2l6 LOWER PENINSULA. 



; COLLATERAL PRODUCTS OF MICHIGAN BRINES. 



As shown by the chemical analyses, Michigan brines contain, be- 

 sides salt, percentages of chloride of calcium, chloride of magne- 

 sium, and bromide of magnesium. 



Chloride of calcium, which forms the largest proportion of the 

 waste mother liquors, after the salt has been extracted from the 

 brine, is now having a value for various purposes. Its concentrated 

 solution is used as a bath in the putting up of canned fruit. It is 

 also employed in the manufacture of chloride of barium and arti- 

 ficial sulphate of baryta. 



In some localities, it has also found very extensive use in the 

 manufacture of artificial stones by the Ransom patent. The process 

 consists in mixing sand and silicate of soda by a pug mill into a mass 

 of putty-like consistency. In this condition, it is pressed into 

 moulds of any form and shape. After removing the'pattern or mould, 

 a strong solution of chloride of calcium is poured over the moulded 

 form, which so hardens the surface that it can be removed to a 

 tank containing a solution of chloride of calcium, in which it is 

 allowed to remain a certain length of time until the entire form 

 becomes perfectly hard. The decomposition which takes place in 

 the stone between the silicate of soda and the chloride of calcium 

 forming silicate of lime, which is the cementing material. The salt 

 produced is afterward washed out by repeated^oakings and wash- 

 ings in fresh water. 



Artificial stone made in this way has a fine texture, great dura- 

 bility, and when properly and carefully made equals in most 

 respects the best varieties of the native sandstone. 



Chloride of magnesium also contained in the mother liquors of 

 the salt works is a source for the manufacture of magnesia. A 

 caustic solution of lime precipitates the magnesia as a hydrate, 

 from which the calcined magnesia can be made by calcination. 

 Magnesia finds considerable use in the manufacture of rubber goods 

 and in pharmacy. 



Bromine contained in the brines, as a bromide of magnesium, is 

 now being extensively produced from the refuse bitter waters of 

 the salt manufacture. Bromine is largely used in the arts and 

 pharmacy. The annual American product of bromine is now over 

 130,000 pounds. 



The refuse salt obtained from the waste brines has a value as a 

 manure, and should find more general use. 



