82 president's address — section b. 



Eguilles converters had originally been built for steel-converting, were 

 of the customary upright, cylindrical type, with a hemispherical bowl 

 at the bottom and an equivalent dome at the top, surmounted by a 

 short neck or nose. They were 2m. high by l.'im. diameter, and had 

 a capacity of 3,000 kilos of pig iron when new, but which was equal to 

 only 1,500 to 2,000 kilos of matte. The bottom wind box was replaced 

 by an air belt encircling the body, and for the numerous bottom tuyeres 

 there were substituted 18 to 20 small horizontal tuyeres, placed about 

 0.3m. above the bottom of the cavity. The openings were about Ic.m. 

 in diameter, and at first were contained in special bricks 20c. m. long, 

 corresponding to the thick'ness of the lining. The latter was tlie same 

 everywhere, except at the nose. The lining was made up of clay and 

 sand, and lasted at first 10 to 12 operations — frequently only seven or 

 eight— while later on as many as 18 blows are said to have laeen made 

 blast pressure, 25c. m. to 35c. m. of mercury : and the air supply, 100 cub. 

 with one lining. The size of the charges was usually 1 ,000 kilos ; the 

 m. per minute. The ores at Eguilles weie, and still are, very impure, 

 and contain much arsenic, antimony, lead, and zinc, &c., all of which 

 elements, as already stated, it was at once observed, by the evidence 

 of the rolling mill, were as completely removed, either by scorification 

 or volatilization, as if the mattes had been derived from clean ores. 

 The cost of the operation stood at from 160 to 170 francs per ton of 

 copper — a figure which compared exceedingly favorably with the cost 

 of the analogous operations in the Welsh process. This, notwith- 

 standing that fuel in England was only half as dear as in Southern 

 France, amounted to from 320 to 350 francs. The rather high copper 

 contents of the converter slags (2 per cent, to 3 per cent.) were recog- 

 nised as an indifferent matter, since the slags could be returned to the 

 matting furnaces. By contrast with the Chili bars which were refined 

 in the same locality, and which contained at least 4 per cent, of im- 

 purities, the production of a black copper by the converter, with only 

 1.5 per cent, foreign elements, caused considerable eclat. In addition 

 to the lightening of the refining operation from this source, the simplifica- 

 tion of the entire course of treatment by reducing the former six to 

 eight operations, from ore to copper, down to only three — i.e., smelting 

 for matte, converting and refining — together with the concomitant 

 saving in fuel and labor, and the extraordinary gain in expedition, 

 were all points which were enthusiastically appreciated. 



These metallurgical achievements formed one of the last subjects 

 which Professor Gruner— who, in the early days of the Bessemer steel 

 process, had been none too favorably impressed with its possibilities — - 

 interested himself in. A posthumous essay of his (1883) on the 

 subject (o) was completed by his son, and forms the first authoritative 

 statement published after the no less meritorious, but now forgotten, 

 Russian announcement of a dozen years before. The method since 

 this time goes under the name of the " Manhes process." Grunor's ap- 

 preciation is expressed in his final remarks : " I will not contend that 

 the Bessemerising process will alter the metallurgy of copper as radically 



(o) Annales des Mines, 8 e Serie, Tome III., p. 429. 



