USEFUL MET\ 



color is often seen in door knobs. Intermediate amount* pro- 

 dint- the purple ami brown colors. The intensity of heat alo 

 effects the color. The oxide acts as n deeolori/.er in oni 

 glass, and therefore corrects the green color impart.-.! by iron. 



Manganese ores are used largely in the manufacture of chlorine 

 for the chlorination of gold. In the manufacture of bromine 

 where the ore acts as a carrier of oxygen. Manganese ores are 

 used in the manufacture of oxygen from potassium chlorate 

 where the black oxide of manganese plays the part of a catalytic 

 agent. Manganese ores are also used in the manufacture of 

 disinfectants. Here it serves as an oxidizing agent. They are 

 also used as a gas purifier in the place of IH>K iron. Manganese 

 ores are quite largely used in the disposal of municipal sewage, 

 for manganese ore becomes an important oxidizer with the appli- 

 cation of heat. 



They are also used in the manufacture of potassium permanga- 

 nate and the various salts of the metal for the chemical trade. 

 They are also used as a flux in silver-lead smelting, and in voltaic 

 batteries as a strong negative electrode. Manganese ores are 

 used as a drier in varnishes, as a coloring agent in calico printing, 

 in the manufacture of pottery, brick and many paints. 



Nine-tenths of all metallic manganese is used in the manufac- 

 ture of steel and in the alloys of the metal. In the manufacture 

 of steel two manganese alloys are employed. The one is spienel- 

 eisen, with less than 25 per cent, of manganese and with a 

 general average of 20 per cent, manganese. The other is ferro- 

 manganese, with more than 25 per cent, of manganese and a 

 general average of 80 per cent, manganese. The general ratio of 

 spiegeleisen to ferromanganese is 1:4. The effect produced 

 upon steel is intricate and very important. (1) It prevents the 

 formation of gas cavities during the solidification of the steel. 

 (2) It restores the necessary carbon to the steel. (3) It re- 

 moves oxygen from the iron in the steel and (4) it imparts great 

 hardness and toughness to the steel. A superior quality of 

 toughness is imparted by less than 3 per cent, of manganese. 

 With from 3 to 20 per cent of manganese the steel is particu- 

 larly well adapted for many purposes where great abrasion is 

 encountered, as in mine car wheels; in milling and crushing ma- 

 chinery; in coupling-pins; in car rails for curves, switches, freight 

 yards and wherever heavy traffic is common. 



One of the newest uses for manganese lies in the manufacture 



