BRIQUETTING TESTS. 
41 
LABORATORY INVESTIGATIONS. 
In the laboratory investigations by Dr. J. E. Mills the substances named below were 
tested as binding materials in the manufacture of briquettes, both as to the possibility of 
their being used with the different varieties of bituminous coal and as to the percentage 
of each binder yielding the best results with each coal. The substances tested in this con- 
nection were as follows: 
INORGANIC HINDERS. 
Clay. 
Lime. 
Magnesia. 
Magnesia cement (magnesium oxide and magne- 
sium chloride). 
Plaster of Paris. 
Portland cement. 
Natural cement. 
Slag cement. 
Water glass. 
ORGANIC BINDERS. 
A. Wood products. 
Rosin. 
Pitch (rosin anrl tar). 
Pine-wood tar. 
Hard-wood tar. 
Beet pulp. 
Lime cake. 
Corn starch. 
Blast-furnace tar. 
Producer-gas tar. 
Illuminating-gas tar (from coal). 
Impsonite. 
Gilsonite. 
Maltha. 
Refined Trinidad. 
Douglas-fir tar. 
Wood pulp. 
Sulphite liquor (from paper mills.) 
B. Sugar-factory residues. 
I Beet-sugar molasses. 
I Cane-sugar molasses. 
C. Starch. 
| Potato starch. 
I). Slaughterhouse refuse. 
K. Tars and pitches from coal. 
By-product coke-oven tar. 
Coal-tar creosote. 
Various grades of pitches from various tars. 
Natural asphalts. 
Refined Bermuda. 
Hard and refined or gum (from impregnated 
sandstone, etc.). 
G. Petroleum products. 
Crude oil. 
Residuum (asphalts, etc.). 
Water-gas tar. 
Water-gas tar pitch. 
Wax tailings. 
Acid sludge. 
Asphalt tar. 
Pintsch-gas tar. 
Pittsburg flux. 
These investigations related not only to the nature and the amount of the binder neces- 
sary for making satisfactory briquettes with each of the several coals tested, but also to 
the extent to which the binding quality of certain of these materials might be improved 
by the admixture of another binding material or another variety of coal. 
Unless otherwise stated, 20 grams of each coal to be tested were weighed out and mixed 
with the different percentages of the binding material and placed in a Battersea crucible. 
A small amount of water was then added and the mixture heated with sufficient stirring 
to thoroughly mix the binder and coal until steam came off freely and only a small amount 
of water was left in the coal. The mixture while still hot was pressed in a small laboratory 
hand press, on which a pressure of 3,500 to 4,000 pounds per square inch was obtained. 
Each briquette weighed approximately 5 grams. 
