﻿Chemistry 
  and 
  Physics. 
  485 
  

  

  SCIENTIFIC 
  INTELLIGENCE. 
  

  

  I. 
  Chemistry 
  and 
  Physics. 
  

  

  1. 
  The 
  Extraction 
  of 
  Potash 
  from 
  Silicate 
  llocks. 
  — 
  William 
  

   H. 
  Ross 
  of 
  the- 
  U. 
  S. 
  Bureau 
  of 
  Soils 
  found 
  several 
  years 
  ago 
  

   that 
  when 
  1 
  part 
  of 
  feldspar 
  and 
  3 
  parts 
  of 
  calcium 
  carbonate 
  

   were 
  ignited 
  for 
  about 
  an 
  hour 
  at 
  a 
  temperature 
  of 
  1300-1400°, 
  

   the 
  potash 
  was 
  completely 
  volatilized 
  and 
  the 
  clinker 
  which 
  

   remained 
  had 
  a 
  composition 
  within 
  the 
  limits 
  required 
  for 
  Port- 
  

   land 
  cement. 
  He 
  observed 
  also 
  that 
  when 
  the 
  lime 
  was 
  partly 
  

   replaced 
  by 
  a 
  quantity 
  of 
  calcium 
  chloride 
  equivalent 
  to 
  the 
  alka- 
  

   lies 
  in 
  the 
  feldspar 
  the 
  volatilization 
  was 
  completed 
  in 
  about 
  one- 
  

   half 
  of 
  the 
  time. 
  From 
  these 
  results 
  it 
  was 
  concluded 
  that 
  

   potash 
  could 
  be 
  set 
  free 
  from 
  feldspar 
  by 
  substituting 
  it 
  for 
  clay 
  

   in 
  the 
  manufacture 
  of 
  cement, 
  and 
  that 
  it 
  might 
  be 
  collected 
  

   from 
  the 
  flue-dust. 
  Moreover, 
  since 
  the 
  ordinary 
  materials 
  used 
  

   for 
  cement 
  manufacture 
  contain 
  some 
  potash 
  it 
  was 
  expected 
  that 
  

   its 
  volatilization 
  would 
  take 
  place 
  in 
  the 
  usual 
  process. 
  This 
  has 
  

   been 
  found 
  to 
  be 
  the 
  case, 
  although 
  the 
  volatilization 
  has 
  been 
  

   found 
  to 
  be 
  only 
  partial 
  in 
  most 
  cases 
  on 
  account 
  of 
  the 
  short 
  

   time 
  to 
  which 
  the 
  clinker 
  is 
  exposed 
  to 
  the 
  proper 
  temperature, 
  

   but 
  in 
  several 
  plants 
  the 
  potash 
  is 
  now 
  being 
  collected 
  with 
  the 
  

   flue-dust 
  by 
  electrical 
  precipitation. 
  The 
  importance 
  of 
  this 
  

   matter 
  has 
  led 
  the 
  author 
  to 
  study 
  the 
  various 
  methods 
  that 
  have 
  

   been 
  proposed 
  for 
  the 
  extraction 
  of 
  potash 
  from 
  feldspar, 
  and 
  to 
  

   make 
  further 
  experiments. 
  The 
  patented 
  processes 
  relating 
  to 
  

   this 
  subject 
  now 
  exceed 
  100 
  in 
  number, 
  and 
  it 
  is 
  concluded 
  that 
  

   no 
  process 
  can 
  be 
  economically 
  successful 
  unless 
  there 
  is 
  recovered 
  

   at 
  the 
  same 
  time 
  some 
  other 
  product 
  of 
  value 
  in 
  addition 
  to 
  the 
  

   potash. 
  The 
  most 
  promising 
  use 
  of 
  the 
  by-product 
  is 
  for 
  cement, 
  

   since 
  a 
  vast 
  quantity 
  of 
  this 
  product 
  is 
  manufactured. 
  The 
  new 
  

   experiments 
  consisted 
  in 
  the 
  first 
  place 
  of 
  an 
  attempt 
  to 
  decom- 
  

   pose 
  feldspar 
  by 
  means 
  of 
  water 
  at 
  high 
  temperature 
  and 
  pres- 
  

   sure, 
  but 
  at 
  a 
  temperature 
  of 
  500° 
  C. 
  in 
  a 
  bomb 
  at 
  an 
  estimated 
  

   pressure 
  of 
  1,450 
  atmospheres 
  there 
  was 
  no 
  decomposition. 
  

   However, 
  when 
  the 
  powdered 
  feldspar 
  was 
  digested 
  with 
  water 
  

   and 
  1*7 
  parts 
  of 
  lime 
  at 
  a 
  steam 
  pressure 
  of 
  10-15 
  atmospheres 
  

   about 
  90 
  per 
  cent 
  of 
  the 
  potash 
  passed 
  into 
  solution 
  in 
  the 
  form 
  

   of 
  hydroxide 
  and 
  the 
  residue 
  had 
  the 
  composition 
  required 
  for 
  

   Portland 
  cement 
  clinker. 
  Since 
  the 
  pressure 
  here 
  required 
  can 
  

   be 
  safely 
  produced 
  in 
  an 
  ordinary 
  boiler, 
  the 
  process 
  is 
  regarded 
  

   as 
  a 
  promising 
  one. 
  — 
  Jour. 
  Indust. 
  and 
  Eng. 
  Chem., 
  ix, 
  467. 
  

  

  h. 
  l. 
  w. 
  

  

  2. 
  Preparation 
  of 
  Uranium 
  Dioxide. 
  — 
  Charles 
  L. 
  Parsons 
  

   of 
  the 
  U. 
  S. 
  Bureau 
  of 
  Mines 
  has 
  devised 
  a 
  simple 
  method 
  for 
  the 
  

   manufacture 
  of 
  the 
  black 
  oxide 
  of 
  uranium 
  from 
  the 
  sodium 
  

   uranate 
  obtained 
  from 
  carnotite 
  ore 
  at 
  the 
  Denver 
  plant 
  of 
  the 
  

   National 
  Radium 
  Institute. 
  When 
  uranium 
  is 
  extracted 
  from 
  its 
  

  

  