KETTLE PROCESS 55 



loss of fuel, as gypsum or plaster of Paris is one of the 

 poorest conductors of heat. The workman therefore draws 

 the salt from the kettle, removes the remaining salt brine, 

 called pickle, to within a few gallons and refills the kettle 

 with fresh water. After a continuous boiling- of about half 

 an hour the greater part of the adhering salt has dissolved 

 and the rest of the incrustation can be readily removed. 



The kettles properly cleaned are washed with fresh brine, 

 refilled with the same and the boiling, panning and draw- 

 ing of the kettles continues till the incrustations have accu- 

 mulated not only in the kettles nearest the source of heat 

 but also in those farther away towards the chimney. Now 

 the fires are allowed to go out and at the same time the ac- 

 cumulated salt is removed from all the kettles. The old 

 pickle or the mother liquor as it is also called, is dipped out 

 as far as practicable into the gutter and the kettles are 

 then refilled with fresh brine from which in the front kettles 

 a considerable quantity of salt crystallizes, due to a partial 

 evaporation of the brine by the heat retained in the arches. 

 This salt is called " cool down salt ; " it is much coarser than 

 the boiled salt and usually kept separate. The time a salt 

 block is in operation is between 10 to 15 days, a " 10 or 15 

 days run." The manufactured salt having been all de- 

 posited in the bins, it is " leveled off " and according to the 

 state law remains undisturbed for 14 days for drainage, 

 when it is ready for the market. A salt block usually cools 

 sufficiently in 12 hours, when the kettles, grates, arches, 

 etc., are properly cleaned and made ready for the next 

 " run." The time required for this is 24 hours, so that 

 about two runs can be made in one month. The quantity 

 of salt produced in 24 hours in a good salt block with 

 average good coal dust and brine on the "Onondaga Salt 

 Reservation " is from 500 to 600 bushels of 56 pounds each 

 and the amount obtainable by the burning of one ton of 

 2000 pounds of this fuel varies from 45 to 50 bushels. 

 These results depend mainly on the quality of the brine em- 



