﻿DEY SUBSTITUTES FOE LIQUID LIME-SULPHUE 



21 



DRY BARIUM-SULPHUR COMPOUNDS 



The dry barium-sulphur compounds, which are sold as substitutes 

 for lime-sulphur solution, are of comparatively recent origin. Several 

 methods for their preparation have been developed, and patents ^^ 

 granted covering some of these processes, but all, or practically all, 

 of those produced at the present time consist simply of a mixture 

 of "black ash" (a crude barium-sulphide, BaS, made by heating 

 barium sulphate with coal in a furnace) and sulphur. 



CHEMICAL COMPOSITION 



Commercial dry barium-sulphur contains — in addition to barium 

 sulphide and sulphur — chemically combined water, some barium sul- 

 phate, sihceous material, carbon, and small quantities of other impuri- 

 ties. These impurities are objectionable in that they decrease the 

 percentage of active ingredients, impede their action, tend to clog the 

 nozzle 01 the spraying apparatus, and the graphitelike residue 

 from the coal is very destructive, on account of its abrasive action, 

 to the spray pumps and nozzles. 



The results of analyses of nine samples of commercial dry barium- 

 sulphurs purchased in various parts of the United States are given 

 in Table 18. 



Table 18. — Chemical composition of representative dry barium-sulphurs 



Sample 

 No. 



Barium- 

 sulphide 

 (BaS) 



Free 

 sulphur 



Barium- 



thiosul- 



phate 



(BaSjOs) 



Other 

 ingredi- 

 ents, by 

 difference ' 



Sample 

 No. 



Barium- 

 sulphide 

 (BaS) 



Free 

 sulphur 



Barium- 



thiosul- 



phate 



(BaSsOa) 



Other in- 

 gredients, 

 by differ- 

 ence! 



1 



Per cent 

 34.81 

 32.84 

 35.30 



Per cent 

 38.64 

 36.24 

 32. 03 



PcT cent 

 3.46 

 4.32 

 4.55 

 1.98 

 7.47 



Per cent 

 23.09 

 26.60 

 28.12 

 14.25 

 20.26 



6 



Per cent 

 38.00 

 39.76 

 39.41 

 38.10 

 38.46 



Per cent 

 34.01 

 34.88 

 33.66 

 34.60 

 34.69 



Per cent 

 3.97 



Per cent 



24.02 



2 



7 



2.96 22.40 



3 



8 



1. 28 25. 65 



4 



46. 66 37. 11 

 41. 22 31. 05 



9 



4.09 

 3.79 



23.21 



S 



Qen. av 



23.07 











' Chiefly barium sulphate, siliceous material, carbon, and moisture. 



The dry barium-sulphurs, when diluted according to directions (12 

 to 14 pounds to 50 gallons of water), leave an insoluble residue 

 which on filtering and drying at 105° C. amounts to about 34 per 

 cent of the product. The soluble portion has a specific gravity of 

 about 1.014 and contains approximately 2 per cent of barium-poly- 

 sulphide in solution. The ratio of sulphur to barium indicates that 

 the polysulphide is largely the tetrasulphide (BaSi) . This will furnish 

 approximately 8.5 pounds of barium-polysulphide in each 50 gallons of 

 spray material. 



Commercial liquid lime-sulphur (32° B.) at a dilution of 6.66 gallons 

 to 50 gallons of water (1 to 7.5), which was the strength used in the 

 tests here reported, will furnish approximately 22.8 pounds of cal- 

 cium-polysulphides in each 50 gallons of spray material. 



The experiments with dry barium-sulphur were a pnrt of the series 

 of tests with the various dry substitutes for liquid lime-sulphur. 

 These tests were made under the same general conditions as those 

 already described. 



» United 8tat«e Nos, 1,2«3,86« and 1,467.682. 



