a) try to smelt dusts
                              in
 +---<-+-----+---<-+-----+---<-+->---+-----+->---------+->---+
tf1   tf2   tf3   tf4   if1    |    if2   tf5         tf7   tf6   out
 +->--pulv  wash  ther  bath   ^     +->-<-+-]   +->--chst  chst [-+---<-+
       +->---+-----+->---+----chst  furn  tf9   tf8   reg9  reg4  allo  pakd
                                     +->---+-----+     +-----+->---+-----+

b) don't smelt dusts
                              in
 +---<-+-----+---<-+-----+---<-+->---+-----+->---+-----+
tf1   tf2   tf3   tf4   if1    |    if2   tf5   tf7   tf8
 +->--pulv  wash  ther  bath   ^    furn  out-  chst  chst  
       +->---+-----+->---+----chst  chst   ^  \ reg9  reg4
                                    reg9->pakn -pakd-<-+

b2) b but try to smelt
replace out with +->--furn--out
                  \----------+


c) to build
       +-----+---<-+-----+---<-+---<-+-----+->---+-----+->---+
      tf2   tf3   tf4   if1          |    if2   tf5   tf7   tf8
 in->-pulv  wash  ther  bath         ^    furn  out-  chst  chst  
       +->---+-----+->---+-----+----chst  chst   ^  \ reg9  reg4
                                          reg9->pakn -pakd-<-+
machine
tf#   type

processing
universal pulverizer
1     ore
2     centrifuged
ore washing plant
3     crushed
thermal centrifuge
4     purified
chemical bath
if1   as needed

output
furnace
if2   as needed (centrifuged -> 10 nuggets)
5     dust
regulator (4)
6     small
regulator (9)
7     tiny
packager (dusts)

variant a
8     nugget
9     ingot
alloy smelter

variant b
regulator (9)
packager (nuggets)

variant b2
furnace

potential problems
chemical bath too slow for ? [fix: replace tf? by inverted if1]
furnace too slow for thermal centrifuge (and pulverizer in a) [fix: replace tf2 by inverted if2]
alloy smelter too slow for dusts (only a) [fix: if in front of pakd allowing unsmeltables (, or inverted and blocking smeltables)]
furnace too slow for dusts (only b2) [fix: if in empty path allowing unsmeltables (, or inverted and blocking smeltables)]