A description referring generally to fig1 the preferred apparatus 10 of the invention comprises a housing 12 including first and second spaced apart plates 12 a 12 b affixed to one another in spaced relation by a plurality of generally radially extending ribs 14 in addition plates 12 c fig7 are welded between plates 12 a and 12 b to form a grinding chamber within housing 12 as will be understood from the description below housing 12 generally includes a material inlet 16 and a ground material outlet 18 a base 20 having a plurality of feet 22 supports apparatus 10 feet 22 preferably have a leveling capability a drive 30 generally comprising a belt 32 and a wheel 34 which may be driven by a suitable electric motor not shown such as discussed in the 39 610 patent having sufficient power for the particular application drive 30 couples to a rotatable shaft 36 extending into a grinding chamber 40 a material distribution wheel 42 is coupled with rotatable shaft 36 and includes a plurality of generally radially extending blades 44 adapted to distribute material falling into grinding chamber 40 through inlet 16 in a radially outward direction upon rotation by drive 30 a rotating grinding plate 50 shown for clarity as a dash dot line in fig1 is also coupled with rotatable shaft 36 a pivoting and linearly movable door 52 carries a stationary grinding disc or plate.