249 - Ludwig HAARMANN

HAARMANN, a civil engineer of Hannover, had filed a German patent application in 1879 for a « Verfahren zum Herstellen basischer Ziegel aus Dolomit und Kalkmilch ». [1]

In the corresponding  British patent [2] the novel composition is defined as follows:

A thorough mixture, containing from 90 to 98 parts of raw,  unburnt, ground dolomite and from 10 to 2 parts of quicklime,  used however in the state of milk of lime, is formed into bricks, which are « kilned under a high temperature ». The lime then amalgamates with the small percentage of silica contained in the dolomite, producing « silicated lime », which binds the particles of the dolomite. 

On  22 September 1879 HAARMANN filed a corresponding patent application in Luxembourg under the title of:

Procédé de fabrication de briques réfractaires basiques par un emploi combiné de dolomie et de lait de chaux

The patent was granted under Patent Law of 1880. [3]


[1] DE patent application 25,631/1879

[2] GB patent No 10/1880, also FR patent No 132,466 and BE patent No 2,207/1879

[3] LU patent No 53