From: null@void.com   
      
   "Jim Wilkins"  writes:   
      
   > "Richard Smith"  wrote in message news:m1h5yyabun.fsf@void.com...   
   >   
   >> ... then weigh and plot the mass-fraction ...   
   >   
   > How do you weigh it?   
   >   
   > I ask because accurate weighing is among the more involved and   
   > error-prone operations in chemistry.   
   >   
   > https://chem.libretexts.org/Ancillary_Materials/Demos_Techniqu   
   s_and_Experiments/General_Lab_Techniques/Proper_Use_of_Balances   
   >   
   > A general principle of measurement is try to be 10 times as accurate   
   > as you require. With luck and practice the accumulating errors will   
   > still leave you what you need, in your case the possible value of lost   
   > gold versus the cost to recover it.   
      
   Kitchen scale from a "box store" - GBPounds6 - so about US$7or8.   
   1gram resolution on readout.  Range 0 to 6kg.   
      
   I am currently test-grinding granite chippings, of no value &   
   builder's merchant cost.  Finding out what happens.  It's a "broadly"   
   exercise.   
   Most mass-fractions are in the hundreds and into 4-figures of   
   grams, so for now that's good enough.   
   So I am pleased with the results so far.   
   I got two large plastic kitchen bowls at the "box store", and quite a   
   number of stainless steels bowls of various sizes from a shop in an   
   ethnic area my friend passed through in London.   
   I am "just" pleased I have anything at the moment.   
      
   One result so far   
   http://weldsmith.co.uk/tech/minerals/250709_sa_rm10gran/250709_sa_rm10gran.html   
   "Particle Size Analysis on rod-mill "mis-grind" of 10mm granite chippings"   
      
   Another nearly done having updated mill.   
      
   Will look to improve weighing equipment if have jobs which matter.   
   Suggestion is resolve to 0.1g   
      
   Regards,   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)