Bisbee daily review., 1918-09-01


 There is probably no great difference | between the total heat loss in the two methods. It will be interesting, when sufficient definite figures from a num- Der of plants become available for the purpose, to work out the balance of cost between the two systems, taking into account the smelling capacity per campaign, giving proper credit for | the larger heat recovery per unit of | copper produced by side charging. At the Calumet & Arizona the charge | going to the reverberatOries is cold, consisting of silicious ores. As the l reverberatories are new operated al this plant high sulphur ore is used as cleaner preparatory to skimming. It | has been proposed by some metallurg- | ists to employ super-heating at the | slag end of the furnace before skim ming, for which purpose auxiliary burners on the side would be requisite
 At the time of my visit each of the | furnaces in the plant was treating | 400 tons per day, exclusive of con- verter slag, but recent charges have | increased this to zoo tons. At Fl Paso also the smelling capacity was great | ly augmented with altering the struc- tural details of the furnace This in- crease in smelting capacity is the re- suit of a more perfect combustion of the fuel oil close to the firing end, which in turn limits the smelling zone to approximately the same limits. The charging accordingly is not carried so | far toward the front of the furnace. | leaving the remainder of the hearth to constitute a pool in which the matte separates more perfectly from the slag. The distribution of heat under this system is satisfactory as under the old system where a longer flamI was used, and the more perfect com bustion results in securing the requis- ite heat with a reduced quantity of fuel. The advantage is conspicuous when firing is done with oil. but it appears to be even greater when pow dered coal is employed.
 The converter slag returned to the reverberatories, at the Calumet & Ari- zona plant. averages about 500 tons per day; it is poured into the furnaces in a molten condition and assays about 3.25 per cent copper.
 The copper in the reverberator charge is from 5:16 to $40 per cent.
 The official statement of the com pany gives the consumption of fuel oil per ton of total charge as 0.752 bbl Steam recovered from the waste-heat runs a credit to the reverberatory of 0.29S bbl. per ton of charge, leaving 454 chargeable exclusively to smelting These figures have been reduced to an average of 0.719 bbl. of oil burned per ton of total charge; a steam-credit of 0.S03, and a net consumption, charge able against the ore smelted, of 0.416 bbl. A Californian asphalt-base oil. of 2S degrees Baume, having heating value of 19,000 B. t. H., is used. The elimination of sulphur from the charge by vOlatilization during smelt- ing is about 27 per cent of the total in the ore fed. The reverberatories and the blast-furnaces are at the op- pOsite ends of the same structure, and are parallel to the converter building, so that the matte from both is deliver ed into ladies within the adjacent con veTter plant, and within reach of the cranes.
  mounting 12 feet basic lined convert CTS of the Great Falls type. Two eX- tra shells are kept on hand'to facili- tate repairs. The silica is fed into the converters through pipes leading from overhead bins. The matte is blown to blister containing on an aver age 9915 per cent copper. It is cast into ingots of 300 lb. each, being poured from 160 GU. fet. cast steel lad les into molds in a straight line cast ing machine The ingots are shipped to the Nichols Copper company at Laurel Hill, New York. The conver- ter-scrap is handled back to the con verters, with the exception of the skulls. These are broken in a Me GregOr skull-breaEer, and are then sent to the blast furnace beds. The amount of broken skulls is about 150 tons per day, and assays 10 per cent copper.
 The roaster stack is separated from all others. It is 20 feet in diamater and 279 feet high. The dust recovered in the roaster dust-chamber amounts to 22 tons daily and contains about 5.6 per cent copper, 0.3 per cent lead, 3.3 per cent zine, ounces silver and 0.06 ounces gold per ton. From the dust chamber in the flow line of the acid plant two tons per day of sim liar product are collected The con verter gases, amounting to 240, 0,000 cubic feet per minute show moder ate stack loss in dust containing ap- prcximately IS per cent copper 34 per cent lead, 9.5 per cent zinc with Ills oz. silver and O.OS6 oz. gold per ton. it is probable that a Cottrell treateI will be installed to recover this dust. The general superintendent of the Cal umet & Arizona shelter is H. A. Clark. and the metallurgist in charge of smelling operations is Carl H. Cole.