Disclosed is an apparatus for conversion of ammonia into oxides of nitrogen which may comprise an adiabatic burner (108), a set of platinum/rhodium alloy catalytic gauzes (102A), (102B), and (102C), a waste heat recovery boiler (WHRB) (110), an absorption tower (302A), (302B), (302C), (302D) and (302E), a NaOH tank (306) and a surge tank (304). Further, the adiabatic burner may be configured to carry out catalytic oxidation of air and ammonia, using catalytic gauzes (102A), (102B), and (102C) of platinum/rhodium alloy. Further, the mixture of air and ammonia may be selectively oxidized to oxides of nitrogen, which may be absorbed in an alkali medium in the absorption tower (302A), (302B), (302C), (302D) and (302E), to yield sodium nitrites and nitrates.

The invention relates to a method for producing noble metal nets on flatbed knitting machines, the steps involvingproviding noble metal wire comprising platinumproviding yarn that is combustible or soluble in solventknitting two-bed items by simultaneous knitting on the front and rear needle beds and joining the two knitted fabrics by means of connecting pile threads, wherein, on the front or on the rear needle bed, a combustible or soluble yarn is used which is burnt off or dissolved after the knitting process, and a noble metal wire is used on the other needle bed and for the pile threads such that, after the combustible or soluble yarn has been burnt off or dissolved, there remain only the pile threads and the knitted fabric made of noble metal wire and produced on the rear or front needle bed.

A recovery system for recovering volatile precious metals from a gas phase, particularly for selectively recovering Pt and/or Pd, but not Rh from a gas phase. The recovery system is characterized in that it includes a plurality of woven or knitted metallic silver gauzes stacked on top of each other, or a plurality of layers of a ceramic or glass support coated with metallic silver, or a combination of both. The disclosure further relates to a method for recovering volatile precious metals from a gas phase, a system for the catalytic conversion of ammonia into nitric oxide including a recovery system according to the recovery system of the disclosure, and the use of the system for the catalytic conversion of ammonia into nitric acid, and for the catalytic ammonia into nitric oxide

The invention relates to a precious metal mesh which is knitted on a flat-bed knitting machine, having at least two float stitches per wale, thus having a significantly higher density for a given latch needle density of the flat-bed knitting machine than the precious metal mesh according to the prior art.