674 ANNUAL KEPOKT SMITHSONIAN INSTITUTION^ 1913. 



smelter at Kennett. This plant when running full has a capacity of 

 some 1,200 tons of ore per da3^ 



.The Balaklala, or First National Copper Co., Avas the most recent 

 of the Shasta County smelters, having blown in its first furnace in 

 1908. 



These smelters are all situated in the narrow precipitous canyon 

 of the upper Sacramento River and its tributary, the Pitt. The 

 region itself is too steep and rocky for agriculture, but was once 

 heavily Avooded, although now swept bare of vegetation for miles. 

 As far as the canyon itself is concerned, probably all the damage 

 possible has already been done unless reforestation were undertaken. 

 This latter even would probably be slow and difficult work, as since 

 (he loss of vegetation the steep hillsides have been washed bare of 

 soil for miles around. At Redding, however, some 13 miles below 

 Coram and 17 miles below Kennett, the canyon widens out into the 

 fei-tile Sacramento Valley and from this point southward for some 

 12 miles farther lies the region from which came increasingly in- 

 sistant complaints against the smelters. These culminated in the 

 spring of 1910 in agreements between the farmers and the smelters 

 under which friendly suits Avere brought in the Federal courts and 

 injunctions issued by stipulation requiring the smelters to remove 

 the susi^ended matter from their exit gases and dilute the latter to 

 such an extent that their sulphur dioxide content should not-exceed 

 seventy-five hundredths of 1 per cent by volume as discharged from 

 the stacks, Avith the further general and sAveeping provision that they 

 should do no damage. 



To accomplish this the Mammoth Smelter installed a bag house, 

 Avhich has been in very successful operation sinc^e July, 1910. Figure 

 19 is a AdeAv of this plant shoAving the bag house on the left in opera- 

 tion. It Avill be noted that the gases discharged from the five stacks 

 (each 21 feet square) are to all intents and purposes free from sus- 

 pended matter and consequently invisible. Thisq^-epresents a notable 

 achievement, being the first tune that the bag house, so efficient in 

 lead smelters, has been successfull}' applied to copper blast furnace 

 gases on the large scale. 



It is made possible in this instance through neutralization of the 

 sulphuric acid in the gases by the zinc oxide carried over in the fume 

 from the very heavj'^ zinc content of the ore smelted. The company 

 is also the oAvner of patents^ on the introduction of finely divided 

 metallic oxides into the gases for this purpose. In addition, it Avas 

 necessary to provide an extensive system of cooling pipes^ seen in 



1 Clarence B. Sprague, U. S. Pats. 931515, Aug. 17, 1909, and 984498, Feb. 14, 1911. 

 See also W. C. Ebaugh, Journ. Indus, and Eng. Chem., vol. 1, pp 686-6S9 (1909) and 

 vol. 2, pp. 372-373 (1910). Also "Notes on Bag-Filtration Plants," by A. Eilers. Trans. 

 Amer. Inst. Min-. Eng., vol. 44, pp. 708-735 (1912). 



