einlehner Abrasive Value of less than about 100 is described. The particulate nepheline syenite is generally free from agglomeration and moisture free. At least 99% of the nepheline syenite particles have a size less than 10 microns.

Methods for reducing moisture content in alkaline earth metal carbonates

Methods for reducing moisture content of alkaline earth metal carbonate may include introducing alkaline earth metal carbonate having a moisture content ranging from about 0.1% by mass to about 10% by mass into a primary crusher and operating the primary crusher to obtain alkaline earth metal carbonate particles having a top cut particle size d.sub.90 of 90 microns or less. The method may also include introducing the particles into a primary grinder and operating the primary grinder to obtain reduced-size alkaline earth metal carbonate particles having a median particle size d.sub.50 of about 60 microns or less. The method may further include introducing the reduced-size particles into a classifier mill and operating the classifier mill to obtain further-reduced-size alkaline earth metal carbonate particles having a median particle size d.sub.50 of about 12 microns or less, and a moisture content of about 0.15% by mass or less.