Filter cakes are elutriated and drained mineral slurries, which have a homogeneous structure and only contain grain fractions smaller than 0.4 mm. Thus they are free from irritating coarse components such as wood, pyrite, calcite or quartz aggregates. The residual humidity varies between 15 to 35 % by weight depending on the type/quantity of the containing clay minerals.
In the brickworks, filter cakes do not have to be crushed with high energy expenditure, but only mixed homogeneously with the other mass components. In general the drying and firing process flow smoothly. In principle, low amounts of organic carbon are advantageous. Similar to natural clays the sintering activity and the fired color depend on the type/quantity of clay minerals as well as coloring oxides.
Almost all filter cakes of pit and quarry industry result from the mineral washing of solid rocks. With distinct focuses in paleozoic especially devonian times, filter cakes are obtained from rocks of a huge stratigraphic period from Early Devonian to Neogene.
In the brick and tile industry, clay mineral filter cakes are used as a substitute for loams, marls and slightly to medium plastic clays. They are clay substitutes with modified technical properties. In some cases, specific quality characteristics of natural clays are even exceeded.
In the German aggregate industry, there are around 20 locations/plants with installed chamber/membrane filter presses. Further press locations are planned nationwide. The individual locations produce 15,000 to 200,000 t of filter cake a year. An average annual tonnage is about 25,000 to 50,000 t.
A selection of clay mineral filter cakes can be found in the chart below. Analogue access via raw material map.
|Reference Number||Raw Material||Location||Type||Image||Data Sheet|
|6406||Rogoźnica II||58-152 Rogoznica, Polen||Filter Cake||Download|
|6391||Durmersheim||76448 Durmersheim||Filter Cake||Download|
|6390||Aue||08280 Aue||Filter Cake||Download|
|6386||Taben-Rodt||54441 Taben-Rodt||Filter Cake||Download|
|6365||Scheda||57489 Drolshagen||Filter Cake||Download|
|6362||Saalburg||61381 Friedrichsdorf||Filter Cake||Download|
|6357||Ankum||49577 Ankum||Filter Cake||Download|
|6354||Hahnstätten||65623 Hahnstätten||Filter Cake||Download|
|6352||Caminau||Filtercake Caminau||Filter Cake||Download|
|6350||Kriechbaum Sialin||4284 Kriechbaum, Österreich||Filter Cake||Download|
|6317||Freihung||92271 Freihung||Filter Cake||Download|
|6263||Grevenbrück||57368 Lennestadt||Filter Cake||Download|
|4050||Untschen||04626 Nöbdenitz||Filter Cake||Download|