METALLURGY. (MISCELLANEOUS.) 



361 



The fluid open-hearth steel process in use in the 

 works at Pencoyd, Pa., is described by B. Talbot 

 as combining the rapidity of the Bessemer process 

 with the efficiency of the open-hearth process. As 

 carried on in the open-hearth furnace it consists 

 in working up a large bath (60 tons) and capping 

 off one third. To the remainder are added oxide 

 of iron and 20 tons of molten pig iron. The heat 

 of the bath causes these materials to react with 

 reduction of the oxide and oxidation of the im- 

 purities. A great heat is given out and is util- 

 ized in increasing the temperature of the bath. 

 When this metal is sufficiently refined the slag is 

 run out and one third of the steel is tapped out, 

 while the other two thirds are retained for mixing 

 with and purifying another 20 tons of pig iron. 



In the application of a similar process at Wish- 

 aw, as described by J. Riley, the charge is molten 

 metal from the blast furnace, with additions of 

 small quantities of pig iron for refining, but no 

 storage bath like that described in the Pencoyd 

 process is used. The results are satisfactory, and 

 involve a higher yield of steel with increased ore 

 reduction even over that when cold pig iron is 

 used, an increase of about 30 per cent, in the out- 

 put and a saving in the cost of labor at both blast 

 and open-hearth furnaces. 



A smokeless furnace invented by Mr. Pilatt, of 

 Nottingham, and represented as being applicable 

 to all types of boilers or wherever a furnace is 

 required, has as its basis a chilled iron bar, cast 

 hollow longitudinally with lateral openings cast 

 in the web of the bars. These lateral openings 

 or ports enable a regulated and sufficient supply 

 of warm air to be drawn directly from the ash pit 

 and delivered superheated at the back of the 

 bridge. The bridge is contrived so as to deflect 

 the superheated air, which instantly combines with 

 any combustible gas given off by the fuel and not 

 burned into a sheet of flame, and consumes all 

 smoke, at the same time bringing about an in- 

 creased temperature and a quicker generation of 

 team. In a " rocking attachment " to this fur- 

 e, by a simple movement of a lever the whole 

 te can be put in motion and clinkers broken 

 without opening the furnace and suffering an 

 mission of cold air. A forced draught furnace 

 vised by the same inventor, and noiseless, will 

 urn all kinds of fuel, while it is claimed it like- 

 ise works without smoke. 



A discovery by Mond that metallic nickel forms 

 volatile compound nickel-carbonyl with car- 

 bon monoxide has been utilized in a process de- 

 scribed by Roberts-Austen for the separation 

 of nickel from cobalt, copper, and other metals 

 with which it is associated in its ores. A similar 

 rocess is applicable to iron. 



In the new process of H. Goldschmidt for weld- 

 g the clean faces of the metal are brought into 

 ntact in the cold, and are then heated by pour- 

 g upon the joint the fused product of the reac- 

 ion of oxide of iron and aluminum contained in 

 special crucible. The joint is clamped so that 

 he local expansion in heating effects the weld, 

 clamps may be removed as soon as the weld 

 is complete. Sheet iron or iron gauze may be 

 inserted between the welding surfaces. 



A method of superheating the blast described 

 by F. Laret (Echo des Mines et de la Mtallurgie) 

 consists in interposing between the hot-air stoves 

 and the tui/f-rca an injector of heavy oils which 

 pass into the furnace, increasing the temperature 

 and the yield while greatly facilitating the reduc- 

 1 ion of the ore. It has been tried with satisfactory 

 results. Only smooth-faced iron is produced by 

 the arrangement, and the carbon and silicon con- 

 tents are considerably increased. 



A process of using dense liquids (saturated solu- 

 tions of certain salts) for the separation of coal 

 and shale is described by M. Maurice in the So- 

 ciete de 1'Industrie Minerale. The shale sinks and 

 the coal remains in the top of the solution. A 

 list of salts suitable for the process is given in the 

 paper, of which calcium chloride of 1.411 specific 

 gravity is the lightest and zinc bromide, 2.391 

 specific gravity, is the heaviest. 



An improved process for the production of po- 

 tassium and sodium by the reduction of those 

 metals from their salts consists in forming electro- 

 lytically an alloy of some heavy metal, such as 

 lead, with sodium or potassium, and then distilling 

 the latter. 



Miscellaneous. Mr. W. P. Rix, in a paper 

 read before the Society of Arts, expressed the 

 opinion that leadless glazes would ultimately be- 

 come available for use in nearly all kinds of 

 pottery. Hitherto little success had attended their 

 application to coarse earthenware owing to opalin- 

 ity, sluggish fusibility, and inequality of texture 

 Such glazes required to be dipped as thinly as 

 possible and with far greater uniformity than 

 was necessary in the case of the glazes generally 

 used. Until the leadless glazes were advanced to 

 the commercial stage, the problem which potters 

 were invited to solve was the reduction of the 

 amount of lead absolutely essential in the glazes 

 commonly employed. It should also be remem- 

 bered that the fritting of lead with silica, borax, 

 and stone could only produce innocuous results 

 when the proportions of earth were such that the 

 whole was chemically combined in a stable form. 

 So far there has been little opportunity to test 

 the leadless glazes, but Mr. Rix represents that 

 they have withstood severe exposure and rough 

 usage. 



In a lecture before the Royal Institution on the 

 structure of metals, Prof. J. A. Ewing showed, 

 from microscopical examination, that the structure 

 of polished metal is not homogeneous, but presents 

 numerous granules with irregular boundaries. 

 Each of these granules is a crystal essentially 

 composed of a multitude of exactly similar parts 

 all facing the same way. This crystalline struc- 

 ture accounted for the different luminosities pre- 

 sented by a given sample when viewed with light 

 falling at different angles, because the reflections 

 from the different faces were in different direc- 

 tions. Further evidence of the geometrical char- 

 acter of the structure is to be found in the geo- 

 metrically regular shapes of the pits formed by 

 minute particles of imprisoned air when cadmium, 

 for example, was cast against a perfectly smooth 

 surface, such as glass. 



The present use of blast-furnace slag in the 

 form of sand and as made into bricks and cement 

 was described in a paper on the subject by the 

 Ritter Cecil von Schwarz at the spring meeting 

 of the Iron and Steel Institute. Hitherto slag 

 cement appears to have been a somewhat untrust- 

 worthy article; but recently a process for the 

 manufacture of cement from blast-furnace slag has 

 been started in Germany and Belgium, the results 

 of which are regarded as highly satisfactory in 

 the points of strength, volumetrical constancy, and 

 reliability. In the manufacture of this cement 

 the slag is first granulated, and is then reduced 

 to sand. In this condition it is mixed with lime- 

 stone and slaked lime, and the mixture is reduced 

 to a fine powder. This powder is mixed with 

 water and made into bricks, which are air-dried 

 and afterward burned into clinker in a special 

 furnace. The clinker is stored for about six weeks, 

 and is then ground into a fine powder. The ce- 

 ment thus produced is said to be distinguished 



