- Email: [email protected]
Zinc by electrolysis
440
Nares aJzd CammeJtts.
[J. F, l.,
from rusting. The trouble arises partly frmn the g~adual cracking of t h e paint film which allows the penetration of moisture and corrosive gases" t o the metal surface, causing the formation of rust aud the lessening of t h e adherence of the paint, and partly to chemical changes in the paint film i t s e l f by the absorption of sulphurous gases. F r o m these causes principally t h e frequent renewal of paint on exposed iron structures is found to be a necessity to preserve their integrity, and the nonfinal cost of this sort of work to t h e railroad companies is a very considerable item. Numerous investigations have been undertaken with the view of finding some substitute for the p a i n t s and oils usually employed for the pnrpose, or to secure their better a d h e r e n c e and greater durability, but thus far without substantial results. The overhead iron work of one of the stations of the Manhattan Elevated Railroad in New York affords a conspicuous example of what has been stated. It was found that the metal of this structure is so strongly and rapidly corroded by the sulphurous gases of the locomotives that the yearly renewal of t h e paint with which it was coated was iusufficient to preserve it. It was accordingly determined to make an exhaustive series of trials of the most approved paint compositions that could be found in t h e nmrket. Some eighteen different compositions were applied to different portions of the structure, and t h e i r effects as protective coverings are to be closely observed. The specially interesting feature of these trials, however, is the fact t h a t the sand-blast was used for the purpose of removing the old paint and t h o r oughly scouring the metal before applying the new coatings. The object o f this prelinfinary treatment was to obtain a clean metallic surface, to which t h e paint would adhere as perfectly as possible. The result of this operation h a s thus far not been made public. W. PIVOTED OR S W I N G I N G WINDOWS. The city of Chicago has enacted a building ordinance requiring t h a t on all new buildings there shall be swinging windows above the second story. The object sought to be accomplished by this enactment is to prevent t h e accidents in washing windows which are of common occurrence. The ordinance specifies that the window must swing on four vertical o r horizoutal pivots, or otherwise a balcony must be built around every window. It is said that the local architects and builders object to the law. W. ZINC BY ELECTROLYSIS.
gleclrica.1 Reviezo is responsible for the statement that the extraction o f zinc from its ores by electrolytic methods has been attempted at t{ayle, i n Cornwall, and at Milton, in Staffordshire. At the first-named place a leaching process, patented by Cowper-Co:es, was operated with indifferent results, and the experimental plant is now shut down. At Milton the SwinburneAshcroft fusion process has been under trial by the Phoenix Process S y n d i c a t e with fairly satisfactory results. The inventors believe that with slight modifications this process will solve the problem of winning all the metals contained in t h e mixed sulphide ores. The experimental trials o f this process have been transferred to Weston Point, and the Milton works have now been dismantled. W.
Nares aJzd CammeJtts.
[J. F, l.,
from rusting. The trouble arises partly frmn the g~adual cracking of t h e paint film which allows the penetration of moisture and corrosive gases" t o the metal surface, causing the formation of rust aud the lessening of t h e adherence of the paint, and partly to chemical changes in the paint film i t s e l f by the absorption of sulphurous gases. F r o m these causes principally t h e frequent renewal of paint on exposed iron structures is found to be a necessity to preserve their integrity, and the nonfinal cost of this sort of work to t h e railroad companies is a very considerable item. Numerous investigations have been undertaken with the view of finding some substitute for the p a i n t s and oils usually employed for the pnrpose, or to secure their better a d h e r e n c e and greater durability, but thus far without substantial results. The overhead iron work of one of the stations of the Manhattan Elevated Railroad in New York affords a conspicuous example of what has been stated. It was found that the metal of this structure is so strongly and rapidly corroded by the sulphurous gases of the locomotives that the yearly renewal of t h e paint with which it was coated was iusufficient to preserve it. It was accordingly determined to make an exhaustive series of trials of the most approved paint compositions that could be found in t h e nmrket. Some eighteen different compositions were applied to different portions of the structure, and t h e i r effects as protective coverings are to be closely observed. The specially interesting feature of these trials, however, is the fact t h a t the sand-blast was used for the purpose of removing the old paint and t h o r oughly scouring the metal before applying the new coatings. The object o f this prelinfinary treatment was to obtain a clean metallic surface, to which t h e paint would adhere as perfectly as possible. The result of this operation h a s thus far not been made public. W. PIVOTED OR S W I N G I N G WINDOWS. The city of Chicago has enacted a building ordinance requiring t h a t on all new buildings there shall be swinging windows above the second story. The object sought to be accomplished by this enactment is to prevent t h e accidents in washing windows which are of common occurrence. The ordinance specifies that the window must swing on four vertical o r horizoutal pivots, or otherwise a balcony must be built around every window. It is said that the local architects and builders object to the law. W. ZINC BY ELECTROLYSIS.
gleclrica.1 Reviezo is responsible for the statement that the extraction o f zinc from its ores by electrolytic methods has been attempted at t{ayle, i n Cornwall, and at Milton, in Staffordshire. At the first-named place a leaching process, patented by Cowper-Co:es, was operated with indifferent results, and the experimental plant is now shut down. At Milton the SwinburneAshcroft fusion process has been under trial by the Phoenix Process S y n d i c a t e with fairly satisfactory results. The inventors believe that with slight modifications this process will solve the problem of winning all the metals contained in t h e mixed sulphide ores. The experimental trials o f this process have been transferred to Weston Point, and the Milton works have now been dismantled. W.