METALS. 



541 



nace smoke the sulphurous gases, and securing 

 economically their conversion into sulphuric 

 acid. 



Messrs. Vivian and Sons, the eminent cop- 

 per-smelters of Swansea, have of late years 

 been making earnest attempts toward the 

 utilization of the sulphurous gases of the smoke 

 from their works. To this end they have, 

 during the year 1865, examined the new fur- 

 nace invented by M. Gerstenhofer, a German 

 chemist, and have purchased his patent for the 

 sum of 4,000. Near the close of the year 

 Mr. Thomas Bell brought forward another in- 

 vention for the purpose, which excited some 

 interest ; and the same firm has invited him to 

 test the practical working of his method. Mr. 

 Peter Spence, who is at the head of the Pen- 

 dleton Alum "Works, probably the largest of 

 the kind in the world, has meanwhile had in 

 operation during three years past a form of 

 copper-ore calcining furnace, devised by him 

 with a view to the utilization of the copper 

 r-moke, and for which he claims, over M. Ger- 

 stenhofer's, the merit at least that it does not 

 necessitate a previous pulverizing of the ores. 



The value of the sulphur wasted in the cop- 

 per smoke at Swansea alone has been estimated 

 at 250,000 per annum. But Mr. Spence, 

 taking the amount of ores there worked at 

 about 5,000 tons weekly, and the proportion of 

 sulphur in them as averaging 24 to 28 per 

 cent., finds this equivalent to 3,300 tons weekly 

 of brown oil of vitrol, and to a yearly value, 

 at present prices, of more than 500,000. The 

 quantity of acid named would go far toward 

 meeting the requirements of the staple com- 

 mercial manufactures of the country, and at a 

 time when so many parts of the world are be- 

 ing ransacked for ores of sulphur. It is now 

 confidently expected that, by means of Spence's 

 or of some other form of smoke-collecting fur- 

 nace, the sulphur hitherto worse than wasted 

 at the copper works, will hereafter be made to 

 yield to the smelters instead a handsome return 

 in profits. 



Spence's Copper-Ore Calcining Furnace. 

 This furnace is of about fifty feet length from 

 end to end, consisting of two chambers one 

 above the other, separated by a thin partition 

 of fire-brick, and between which no communi- 

 cation exists. The lower chamber, having the 

 fire-place at one end, and opening at the other 

 into the chimney, alone contains and discharges 

 the products of combustion. In each side of 

 the upper or ore-chamber are six apertures, 

 respectively about eight feet apart, through 

 which the workmen can, at the proper inter- 

 vals, move the ores forward from the less to 

 the more highly heated end of the chamber, 

 these apertures being ordinarily closed^ with 

 doors. An opening at one end of this chamber 

 also admits continually, while the furnace is in 

 action, a current of air ; and this, taking up in its 

 course, the sulphurous and other gases disen- 

 gaged during calcining by the ores, escapes 

 loaded with these at the opposite end into 



Bulphuric-acid chambers. Fresh batches of ore, 

 about 1,000 Ibs. weight, are introduced every 

 two hours at the end of the ore-chamber 

 farthest from the fire-place (and so the less 

 heated), and are evenly spread out on its floor ; 

 and, after the first one or more charges have 

 been put in, these are, of course, just previously 

 raked forward eight feet each, to make room 

 for the new one ; the doors are then closed, and 

 the whole is left undisturbed until the time 

 again for a new charge. The first batch put in 

 is withdrawn at the end of twelve hours ; and 

 thereafter one is withdrawn and one intro- 

 duced at the end of every two hours. The ac- 

 tion of the furnace is thus unintennitting, and 

 it calcines about six tons of ore in each twenty- 

 four hours. The ores being exposed in their 

 transit to a gradually increasing temperature, 

 clotting is entirely prevented ; and their sulphur, 

 combining with oxygen, forms sulphurous acid, 

 to be subsequently converted into sulphuric 

 in the proper chambers and in the usual way. 



Mr. Spence states the cost of calcining by his 

 furnace at only 2s. \\<L. per statute ton of ore, 

 which is less than the cost of calcining by the 

 furnaces generally in use; while, further, for 

 every five tons of ore calcined, 9 worth of oil 

 of vitriol is obtained, at a cost of not more than 

 1, and from constituents which the ordinary 

 furnaces turn to no account. For the three 

 years during which this furnace has been in 

 use, all the sulphuric acid used at Mr. Spence's 

 works, whether at Pendleton or at Goole, have 

 been produced through its agency. MecJi. 

 Magazine, October 13, 1865. 



Qerstenhofer'i Copper Furnace. This con- 

 sists of a rectangular vertical chamber, con- 

 structed of fire-brick, and having within it, from 

 above downward, a succession of flat horizontal 

 bars or bearers of the same material, and so ar- 

 ranged that those in any one series do not stand 

 directly over those of the next. The ore, pre- 

 viously finely divided, is admitted in regulated 

 supply between feed-rollers, situated within the 

 roof of the furnace and a little above the upper- 

 most row of bars ; and first piling up on these, 

 it gradually flows over and descends upon those 

 below, until, by the time it escapes at the bot- 

 tom of the furnace, it is supposed to have part- 

 ed with all its sulphur. Below all the bars is 

 an open space in which a grate of ignited wood 

 or charcoal is kept well supplied till the charge 

 in the furnace is thoroughly fired, but is then 

 withdrawn the sulphur of the ore afterwards 

 keeping up the combustion. Just above the 

 upper bars are channels in the sides of the fur- 

 nace, through which escapes the air of the blast 

 or draught continually thrown in from below 

 and bearing with it the products of combus- 

 tion, first, into a chamber in which it deposits 

 the dust from the ores and also arsenious acid, 

 and then into the usual sulphuric-acid cham- 

 bers The regulated current of air mechani- 

 cally thrown in to form the draught, is previ- 

 ously conducted in pipes about the exit channels, 

 and economizes much of the heat of the escap- 



