摘要:
In a process for the removal of mercury by treatment with elementary nickel an external voltage is applied to maintain the potential of the nickel at a value which differs from the potential of the reversible hydrogen electrode in the liquid concerned by not more than from -250 mV to +50 mV. The treatment is carried out at temperatures of from 80.degree. to 230.degree. C.
摘要:
Aqueous solutions of hydroxylamine are prepared from aqueous hydroxylammonium salt solutions by electrodialysis by a method in which the aqueous hydroxylammonium salt solution is fed into the middle zone of an electrolysis cell, which is divided into a cathode zone, an anode zone and a middle zone by means of semipermeable membranes, and is electrolyzed, and the catholyte used is an alkali metal hydroxide solution containing ammonia and/or amines.
摘要:
An electrode for electrolysis purposes, which may in particular be used as an anode for the electrolysis of alkali metal chlorides, contains, in addition to an alloy of niobium with a metal of the iron group, tantalum, tantalum carbide or an alloy of tantalum with metals of the iron group, individually or as mixtures. The surface of the electrode is modified with a metal of the platinum group, especially with rhodium.
摘要:
Metal-free phthalocyanines (PC) are prepared by electrolysis, at inert electrodes, of aromatic o-dinitriles in organic liquids which contain small amounts of dissolved electrolytically conductive compounds, in the presence of hydrogen or of a compound which eliminates hydrogen under the reaction conditions and in the presence of alkaline compounds (as activators). The PC formed may be isolated in the pure form by filtration. The product contains from 90 to 99% of PC. It is used for the preparation of PC-based pigments.
摘要:
Aqueous solutions of hydroxylammonium carbonate are prepared from aqueous hydroxylammonium salt solutions by electrodialysis by a method in which the aqueous hydroxylammonium salt solution is fed into the middle zone of an electrolysis cell, which is divided into a cathode zone, an anode zone and a middle zone by means of semipermeable membranes, and is electrolyzed, and the catholyte used is an aqueous solution of an ammonium carbonate or an alkali metal carbonate or of one of the corresponding bicarbonates.
摘要:
Blue iron hexacyanoferrate-III pigments are produced by a process wherein complex iron-II hexacyanoferrate-II (Berlin white) is prepared by electrolysis of an aqueous catholyte solution containing (a) an iron-II salt, (b) an alkali metal salt, an ammonium salt or a mixture of these, and (c) hydrogen cyanide, in an electrolysis cell in which the anode chamber and cathode chamber are separated by an ion exchange membrane, using an electrically conductive aqueous liquid in the anode chamber, and the iron-II hexacyanoferrate-II obtained is then converted to the blue pigment.The process gives Berlin white, which is substantially free from salt, in high yield and high purity. Pollution caused by the process is very low, since only a small amount of salt is produced. Compared with the corresponding blue pigments produced by prior art processes, the pigments obtained give purer colorations with better gloss, and are of higher color strength.
摘要:
A delivery drum includes at least one supporting shell for supporting a printed sheet and for producing a vacuum region between the supporting shell and the printed sheet. The supporting shell extends over the entire width of the printed sheet. A circumferential length, which is at least one quarter of the sheet length of the printed sheet, is disposed between the sheet start of the printed sheet and the start of the vacuum region.
摘要:
A method of varying a drum profile of a vario drum for transporting printing material sheets, in which shell segments of the vario drum are pivoted inward and outward. Sheet supporting elements assigned to the shell segments are reversibly deformed by pivoting the shell segments. A vario drum suitable for implementing the method and a machine containing the vario drum for processing printing material sheets contain the shell segments and the associated sheet supporting elements.
摘要:
Device for contactless guidance of sheetlike material being dragged along a travel path, the device having a guide surface member extending spaced from the travel path and being provided with air-blowing nozzles, includes a guide zone formed in the guide surface member wherein the air-blowing nozzles are disposed in a manner that a common flow pattern or gap flow formed during guidance of the sheetlike material is determined essentially by a first velocity component in a direction of motion of the material along the travel path and by a second and a third velocity component directed towards two side edges, respectively, of the travel path, the second velocity component being associated with one of the side edges and the third velocity component being associated with the other of the side edge.
摘要:
A delivery drum includes at least one supporting shell for supporting a printed sheet and for producing a vacuum region between the supporting shell and the printed sheet. The supporting shell extends over the entire width of the printed sheet. A circumferential length, which is at least one quarter of the sheet length of the printed sheet, is disposed between the sheet start of the printed sheet and the start of the vacuum region.