BUREAU OF SOILS. 303 



leacliinfT troughs and vacuum filters made up of wood, rubber, and 

 lead. The apparatus, although a makeshift, has worked splendidl}', 

 from the first has shown large capacity, and has been operated by one 

 man. A building has been constructed which now contains the entire 

 char-treating apparatus, measuring and extracting tanks, filtering 

 presses, and drier, with accessory equipment. The retort capacity for 

 activating carbon has been doubled by the erection of two furnaces 

 with four retorts. "With this equipment, however, the retort capacity 

 is still less than 50 per cent of the total quantity of char available for 

 activation. Difficulties involved in the operation of these retorts 

 have shown it advisable to devise some other method of activation. 

 After months of experimentation on the laboratory scale, an electric 

 furnace was designed and is now being installed, w-hich it is believed 

 will represent the solution of the problem of activating carbon on a 

 large scale. 



Carbon products produced in the laboratory furnace of this de- 

 sign showed an activity of about five times that of the products 

 handled by the retorts. Three grades of bleaching carbon, called 

 Kelpchar, grades Nos. 1, 2, and 3, have been produced. Grade No. 1 

 is that which was turned out in small quantities from the electric 

 furnace and which has an activity of some five times that of Norit. 

 Grade Xo. 2 is that which is now produced, approximating the 

 activity of Xorit, and accordingly being only one-fifth as active 

 as grade Xo. 1. Grade Xo. 3 is that which was prepared with the 

 use of sulphuric acid instead of hydrochloric, and being heavily 

 loaded with calcium sulphate, it is naturally less active, pound per 

 pound, than grade Xo. 2. 



The grade of material now obtained varies from 75 per cent to 

 100 per cent on the basis of Xorit, 100 per cent. Sales are being 

 made at 25 cents per pound. This grade of carbon has had a favor- 

 able reception, and we could have sold it in large quantities if we had 

 had it to sell. Samples sent out to various prospective users in many 

 cases elicited high praise and requests for opportunities to purchase. 

 We W'cre not able to meet the demand, however. The apparatus 

 installed has a capacity of 400 to 600 pounds active carbon a day, 

 depending entirely on the output of the activating retorts. This at 

 25 cents per pound represents a daily revenue of $100 to $150. The 

 successful operation of the electric-furnace installation should bring 

 this daily output promptly to 1,000 to 1,500 pounds per day. 



Laboratory researches carried on throughout the year on Kelpchar 

 have shown it to have a wide range of applicability, being a highly 

 efficacious bleaching agent for molasses, such as is used in the manu- 

 facture of yeast and vinegar; for malt sirups, the modern product of 

 reconstructed breweries and distilleries; dye intermediates of many 

 sorts; edible oils; crude lactic acid; and various other commodi- 

 tie.s. In some cases purification by bleaching carbon in a single oper- 

 ation has resulted in a better product than was formerly obtained 

 by rep'^ated and expensive crystallizations. This is especially tr\ie 

 of ce.tain dye intermediates, and it is confidently predicted that a 

 good grade of bleaching carbon of standard properties supplied to 

 the American chemical trade in substantial amounts at an equitable 

 price will play an important role in the development of American 

 chemical industries. 



