﻿34 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  port. 
  In 
  the 
  Old 
  Bed 
  workings 
  at 
  Mineville, 
  the 
  ore 
  is 
  removed 
  

   in 
  large 
  chambers 
  which 
  are 
  extended 
  downward 
  with 
  the 
  progress 
  

   of 
  operations, 
  as 
  the 
  main 
  mass 
  of 
  ore 
  lies 
  nearly 
  vertical! 
  The 
  

   chambers 
  are 
  of 
  great 
  size, 
  measuring 
  200 
  feet 
  or 
  more 
  from 
  roof 
  

   to 
  floor. 
  Timbering 
  or 
  other 
  artificial 
  support 
  is 
  not 
  required 
  in 
  

   the 
  Adirondack 
  mines, 
  and 
  little 
  trouble 
  has 
  been 
  experienced 
  

   from 
  caving. 
  The 
  workings 
  are 
  relatively 
  dry, 
  as 
  the 
  wall 
  rocks 
  

   are 
  nearly 
  impervious 
  to 
  water. 
  

  

  Concentration 
  of 
  the 
  magnetites 
  has 
  been 
  practised 
  since 
  the 
  

   early 
  days 
  of 
  mining 
  in 
  the 
  region. 
  As 
  early 
  as 
  1836, 
  according 
  

   to 
  local 
  records, 
  a 
  plant 
  was 
  in 
  operation 
  at 
  Palmer 
  hill 
  for 
  treat- 
  

   ing 
  the 
  ore 
  by 
  a 
  magnetic 
  process. 
  The 
  details 
  of 
  this 
  installation, 
  

   an 
  interesting 
  precursor 
  of 
  the 
  modern 
  plants, 
  have 
  unfortunately 
  

   been 
  lost, 
  though 
  it 
  is 
  hardly 
  probable 
  that 
  the 
  venture 
  could 
  have 
  

   been 
  successful. 
  A 
  wet 
  gravity 
  system 
  of 
  concentration 
  was 
  com- 
  

   monly 
  used 
  up 
  to 
  about 
  15 
  years 
  ago 
  when 
  the 
  magnetic 
  process 
  

   was 
  perfected 
  to 
  an 
  extent 
  that 
  made 
  its 
  introduction 
  feasible. 
  

   This 
  process 
  is 
  now 
  generally 
  recognized 
  to 
  be 
  well 
  adapted 
  to 
  the 
  

   Adirondack 
  magnetites. 
  

  

  At 
  present 
  there 
  are 
  six 
  concentrating 
  plants 
  in 
  the 
  region; 
  two 
  

   are 
  installed 
  at 
  Mineville, 
  two 
  at 
  Lyon 
  Mountain 
  and 
  one 
  each 
  at 
  

   Arnold 
  hill 
  and 
  Benson 
  Mines. 
  Another 
  plant 
  is 
  in 
  course 
  of 
  

   erection 
  at 
  the 
  Cheever 
  mine 
  near 
  Port 
  Henry. 
  In 
  1906 
  the 
  mills 
  

   at 
  Mineville, 
  Lyon 
  Mountain 
  and 
  Arnold 
  hill, 
  which 
  were 
  the 
  only 
  

   ones 
  operated, 
  crushed 
  729,091 
  long 
  tons 
  of 
  ore, 
  making 
  479,644 
  

   long 
  tons 
  of 
  concentrates. 
  

  

  The 
  system 
  of 
  magnetic 
  concentration 
  employed 
  is 
  practically 
  

   the 
  same 
  at 
  all 
  the 
  mines. 
  It 
  involves 
  dry 
  crushing, 
  sizing 
  and 
  

   treatment 
  of 
  the 
  product 
  by 
  magnetic 
  separators 
  of 
  which 
  the 
  

   Ball-Norton 
  drum 
  type 
  is 
  the 
  one 
  commonly 
  used. 
  1 
  The 
  crush- 
  

   ing 
  is 
  regulated 
  as 
  to 
  fineness 
  by 
  the 
  granularity 
  of 
  the 
  ores 
  which 
  

   varies 
  at 
  the 
  different 
  mines. 
  As 
  a 
  rule 
  it 
  is 
  not 
  carried 
  to 
  the 
  

   point 
  where 
  the 
  greatest 
  saving 
  of 
  the 
  magnetite 
  would 
  be 
  effected, 
  

   since 
  the 
  production 
  of 
  fine 
  concentrates 
  is 
  not 
  desirable 
  from 
  a 
  

   metallurgical 
  standpoint. 
  

  

  The 
  difficulty 
  in 
  handling 
  the 
  finer 
  grades 
  of 
  concentrates 
  in 
  the 
  

   blast 
  furnace 
  has 
  been 
  something 
  of 
  a 
  drawback 
  to 
  the 
  success 
  of 
  

   magnetic 
  concentration 
  as 
  applied 
  to 
  ores 
  in 
  which 
  the 
  magnetite 
  

   is 
  intimately 
  intergrown 
  with 
  the 
  gangue 
  minerals, 
  an 
  association 
  

   that 
  is 
  not 
  uncommon 
  in 
  the 
  Adirondacks. 
  Briquetting 
  has 
  not 
  

  

  1 
  For 
  further 
  details 
  of 
  the 
  apparatus 
  and 
  methods 
  used, 
  consult 
  the 
  issues 
  

   of 
  the 
  Engineering 
  and 
  Mining 
  Journal, 
  for 
  June 
  9, 
  and 
  November 
  17, 
  1906, 
  

   wherein 
  are 
  described 
  the 
  mills 
  at 
  Mineville 
  and 
  Lyon 
  Mountain. 
  

  

  